Author Topic: '74 CB550 "Pile o' Parts"  (Read 3272 times)

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Offline TheVet

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'74 CB550 "Pile o' Parts"
« on: October 25, 2020, 12:51:02 PM »
Greetings all!  First time poster, currently embarking on my 2nd build...  I did a cafe-style CB350 a few years ago and realized I don't really like riding it that much (it was built on a tight budget and feels like it), so I decided to dip my toes in the SOHC4 waters and build the bike I've always wanted to do - a CB550.  Picked up a bit of a basket case '74 a few weeks ago as a literal pile of parts - no title, no idea when it last ran, definitely missing pieces, but it was cheap and turned over nicely so here we are.  Been slowly getting a feel for where the motor is at over the last week or two, figured I'd start a build thread here to document progress and hopefully glean a bit of the vast collection of knowledge on this site.

Goals for the build:

 - Stock motor +/- mild performance "bolt ons" (will probably try a 650 cam at least)
 - Eliminate excess weight!  Would like to get this beast close to 350lbs dry if possible
 - Will probably go full motogadget for electrical, seems like the easiest route
 - Modern USD front end swap, probably of CBR-origin

I have a proper track bike for going fast, so with this bike there will undoubtedly be concessions made to aesthetics - just hoping the end result inspires a little more confidence than my 350  ;D

Here are a couple pictures of the bike on day 1 to start things off:




« Last Edit: March 05, 2021, 12:29:59 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline Kelly E

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Re: '74 CB550 "Pile o' Parts"
« Reply #1 on: October 25, 2020, 01:01:28 PM »
That's about how my 74' 550 looked 3 years ago when we bought it. I did tapered roller bearings and Progressive brand springs in the front. I put on Hagon shocks and converted the swingarm to needle bearings. These bikes handle nice already, I am almost done with the bike, I have a build thread on here too.
Never Give Up - Never Surrender

The Rust Bros. Garage Collection
1974 Honda CB 550 K0                                            1971 MGB/GT
1975 Honda CB 400F Super Sport                          1972 MGB/GT
1977 Kawasaki KZ 1000 LTD                                   1985 GMC S15
1978 Kawasaki KL 250
1980 Suzuki GS 1100E
1982 Honda CB 900F Super Sport
1983 Honda CB 1100F
1984 Honda VF 700S Sabre
1984 Honda VF 1000F Interceptor
1990 Moto Guzzi 1000 Le Mans
1994 Kawasaki Concours ZG 1000A9
2005 Harley Davidson Fat Boy

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #2 on: November 01, 2020, 05:31:46 PM »
Been busy getting some preliminary work done the past week; job #1 was making sure the thing will actually run before I go dumping $$$ into it.  Initial compression readings were disappointing (~60 across the board), but I figured I'd see if they improved after running since the bike has obviously been sitting for some time... 



Carb rebuild went fairly smooth, save for a couple stuck float pins that lead to broken float posts - little JB weld and some re-purposing of the old slide needles seems to have done the trick.  Used the tiny ultrasonic cleaner HF sells - $80 well spent IMO, and highly recommended to anyone on the fence about buying one.  You'll have to do things in batches since it'll only fit 2 carb bodies at once, but I'd pull apart one carb and run it through the cleaner while I was taking down the next carb. 



Before:


After (no scrubing, just 2 rounds through ultrasonic):


Repairs:




New Delkevic 4-into-1 exhaust looking very slick  8)  Also a little sneak peak at the tank I'll be running...




And after a little ghetto-rigging of the ignition and starter circuits, she pretty much fired right up! 



Ran for ~5 minutes and rechecked compression, unfortunately there seems to have been no improvement - still registering right around 65-70 across the board.  I'm debating whether or not I should try to get a reading with a better compression tester, since I'm using a cheap HF rig and it strikes me as a little odd that the numbers are all #$%* but also within 10%...  But, probably worth rebuilding the top end anyway, so perhaps it's a moot point?
« Last Edit: March 05, 2021, 12:33:36 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline PeWe

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Re: '74 CB550 "Pile o' Parts"
« Reply #3 on: November 02, 2020, 06:35:57 AM »
Throttles fully open while cranking measuring the compression?
« Last Edit: November 02, 2020, 07:33:55 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #4 on: November 02, 2020, 06:17:38 PM »
Ha, totally forgot about that bit since the carbs were off the first time I checked...  Rechecked this evening, improved but still low (~100).  No change with a few drops of oil either. 

