Author Topic: 1975 CBB550 build- very first bike and first build  (Read 15497 times)

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Online calj737

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Re: 1975 CBB550 build- very first bike and first build
« Reply #25 on: August 12, 2015, 04:09:40 AM »
Well, if you abandon the notion of fuel as the culprit (I wouldn't) and assess the electrical as the problem, you quickly run into some contradictory facts:

#1 & #4 cylinders are paired by the ignition, as are #2 & #3. So, if you were having a problem with points, condensers, or coils, then you would see the issue of cold pipes and fouled plugs/dry plugs on these paired cylinders. You are not.

With cylinders 2/4 running very rich, this is definitely a fuel problem. You are getting spark to 2/4 but it can't burn the amount of fuel. You could argue the spark isn't strong enough, but it's still not strong enough for the amount of fuel present.

And because your spark is present on one side of the coils, but not the other, this is pretty hard to declare as an electrical issue. Of course, it's possible that you have the spark plug wires wrong? Left side coil wires to both outside cylinders (1/4) and right side coil to inside cylinders 2/3). Is this how you have them?

Even when there is no fuel, the spark plug firing will warm up the pipe a little bit. So is the exhaust dead stone cold, or much, much cooler than 2-4?

And final nail in the coffin on electrical being the issue is:
"Fuel is misting out the intake side as well".

So taken in total, the evidence (I'm assuming you've got the spark plugs wired properly) is clearly fuel. start by performing a clear tube method level of your carbs. Please snap Somme pictures of each carbs level.

If you've bench synched them, they will run pretty well. Maybe not perfectly, but pretty well. Also, make sure the fuel line routing from the test tank is mostly straight downhill avoiding any loops below the fuel inlet.

And before you re-test, clean or replace the fouled plugs. Continued use of them will distort your findings.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #26 on: August 17, 2015, 07:48:37 AM »
So its been nothing but rain the last week or so and progress slow.  In following the above advice, I've gone through the carbs again.  Every nut and bolt were pulled apart again, inspected, and reassembled.  The floats again checked and bench synced.  I didn't find anything suspicious in terms of contaminates or maladjustments.  Still no improvement. 

A local shop offered to through them on a running 550 they were doing front end work on.  They've been great in sourcing quality rebuild parts and for advice.  After a quick bolting up, the test-bike fired and ran amazing.  While I'm glad my carb rebuild skills are somewhat intact.  The frustration continues regarding the engine firing situation.

While I'm tempted to just tear it all down and rebuild from scratch, I want to make sure that the PO didn't ruin the engine and only find out after I've put a bunch of time/money into it.  From here I'm going to be going through the ignition system piece by piece, which may necessitate a re-wiring of much of the bike.  Its tempting to just rewire the entire thing, with the PC-8 or Motogadget stuff.  Both look like tempting.

As always, I welcome the advice and suggestions of all.  Apologies to CB750 Cafe Racer Fan for any grammatical mistakes you feel inclined to correct. ;D

Offline streak09

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Re: 1975 CBB550 build- very first bike and first build
« Reply #27 on: August 17, 2015, 09:39:40 AM »
... Its tempting to just rewire the entire thing, with the PC-8 or Motogadget stuff.  Both look like tempting.

In my opinion, I wouldn't hesitate to rewire. The PO of my 550 did some weird stuff, so I decided it was worth the piece of mind knowing 100% what is going on so I rewired. I know some people may disagree and say you should leave it stock for future owners, and I understand, but I also think it is my duty to keep the trend of "POs that didn't know what they were doing" going strong  ;D.

I rewired mine from scratch and there isn't much too it. I left out a lot of stuff that I didn't find completely necessary in the original wiring. I'm not completely done yet, but it runs and charges fine. I have a PDF wiring diagram that I can pass along if I sell.  I didn't use any of the units you listed, just some terminal blocks. Just my 2 cents.


Carbs look amazing by the way! I went through an entire rebuild early this spring and know how tedious it is.

Best of luck. 


Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #28 on: August 17, 2015, 11:34:58 AM »
Thanks streak!  Where did you score the new wiring?  I haven't really found anywhere local to simply get it by the foot that resembles the stock coloring. I don't plan tfor run anything complicated either so my wiring will likely be straight forward as well.

Online calj737

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Re: 1975 CBB550 build- very first bike and first build
« Reply #29 on: August 17, 2015, 03:04:14 PM »
I happy to drop past tomorrow late afternoon and have a look now that I'm in FL for the week. As for stock wiring product, a Dime City down in St Pete/Largo has spools available of stock-ish stuff and you can drop in and buy it there. Or order from McMaster Carr and it will be here in 1-2 days.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #30 on: August 19, 2015, 03:19:50 PM »
Hey Cal, thanks for the offer. Sorry I got back to you late.  I've got some wiring stuff on the way and am running through the chop job PO had done. Started to polish the intake manifold and drawing up a cowl section as a distraction. Photos to follow.

