Author Topic: 1978 cb550 FKR Mutt  (Read 18859 times)

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Offline nevikwen

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Re: 1978 cb550 FKR Mutt
« Reply #50 on: September 22, 2016, 12:57:08 AM »
Thanks for the great insights Cwchan!

Kev

Offline Bashj

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Re: 1978 cb550 FKR Mutt
« Reply #51 on: September 22, 2016, 09:57:23 AM »
very nice looking bike!   I just got a 76 cb550 im going to be building.

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #52 on: July 04, 2019, 02:57:18 PM »
So an update.

I had originally put the engine back together a few years ago.  In my naivete' i neglected to check & get the cylinders honed and replace the rings and so the engine always ran rough.  I moved back to Edmonton and so i have to get an out of province inspection so i've reopened the engine and did what i should have originally.  I did over torque the cylinder head nuts though... so we'll see what happens.  Got the ignition timed and the carbs synced.  Boy, this thing really purrs now!!  There are a few other things i need to do..

Hopefully it will pass  inspection !
« Last Edit: July 04, 2019, 07:47:46 PM by cwchan »

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #53 on: August 16, 2019, 11:05:33 AM »
Whooot Whoot!  I'm on the road again!!

I had to get new tires to pass safety but other than that everything was good

Driving around after honing the cylinders i still have some trouble.  I now suspect its the advance springs that are on the mechanical advance.  It runs well at 2500+ rpm but i get some inconsistencies below that.  It also idles differently when its 5-10 min warmed up vs when its cooler but choke is not pulled out.

Currently i have the dyna s with 5 ohm coils statically timed on the full advance.  Dynamically, i can see that its appropriately timed at full advance at 2500 rpm but when i bring it down to 1000 it doesn't return all the way to the F mark.  I haven't yet checked the rpm at which it actually reaches full advance though. 

I have a spare mechanical spark advancer i can switch out, see if there are differences.  If things don't get better, I'll try cutting the springs a bit.  I also still have the points plate that came with the bike.  I had thought about going back to points and even bought a Hondaman transistor but got intimidated with setting it up

Offline cwchan

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1978 cb550 FKR Mutt
« Reply #54 on: September 05, 2019, 08:52:25 PM »
I did a bit of tuning. One thing I found is to ensure that the bigger crankcase nut is centered to the smaller crankcase bolt. There was some slight wobble that was throwing off the ignition timing.

The advance springs are good


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« Last Edit: September 05, 2019, 08:54:05 PM by cwchan »

Offline rusty2078

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Re: 1978 cb550 FKR Mutt
« Reply #55 on: September 06, 2019, 09:33:08 AM »
Hi CW, reading your posts and seeing that you're back in Edmonton...a good resource is The Bike Shoppe (SE, just south of SHWD PK freeway, and east of 50/66/Gretzky), if you're not aware of them. Great guys that will dispense advice, and if you need work done, keep you informed at every step. Nice to have an independent shop that isn't a boutique dealership!

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #56 on: September 07, 2019, 07:56:45 PM »
Hi CW, reading your posts and seeing that you're back in Edmonton...a good resource is The Bike Shoppe (SE, just south of SHWD PK freeway, and east of 50/66/Gretzky), if you're not aware of them. Great guys that will dispense advice, and if you need work done, keep you informed at every step. Nice to have an independent shop that isn't a boutique dealership!

Thanks! Do you know about the motosocial? It’s a motorcycle meetup that happens every month of the summer (Thursday is the last one this year at ace coffee roasters).  Maybe I’ll see you or the bike shoppe people there!


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Offline rusty2078

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Re: 1978 cb550 FKR Mutt
« Reply #57 on: September 07, 2019, 08:06:24 PM »
Hi CW, I haven't heard of it, but I also don't get out a whole lot (a bit too much life stuff at the moment), and am not really active with any motorcycle groups. I am a member (not really active within the group) of the Noral (Northern Alberta) chapter of the Canadian Vintage Motorcycle Group. Apparently it's one of the larger chapters in Canada, and very active.

Offline cwchan

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1978 cb550 FKR Mutt
« Reply #58 on: September 09, 2019, 09:36:36 PM »
More tuning... here’s an image of me getting my float height.  I kept getting varying reading with the clear tube method (maybe some air leaking into the tube). There is an angle because I lowered the front end.  In this picture the bike is also on the centre stand



I found the the pilot screw spring on carb 4 is too short.  Back when I was in Ontario I dropped off the carbs at Sirius consolidated for their carb service... what garbage.... back then I was too naive to know. They even put the wrong main jets in. Just a complete waste of money.


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« Last Edit: September 10, 2019, 09:54:02 AM by cwchan »

Offline Scott S

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Re: 1978 cb550 FKR Mutt
« Reply #59 on: September 10, 2019, 07:19:37 AM »
 That's a pretty ingenious way of checking fuel level.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline cwchan

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1978 cb550 FKR Mutt
« Reply #60 on: September 14, 2019, 05:29:34 PM »
That's a pretty ingenious way of checking fuel level.

Thanks... it’s important to get the bottle positioned so that the float doesn’t hit the side of the bottle as the fuel level rises. Maybe find a square shaped bottle (Fiji bottles?)