Top end rebuild it is!
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline rb550four

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Re: '74 CB550 "Pile o' Parts"
« Reply #5 on: November 02, 2020, 08:50:25 PM »
  Only 5 mins.running may not clean out those rings depending on if they stayed dirty in the stuck in the position from laying dormant for so long. I've found that some rings just take a while to remove or loosen up even by hand on some engines, because the rings are so tight in their groove loaded with crap or rusted from condensation. I have a couple pistons laying around here that I never got the rings loose on and I tried almost everything to get them free.
  Are you running a fan on the engine while it's running like you would when you sync the carbs? Are your valves seating properly and adjusted properly? I've had a couple of engines that were so loaded up with lead on the valves that it was a wonder that it ever ran at all. Don't forget to adjust the cam chain tentioner.
  Oil change already I hope, no telling what is laying in the pan that may find it's way around the lower end. I always drop the pan to see what kind of goodies lay at the bottom and check the cam chain and primary chain condition  for stretch while I'm there to see if there is a chance I don't have to split the cases....They were all good only twice out of 27 engines at my house.
  Lastly have you witnessed any oil weeping from the head gasket on the the outside of #1 and #4 ,Those old o rings are always no good and need replace along with the head gasket ,so if you might be thinking you don't want to take off the top end and see what's what,you may find now is the perfect time to change that stuff and get a good look-see about the condition of the valvetrain and change out the seals, gaskets and pucks so you don't end up with a poor running engine that's a bleeder. Then you get to do it anyways and wonder why you didn't in the first place.And of course,if you've gone that far you should just pull the jugs  to inspect the piston, rings and the condition of the cylinders....so you don't ask yourseld why you didn't. Then when you feel confident that you won't have these issues arising again , then feel free to spend as much on fun parts you want to complete the machine...so you don't ask yourself why you didn't do all of this in the first place after you spent too much $ on a beat machine that you really had no idea what condition that engine was in.  Two Cents. But most of all enjoy the build ,learn from the build and be    the build. and have fun.
« Last Edit: November 02, 2020, 08:53:07 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline rb550four

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Re: '74 CB550 "Pile o' Parts"
« Reply #6 on: November 02, 2020, 08:56:52 PM »
Oh and one more thing , Check the shifter and the kickstart  to see if they work properly . shift through all gears to be sure the dogs aren't frozen. be sure the kick starter works and returns  too. Hate to see you get through my last post and have to do it twice because you need to split the cases  and fix this stuff.
  This activity happens to every "unknown" motor I get a hold of, only because, I hate to wonder why I didn't do something when I had the chance to do it in the first place....and didn't.

« Last Edit: November 02, 2020, 09:05:40 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #7 on: November 04, 2020, 06:08:27 PM »
I hear you.  Kinda feeling I should pull it apart regardless, just so it's been done.  My only worry is getting bit by the "while I'm in here" bug and ending up down a hot-rodding rabbit hole, which is not the goal of this build. 
« Last Edit: November 04, 2020, 06:10:50 PM by TheVeterinarian »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline rb550four

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Re: '74 CB550 "Pile o' Parts"
« Reply #8 on: November 04, 2020, 06:57:40 PM »
  You can show some restraint, unless you find that there is a bunch of machine work to be done, then by all means go wild , you'll probably be looking for new pitons and rings if  the cylinders are screwed. And if the valves were to be very messed up and you had to send it out the head, well since it's going out anyways, might as well polish up those intake airways too and might as well change out those valve guides , they could be cracked right? Valve seats  maybe,depends on their condition.
  Restraint, change parts that only need to be changed to get the desired effect of a decent running, dependable machine using what is within specs. There's nothing wrong with just a hone if you have the room  then you may able to reuse pistons but get new rings. Oh and check those bearings while you have those cases split.
  Of course ,the choices are up to you and the condition of what you have. Sensible restraint would be something that may also be achieved, so they say, but few have been able to pull it off or so I've heard. It may just be a wive's tale, can't say for sure if it's even a real possibility here since you rolled out the word HOT ROD. That sounds expensive doesn't it. What ever happened to maybe just a 650 cam? Just kidding , do what you do, but have fun doing it.
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #9 on: November 09, 2020, 07:05:59 PM »
Got the top end off yesterday, pretty uneventful.  Piston #4 has a concerning chip on the lateral edge - strangely there is no corresponding score mark in the bore, but it's definitely not just a flake of metal sitting on there...  Thinking this probably means new pistons, which prompts the question of what to use:  I've noticed that several of the top-end rebuild kits out there from the likes of 4-into-1, Common Motor, etc, have an option that includes pistons for not that much more than the rebuild kit itself - better to avoid these, or are they good to go?  Not sure I want to spring for fancy hi-comp pistons given the goals of the build...  But also, not sure I don't either.
« Last Edit: March 05, 2021, 12:19:59 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline PeWe

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Re: '74 CB550 "Pile o' Parts"
« Reply #10 on: November 10, 2020, 01:46:33 AM »
Happened at assembly?
Cylinder block dropped over the piston. The sharp edge of sleeve rammed the piston that sat tilted against upper case.

