SOHC.co.uk Forums > Project Board
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:
--- Quote from: DomP on August 27, 2023, 07:51:02 AM ---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?
--- End quote ---
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.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version