More tuning... I bumped up to 95 main jets from the 88s that Sirius installed... it was definitely running lean..got screw set 16016-kcy-670 and installed with the proper spring along with O-ring and washer. INSTANTANEOUS CHANGE!  It idles way better ... revs up and falls back to 1000 quickly... but...

I rode around and then pulled the plugs and #2 is running rich (black) while the rest look slightly rich but good (darker brown)... maybe I’ll resync the carbs but I’m suspecting the jet needles may not be at the same groove... maybe I’ll recheck the valves


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« Last Edit: September 25, 2019, 09:22:57 AM by cwchan »

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #61 on: September 22, 2019, 07:52:18 PM »


Just had a nice ride. There won’t be many more weekends like this


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Offline rusty2078

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Re: 1978 cb550 FKR Mutt
« Reply #62 on: September 22, 2019, 08:38:36 PM »
Nice shot! North side of the river valley and looking towards the east, correct?? Glad the last couple of weeks have been a bit better for riding...calling for snow towards Friday already...

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #63 on: July 05, 2020, 06:54:48 PM »
Dyna S failed.  I switched back to points.  The bike had a Dyna S when i bought it.  I was apprehensive about points after every one says what a pain they are.  I honestly didn't find it that hard to get them properly set and timed.

Offline low-side

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Re: 1978 cb550 FKR Mutt
« Reply #64 on: July 07, 2020, 12:26:41 PM »
It's not really difficult to set and time, it's that you have to do it relatively frequently.  If you want something really reliable, pair your new points with a Hondaman ignition.  You won't have to mess with your points for years.  Nice bike.

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #65 on: July 19, 2020, 05:03:12 PM »
FML... maybe it wasn't the dyna S.  I think its electrical...something is failing and its progressively getting worse.

I just drive around like normal... then i loose power (lights stay on though)... i can't tells if i loose a few cylinders first.  I pull over for a short period, then it starts up again and runs like normal.

I have an electronic tach wired into the 2-3 coil and i get some funky RPM readings while the engine is dying out...
« Last Edit: July 19, 2020, 05:20:24 PM by cwchan »

Offline iron_worker

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Re: 1978 cb550 FKR Mutt
« Reply #66 on: July 20, 2020, 12:55:32 PM »
Possibly a weak coil that is going in and out with heat. That or maybe a condenser? Just spitballin a little bit.

IW

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #67 on: September 08, 2020, 10:06:37 AM »
FML... maybe it wasn't the dyna S.  I think its electrical...something is failing and its progressively getting worse.

I just drive around like normal... then i loose power (lights stay on though)... i can't tells if i loose a few cylinders first.  I pull over for a short period, then it starts up again and runs like normal.

I have an electronic tach wired into the 2-3 coil and i get some funky RPM readings while the engine is dying out...

I'm pretty sure i was just some dirty bullet connectors.  I cleaned them up with steel wool and everything seems to be working well now

UPDATE:  Not the dirty bullet connectors....I looked at the electrical diagram and saw that the starter button affects the ignition circuit.  I opened it up and sprayed alot of contact cleaner.  It did seem that it was quite dirty....but it wasn't that either.... to be continued...
« Last Edit: September 25, 2020, 03:40:05 PM by cwchan »

Offline cwchan

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1978 cb550 FKR Mutt
« Reply #68 on: November 11, 2020, 07:30:02 PM »
I just thought I’d post my rake and trail calcs I did for my fork conversion.  I was cleaning up some paper work and came across it.




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« Last Edit: March 30, 2021, 10:28:20 AM by cwchan »

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #69 on: March 22, 2021, 03:32:04 PM »
Installed these headlight brackets to replace the pipeclamp & sheet aluminum that I was using.

I drilled out the holes from 8mm to accept the the 10mm indicator.




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« Last Edit: March 22, 2021, 03:36:03 PM by cwchan »

Offline Jimcg

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Re: 1978 cb550 FKR Mutt
« Reply #70 on: March 23, 2021, 12:56:30 AM »
Installed these headlight brackets to replace the pipeclamp & sheet aluminum that I was using.

I drilled out the holes from 8mm to accept the the 10mm indicator.




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And...  :)

Very nice looking parts but how does the bike look with them on?

/Jim
1982 CB650Z RC03 owner in Eskilstuna, Sweden

About my bike:
http://forums.sohc4.net/index.php/topic,183848.0.html

Just the pictures and no text:
https://www.flickr.com/photos/189154615@N04/?

Offline cwchan

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Re: 1978 cb550 FKR Mutt
« Reply #71 on: March 27, 2021, 03:27:43 PM »
Heheh



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Offline Jimcg

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Re: 1978 cb550 FKR Mutt
« Reply #72 on: March 27, 2021, 11:17:20 PM »
Heheh



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That looks very good! Strange, I've looked at and admired your bike many times and never noticed that headlight bracket but the new one goes much better along with the rest of the bike. Good example of small things making big difference in overall appearance.

/Jim
1982 CB650Z RC03 owner in Eskilstuna, Sweden

About my bike:
http://forums.sohc4.net/index.php/topic,183848.0.html

Just the pictures and no text:
https://www.flickr.com/photos/189154615@N04/?