Do not ask me how I know ;D
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #11 on: November 17, 2020, 08:18:36 AM »
Took the pistons out last night for a little clean up and closer inspection, turns out #4 is pretty thrashed...  Kinda surprised the bore isn't worse off, honestly - it really doesn't look substantially worse than the other 3.  There is some light scoring, but nothing I can catch a nail on other than the ridge at the top.  So new pistons for sure at this point; wondering if y'all think those bores will clean up with just a hone or if I should just bite the bullet at this point and have a new set of oversize pistons bored in?






« Last Edit: March 05, 2021, 12:38:33 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #12 on: November 24, 2020, 01:27:17 PM »
Last few weeks have been a tale of indecision:  Decided I'd start by honing the questionable cylinder out to the service limit and see if that was enough to clean it up - and of course, it wasn't.  So, it was looking like I'd need to bore them - and if I was going to bore it out I'd need all new pistons, and if I needed all new pistons I might as well do forged hi-comps, right?  Still wasn't really feeling that, so I decided I'd try a new set of cylinders first since a couple of my fins were broken and it all looked kinda #$%*ty anyway.  Then I got stuck on what to do for pistons - whether I try to do one NOS or replace them all with some kind of aftermarket set - and finally settled on a set from Cruzin Image at the recommendation of several folks here.  BUT, then I read Hondaman's recommendation on having the cylinders bored out regardless of condition and ultimately opted for the 0.5mm overbore kit.  *Sigh*  Now to find a good local machine shop!


« Last Edit: March 05, 2021, 12:38:52 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline rb550four

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Re: '74 CB550 "Pile o' Parts"
« Reply #13 on: November 24, 2020, 05:06:59 PM »
  Decisions ,decisions, part of the game. Remember that you started with and named this build "pile o parts " for a reason. Have no fear you are rounding the bend. You now know whats good and know what isn't and have made up your mind how to make it all good. That in itself is a massive move forward in just a half page. When your parts are in and the rest comes back from the machine shop you'll be well on your way to assembling a finished project. How great will that be? Especially when you had just a pile of parts, not knowing the condition of any of the parts you had, and it wasn't that long ago since you started.
 That being said and not to get ahead of ourselves here, have you checked the kick start lever operation,the shifting to make sure you have access to all the gears( bumping it won't give you the condition of the shifting dogs but it will let you know if they are frozen or not).
  You could take the chance and not do anything but the top end, but without checking the bearings and looking for cam chain wear (or just replacing it) and primary chain stretch (or just replace it) and check the condition those nasty little roller bearings just behind the oil pump , if you can live with it . But if your a kick yourself for not doing something while you were there kind of guy, know that this is your big chance to change out  both your crank gaskets, check transmission condition , give that bottom end and oil journals a good blowing out plus the stuff in the last paragraph  without tearing down anything that you haven't put together yet. Nobody like to do things twice . I find that in an unknown engine, it relieves any doubt of success and offers years of uninterrupted enjoyment . Nobody needs a new project that was your last project. I might, but you don't. Just sayin', you know that life is full of choices and decisions and like like the knight in Indiana Jones said"you must choose wisely".Great job , good progress, and it should always be fun.
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline PeWe

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Re: '74 CB550 "Pile o' Parts"
« Reply #14 on: November 25, 2020, 05:50:59 AM »
Better to restore/repair a little bit extra than need to redo it.
Too much work to take engine apart. Redo means new gaskets/seals if used.

There is a difference between service limits and "assembly" limits.
A part can be not good enough to reuse when assemble the engine,
 but not worn enough to be a reason to take engine apart.

Valves, guides, chains etc. They need to be worn to be a reason to open engine to replace them.
But when engine already is apart, why use parts with not much life left?

It is not fun to ride a smoker after a restore.
Worn bores, pistons, valves, guides make engine to run bad.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Erny

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Re: '74 CB550 "Pile o' Parts"
« Reply #15 on: November 25, 2020, 06:07:15 AM »
Been busy getting some preliminary work done the past week; job #1 was making sure the thing will actually run before I go dumping $$$ into it.  Initial compression readings were disappointing (~60 across the board), but I figured I'd see if they improved after running since the bike has obviously been sitting for some time... 



Carb rebuild went fairly smooth, save for a couple stuck float pins that lead to broken float posts - little JB weld and some re-purposing of the old slide needles seems to have done the trick.  Used the tiny ultrasonic cleaner HF sells - $80 well spent IMO, and highly recommended to anyone on the fence about buying one.  You'll have to do things in batches since it'll only fit 2 carb bodies at once, but I'd pull apart one carb and run it through the cleaner while I was taking down the next carb. 



Before:


After (no scrubing, just 2 rounds through ultrasonic):


Repairs:




Re-jetting with 110 mains and 40 pilots for planned open exhaust and velocity stacks


New Delkevic 4-into-1 exhaust looking very slick  8)  Also a little sneak peak at the tank I'll be running...





And after a little ghetto-rigging of the ignition and starter circuits, she pretty much fired right up! 



Ran for ~5 minutes and rechecked compression, unfortunately there seems to have been no improvement - still registering right around 65-70 across the board.  I'm debating whether or not I should try to get a reading with a better compression tester, since I'm using a cheap HF rig and it strikes me as a little odd that the numbers are all #$%* but also within 10%...  But, probably worth rebuilding the top end anyway, so perhaps it's a moot point?
Interesting result after ultrasonic cleaning - what fluid you used?
CB750K K7 USA model (1977)
CB550K1 USA model (1975)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #16 on: November 25, 2020, 07:39:01 AM »
Used one of those gallon buckets of carb cleaner - perfect volume for the HF cleaner.  That said, it did crap out on me last week so...
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #17 on: November 30, 2020, 04:24:36 PM »
What's that under the tree?  New pistons, fresh from Japan!  Ended up going with an 0.5 oversize set from Cruzin Image and will have them bored in as per Hondaman's recommendations. 





« Last Edit: March 05, 2021, 12:40:17 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #18 on: February 24, 2021, 07:57:57 PM »
Long time no post... 

Been working sporadically here and there, but between cooler weather and residency match season progress has been slow.  Will update more thoroughly later, but for tonight I have a more pressing issue for y'all:

Set about tearing down the head for a valve job this evening, and once I got some carbon cleaned out of the combustion chambers I noticed there's actually quite a bit of damage from whatever #$%* was bouncing around in cylinder 4...  It appears to be confined mainly to the squish band (fortunately the valve seats are intact), but it ain't pretty.  Is it worth pressing forward with this head since this isn't intended to be a high-performance motor, or should I scrap it and start fresh?



'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline calj737

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Re: '74 CB550 "Pile o' Parts"
« Reply #19 on: February 25, 2021, 05:10:40 AM »
It needs to go to a machine shop for sure. They will need to surface it, weld up the gouges, then re-surface it before that head is usable again.

Ask me how I know... (Dropped a valve on my Boxer). But she's back and running great.
'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 bwaller

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Re: '74 CB550 "Pile o' Parts"
« Reply #20 on: February 25, 2021, 04:39:08 PM »
You can probably tidy any high spots up by hand and live with the divots. It would be wise to have a shop straighten the deck though.

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #21 on: February 26, 2021, 08:30:02 AM »
My main concern is that it will make the bike hard to tune, since the combustion efficiency in cylinder 4 will likely be different than the other 3.  Not sure if I'm splitting hairs here though...
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #22 on: March 05, 2021, 12:57:37 PM »
Chassis updates:  Nabbed a CBR600RR front end a while back for my front end swap.  Decided on the 600 front end (specifically the '05-06 model) for a couple reasons:  I am trying to avoid needing an expensive aftermarket triple (Cognito...) to correct geometry and the 600 in general has a little more offset than most sportbikes (32.5mm vs 28-30).  Specifically, the '05-'06 forks are the shortest of the lot, which helps with the other things I need to do to reign in the increased trail resulting from reduced offset.  Also, I wanted a Honda logo on the top triple for continuity  ;D



Out with the old, in with the new. Rounded the package out with a nice new front wheel / cognito conversion hub (which cost more than 2x the rest of the bike :o)







Having test-fit everything, I can confirm the '05-'06 CBR600RR front end is a DIRECT SWAP for the 550 unit.  Stem diameter and length is identical (no conversion parts needed), top nut threads carry over, and even the steering stops work properly!  Super slick!  Downside to this particular swap is that I had a much harder time finding the 600 front end (GSXR forks are dime-a-dozen in comparison), and most parts for '05-'06 forks are slightly different than '07+ which means sourcing them is also harder.  That said, still very happy with the end result so far!
« Last Edit: March 05, 2021, 01:18:47 PM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #23 on: March 05, 2021, 01:15:56 PM »
Next up, stripped everything down to a bare frame and rigged up a little makeshift blast booth in the garage with a cheap HF portable media blaster and a rented compressor.  Made a huge mess but worked quite well!