Online calj737

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Re: 1975 CBB550 build- very first bike and first build
« Reply #31 on: August 19, 2015, 04:48:36 PM »
well Im still in Orlando for 16 hours more. Ring out if you want a set of eyes-
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #32 on: August 28, 2015, 07:33:58 AM »
Well the bike has been on the back burner for a couple weeks.  Got back into it today with fresh eyes.  Went through the ignition system and was wired correctly, although the quality wasn't great.  Replaced some wiring and cleaned the rest up.  Set the timing and put in new plugs.  Still no change.

Checked the compression and 1-3 had almost none, while 2-4 were 80-90ish.  Not promising.  The prior owner said some "headwork" had been done by the guy he got it from, which is likely the issue.  I'm going to check the valves for proper adjustment hoping that is the issue.  If not, I'm betting its got worn rings/cylinders.

As always, any thoughts or suggestions are appreciated.

 

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #33 on: August 28, 2015, 07:38:48 AM »
I happy to drop past tomorrow late afternoon and have a look now that I'm in FL for the week.

Damn! How did I miss that post? I'd have rode up just to bust your chops!  ;)
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Online calj737

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Re: 1975 CBB550 build- very first bike and first build
« Reply #34 on: August 28, 2015, 09:13:01 AM »
I happy to drop past tomorrow late afternoon and have a look now that I'm in FL for the week.

Damn! How did I miss that post? I'd have rode up just to bust your chops!  ;)
you;; have another chance, I'll be in Orlando (again) 9/8-9/12. Between the 3 of us, we should be able to coax at least 60HP out of this little monster and get it running in about 6 hours????  ;) I'll plop my 500 motor in it, bring my extra MotoGadget m-gear and we'll have some fun!
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #35 on: August 28, 2015, 09:20:18 AM »
I happy to drop past tomorrow late afternoon and have a look now that I'm in FL for the week.

Damn! How did I miss that post? I'd have rode up just to bust your chops!  ;)
you;; have another chance, I'll be in Orlando (again) 9/8-9/12. Between the 3 of us, we should be able to coax at least 60HP out of this little monster and get it running in about 6 hours????  ;) I'll plop my 500 motor in it, bring my extra MotoGadget m-gear and we'll have some fun!

And I'll bring the cutting torch and sawzall!  :o  ;)  8)
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #36 on: August 31, 2015, 12:33:51 PM »
After checking the valves, most were WAY too tight and I couldn't even get my smallest feeler gauge in there.  I was hoping this was the issue.  I adjusted all valves, kicked it a few and rechecked.  Checked compression again and no change.  Oh well, it looks like I'll be tearing the top end off. 

I'm torn between having the head checked out vs simply getting a new one given the PO's claimed P&P job and valve/spring upgrades on it.

In terms of pistons/cylinders, I'm hoping I can simply hone the cylinders and replace the rings on the stock pistons.  Hoping to avoid boring and new pistons.  Any thoughts?

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #37 on: August 31, 2015, 12:44:23 PM »
Are you checking the compression with the throttle wide open? The throttle slides (when closed) can restrict the intake enough to have a negative impact on your compression test readings.
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #38 on: August 31, 2015, 01:20:56 PM »
Yea, throttle is wide open and without filters. Choke is open as well. Two cylinders have almost no compression. What meeting how much of that is rings and how much is PO destroying the head.

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #39 on: August 31, 2015, 02:00:36 PM »
Yea, throttle is wide open and without filters. Choke is open as well. Two cylinders have almost no compression.

Well, once you've got the head off it should be pretty easy to tell from there. If the valves are leaking it might be a good idea to at least hone the cylinders and re-ring the pistons at the very least.

Overbores are more fun though!  8) There's no replacement for displacement!  ;)
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #40 on: August 31, 2015, 02:45:31 PM »
Thanks for the help.  The overbore stuff is certainly tempting but I worry how deep the rabbit hole goes on the small 550.  My initial plan was really just to get a fun driver to cruise around on a bit.  I have 750 basket case that I intended to all out with on a longer-term project and pass the 550 down to the GF.

I don't want to cut corners on the 550 but didn't want to go ape on the thing either.  Do you think I could get away with new rings, a cylinder hone and have the head looked at?  I'd like to get a machine shop to check the head to make sure the PO didn't wreck it too.  If I'm pulling it that far apart, I'd like to do it once and right the first time.

