Doms CB550F1 project

[DomP]

Thanks all, I'll have another look at it today, struggling to get a steady idle, carbs set to factory with genuine jets etc and bench synced and the low compression concerned me a bit.  I'll get there, might take me delving into the engine which I've never done before.  Is it that costly to do a DIY top end rebuild?

[Trigger]

A 550K0, 550K1, 550K2, 550F1 brake plate is middle number 374 and was fitted to the 323 hub 
A 550F2, 550K3 brake plate is middle number 341 and was fitted to a 404 hub 

Dom has a 323 hub as he has a CB550F1 UK model   

It is very easy Dom. All you had to do is unplug the hose that runs from the top of the engine breather cover where it attaches to the air box at the bottom. Find a rubber ferrule that would fit over the pipe at the bottom of the air box. This would cap any oil vapour from the engine. Use a 550 air filter with what you already have and hunt for a lid for the air box.   

[Trigger]

Thanks all, I'll have another look at it today, struggling to get a steady idle, carbs set to factory with genuine jets etc and bench synced and the low compression concerned me a bit.  I'll get there, might take me delving into the engine which I've never done before.  Is it that costly to do a DIY top end rebuild?

Cost is down to what you find that needs replacing 

[DomP]

I've just done a compression test again after trying to get it to idle and giving up, a fair amount of smoke and smelling really rich.

New results with all plugs out, and full throttle.  I think I'd left the choke on however.

Cylinder 1 - 125psi
Cylinder 2 - 110
Cylinder 3 - 120
Cylinder 4 - 110

I've turned the mixture screw in so it's now at a full turn out. Next plan is to let it cool down and check/adjust the valve clearances.

[McCabe-Thiele (Ted)]

A lot better than they were previously @ 70,75, 80, 82 ish.

Might be worth putting a few miles on her with some upper cylinder lubricant if it's not run for a while they might improve - nothing to loose.

If it turns out to be a bore/piston wear issue you really need to split the crankcases as new pistons can put extra load on the crank so best to check the big ends & main bearings.

Bryan here does rebores for 500/550's I think as well as Trigger so might be worth a couple of PM's for prices.

[DomP]

It's not roadworthy enough yo put miles on sadly Ted, the rear hub is buggered and I can get it to idle without stalling as yet.  Just done the valve clearances and I think I should check the set up of the Dyna S ignition to be sure it's not set incorrectly.  Not sure how it's set up but I'll do a google

[DomP]

Why isn't there enough adjustment in my electronic ignition?  To set a timing light to come on t the F mark with the advance at full it won't rotate far enough.  I'm a bit stumped

[McCabe-Thiele (Ted)]

You can do the Dyna S like points statically or dynamically.
Okay without going back over your post have you cleaned the carbs & bench synched them?

[Oddjob]

Can't remember which it is now but one electronic ignition is set at full advance. So rev to 4k and set it there and see if that works better

[Trigger]

https://www.google.com/search?q=set+up+a+dyna+cb550&rlz=1C1YTUH_en-GBGB1002GB1002&oq=set+up++a+dyna+cb550&aqs=chrome..69i57j33i160l2.11336j0j7&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:7c85c45c,vid:q7oy8RSB9Vs

[DomP]

Yep carbs are refurbed and synced as close as I could get them.  I think I've been using the wrong mark🤭, it's easy to be set to the very far right mark with the advance at full where as I'd been setting it to the F.

[DomP]

All sorted, still sounds like a bag of nails though and stinking rich😬  I get the feeling it's going to,need open heart surgery.

[Trigger]

 glad you got that one sorted.
You will find you need to strip the whole engine down and be prepared for some surprises 

[Nurse Julie]

Are you turning the air / fuel mix screw the right way?. Out for more air = leaner, in for more fuel = richer.

[DomP]

I've taken a video of it running, not sure it will upload on here but it doesn't sound smooth at all, my xs650 sounds smoother!  When I drop the revs to around 1100 it starts to sound a bit clanky.  I very much doubt that the previous owner had it running and went round the block like he claimed when he last used it, more like he stopped running it due to what I'm hearing.