Took advantage of everything being set up and soda blasted the motor as well

'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline calj737

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Re: '74 CB550 "Pile o' Parts"
« Reply #24 on: March 05, 2021, 02:56:51 PM »
Soda blasting the engine assembled is risky. Any of that media once contacting oil will coagulate and cost you big time.

Remove the covers, the oil passage plugs and flush it really well with kerosene or diesel to rinse the soda away. I’d probably remove the valve cover and cam too and make sure to drain the motor really well. Then use cheap 30w oil and manually circulate it through all the passages and drain it and change the filter. Gotta be sure now or regret it later-
'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 SOHC4 Cafe Racer Fan

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Re: '74 CB550 "Pile o' Parts"
« Reply #25 on: March 05, 2021, 05:16:02 PM »
Soda blasting the engine assembled is risky. Any of that media once contacting oil will coagulate and cost you big time.

Remove the covers, the oil passage plugs and flush it really well with kerosene or diesel to rinse the soda away. I’d probably remove the valve cover and cam too and make sure to drain the motor really well. Then use cheap 30w oil and manually circulate it through all the passages and drain it and change the filter. Gotta be sure now or regret it later-

Good advice.  Oil starvation will kill your motor.
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 TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #26 on: March 08, 2021, 11:06:25 AM »
Good to know.  The whole thing is coming back apart for rebuild anyway (although I'm trying not to split the case), this was more just to get it all in one shot while trying to keep the bottom end sealed up as best possible.  Was planning on flushing everything out either way.
« Last Edit: March 08, 2021, 11:08:15 AM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #27 on: April 12, 2021, 10:03:41 AM »
More progress from the last month, starting with frame mods / detab:





Decided to try repurposing the discarded passenger foot peg mounts as a mounting point for rearsets - they actually fit very nicely! 



All cleaned up, with my own pointed "tail hoop" mocked up:



'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #28 on: April 12, 2021, 10:21:47 AM »
Next up, tail cowl shaping and fabrication:  I usually buy a sheet of rigid insulation board, cut out a few squares and glue them together to form a block, and then cut/sand it down to shape from there.  I prefer the rigid insulation board because it's cheap, sands down nicely, and holds up to some abuse but can still be cut easily with a carving knife.  Hand-shaping these on the bike is one of the more purely artistic and enjoyable parts of the build process for me, but damn I hate working with fiberglass.

Rough cut


Sanded down to the basic shape I was going for


And the final form, after a lot of massaging:


Filling in gaps with some expanding foam to make sure everything fit to the frame nicely before fiberglassing


Used painter's tape coated with carnauba wax to help release the fiberglass part from the form -worked great!  Would recommend several layers of tape though, the resin ended up seeping through and melted my form :(




« Last Edit: April 12, 2021, 10:25:48 AM by TheVet »
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #29 on: April 12, 2021, 11:19:57 AM »
Changed directions a bit and switched over to putting the motor back together.  Task #1 was getting the head sorted:  Ended up using the one that came off the bike with a kinda chewed up squish band on #4; hopefully I don't regret putting some work into it instead of trashing it...  Accordingly, I didn't want to go too crazy with serious headwork but figured I could tackle a quick port match and light smoothing of casting lines in the intake runners.


Next up, I found a good video from Common Motor on DIY head/deck leveling and decided to give that a whirl; good thing I did though, because the head ended up needing a fair bit to get it nice and smooth all the way across. 




After that, it was just a standard valve job and things were good to go!  Ended up making my own tool to compress the valve springs - a little janky, but it got the job done. 




'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)

Offline SOHC4 Cafe Racer Fan

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Re: '74 CB550 "Pile o' Parts"
« Reply #30 on: April 13, 2021, 08:12:02 AM »
You may want to reinforce those passenger peg mounts with some additional material.  They flex a bit.
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 TheVet

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Re: '74 CB550 "Pile o' Parts"
« Reply #31 on: April 14, 2021, 06:48:18 AM »
For sure.  Fortunately I'm pretty light, but the pegs on my 350 do still flex a little and it annoys the crap out of me when they're not perfectly straight...  Worst case I'll just throw on some Cognito rearset mounts, but figured I'd try this first since they're free  8)
'74 CB550 "Pile o' Parts" (in progress)
'71 CB350 "Project Cafe" (done)
'06 Daytona 675 "Genesis" (track bike)