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #41 on: August 31, 2015, 03:02:54 PM »
As for the head, you can turn it upside down once it's removed and fill the combustion chambers with alcohol or acetone to check the valve sealing. NO SMOKING/PILOT LIGHTS/OR ANY OTHER IGNITION SOURCE NEARBY (including air compressor or other electrical motors).

As for rings, you'll have to measure the pistons and bores for wear to determine whether just a hone and rings will work.

cruzinimage has pistons with rings and head gasket on ebay for $120:

http://www.ebay.com/itm/Honda-CB550F-CB550K-600cc-Bigbore-Piston-Kits-Head-Gasket-CB550FBB-/161744449539?vxp=mtr&hash=item25a8b87003

CycleX or A.P.E. should be able to do the re-bore for $150 to $200. Just have to call to confirm and then ship the cyls and pistons.
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #42 on: August 31, 2015, 03:14:38 PM »
Thanks for the info!  I might go bored after all.  ;D ;D ;D  That was FAR less than I expected, although I admittedly hadn't investigated thoroughly yet.

I'll post some photos once its torn down and see whats what.

Offline SOHC4 Cafe Racer Fan

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Re: 1975 CBB550 build- very first bike and first build
« Reply #43 on: August 31, 2015, 03:27:44 PM »
You can also select a minor .5 or 1mm oversized piston from cruzinimage to reduce the cost of boring.  If you cylinders check out, you may only need to hone the sleeves and get new rings.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline madmtnmotors

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Re: 1975 CBB550 build- very first bike and first build
« Reply #44 on: August 31, 2015, 04:01:13 PM »
Didn't see the .5mm or 1mm at the cruzinimage ebay store. DSS has .25mm oversize which would run just over $230 plus shipping:

http://www.davidsilverspares.co.uk/CB550K1-1975-USA/part_70607/
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline SOHC4 Cafe Racer Fan

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Re: 1975 CBB550 build- very first bike and first build
« Reply #45 on: August 31, 2015, 04:12:10 PM »
Didn't see the .5mm or 1mm at the cruzinimage ebay store. DSS has .25mm oversize which would run just over $230 plus shipping:

http://www.davidsilverspares.co.uk/CB550K1-1975-USA/part_70607/

The DSS pistons sound like a good option if upping performance is not a priority versus keeping it as stock as possible.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline madmtnmotors

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  • Sunny Central Florida
Re: 1975 CBB550 build- very first bike and first build
« Reply #46 on: August 31, 2015, 04:15:38 PM »
Didn't see the .5mm or 1mm at the cruzinimage ebay store. DSS has .25mm oversize which would run just over $230 plus shipping:

http://www.davidsilverspares.co.uk/CB550K1-1975-USA/part_70607/

The DSS pistons sound like a good option if upping performance is not a priority versus keeping it as stock as possible.

Plus, it still leaves room for a future overbore. There are at least two threads here that I stumbled across:

http://forums.sohc4.net/index.php/topic,151007.msg1725064/topicseen.html#msg1725064

http://forums.sohc4.net/index.php/topic,112346.125.html
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline Bootsey

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Re: 1975 CBB550 build- very first bike and first build
« Reply #47 on: August 31, 2015, 05:22:19 PM »
If you want to go +0.5mm, you can buy CB500 +3mm pistons - that brings the bore to 59mm, which is +0.5mm from stock 550.

http://www.ebay.com.au/itm/Honda-CB500K-CB500F-553cc-Bigbore-Pistons-Kit-59mm-W-Head-Gasket-CI-CB500KBB-/131238402760?hash=item1e8e6b1ac8

Offline CBertels

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Re: 1975 CBB550 build- very first bike and first build
« Reply #48 on: August 31, 2015, 07:45:05 PM »
Thanks for all the input. I'll get some estimates from the show suggested on the condition of the cylinders and recommendations. I like the 600cc idea given that the piston/rings/etc. seem to be a bit less than the .5 or .25 kits offsetting the cost of machining.

Any non-obvious pros/cons with going the 600cc route?  Will carb tuning be a nightmare with the larger bore?

Offline SOHC4 Cafe Racer Fan

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Re: 1975 CBB550 build- very first bike and first build
« Reply #49 on: August 31, 2015, 08:04:20 PM »
Tuning will not be a nightmare.  If you want to maximize the gains from any big bore kit, add a cam (you can swap in a 650 cam which will be your cheapest option) and port the head to improve flow of gas and air into and out of the head. 

The 600 cruzinimage kit is affordable.  Note: it does not increase the compression, so higher compression/smaller big bore kits like the Wiseco or Dynoman kits will create more power.  That said, you will still get a broad improvement to torque and horsepower from the cruzinimage kit. 
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold