Doms CB550F1 project

[Trigger]

I quite like the idea of a bit of cam reprofiling, if I find everything else to be in good order I may go down that route.  In terms of top end gasket and o-ring kits, where is best to get them?

Vesrah are a top kit and you will need more than a top end set 

[DomP]

I've got it stripped down and barrels off, I think at this point pictures will speak a thousand words, some good, some not so.  Here goes, I've not got a valve spring compressor so that bit will have to wait.

[DomP]

There's more

[DomP]

Apologies for the picture heavy content!

Cylinder 4, the small end bearing has some wiggle but the rest all seem fine from my very basic checks, all piston rings were free but the barrels don't look great do they?

[DomP]

Things I've noticed are the pitting on 3x tappet adjuster screws, some rough and raised edges on two of the puck recesses, pitting to the valve side of the head, the bores are a little scored and one has an inclusion or something.

[Trigger]

Looks like your in for a long winter getting that back to top condition. Tappets are cheap but, I can see where they have chipped away at the top of the valves.
Cam lobes don't look good and it will need a rebore with oversize piston kit at 0.50 or more 
Cam chain guides look like any old guides and you always replace them.

[DomP]

It's just the one lobe not that that makes things better, it's all doable I presume though and there's really no rush on my part.  Would I be best asking one of you to do any machining I need doing or look for somewhere near me and I'll need to as you all for advice on what a rebore entails such as new pistons etc.   Don't get me wrong when I say this but I'm looking to make it reliable and doing what's necessary but not spending where I don't need to. 

[Trigger]

Bryan J is close to you and he has a boring bar, knows the spec and knows were he can get a piston kit from 

[Oddjob]

What's the barrel itself like Dom, any chipped fins etc. I'm thinking maybe replace the liners and rebore those so you can say just do an 0.25 overbore and save the rest for later, if ever.

Oversize pistons available at Cruzinimage pretty cheap and they seem ok from reports. Maybe check to see what the barrels clear up at before ordering. Either with new liners or with the old ones.

I may have some tappet adjusters. The valves with the damage may be able to be dressed up.

Got to say some of the rings look stuck in the grooves in a couple of the pics. Clearly 3 and 4 were not running well.

Head looks ok, camshaft journals not too bad. Rocker box is 550.

One thing I did notice, there appear to be springs fitted against the rocker arms, the 400 got similar but not the 550 to the best of my knowledge.

The camchain tensioner doesn't look bad, maybe check it's moves freely and replace the slipper if it does. The metal part should look straight from top to bottom, most seem to have a bend in them from bad fitting when amatuers take them apart. Check it's straight.
The camchain guide looks normal TBH, I've never replaced one of those unless it was damaged, usually bent.

With the state of the engine, clearly due to badly contaminated oil, I'm sort of dreading what the cranks shells are going to look like. Let's hope I'm wrong and they are fine.

[DomP]

Thanks Trigger, I'll send Bryan a pm.

Ken, the barrels have a couple of bits of fin damage but pretty inconspicuous and ill be painting it if all goes to plan.  Your correct there are springs on the rockers, should they not be there?  Very small marks to two valves but I've also noticed a chip on the cm chain adjuster retaining bolt hole.

No stuck ppiston rings Ken, they are all free but thats immaterial i guess what with the bore wear, tensioner looks OK for straightness too. You're all suggesting I split the cases then, I'm dreading that bit, I can't get the kickstart off the splines for a start😫

[Bryanj]

Recently i have had a lot of my old barrels not clean at 0.25 as the liners have been egg shaped, so worth checking bore before ordering pistons.
You can call me on 07795162623 Monday to Thursday inclusive after 8pm when i am at work driving

[Oddjob]

Remove the pinch bolt on the kickstarter and force a screwdriver or a chisel into the slot, that should expand the slot and allow the arm to come off.

[DomP]

Remove the pinch bolt on the kickstarter and force a screwdriver or a chisel into the slot, that should expand the slot and allow the arm to come off.

I tried that Ken, I'll be a bit more gung-ho!

[Trigger]

Recently i have had a lot of my old barrels not clean at 0.25 as the liners have been egg shaped, so worth checking bore before ordering pistons.
You can call me on 07795162623 Monday to Thursday inclusive after 8pm when i am at work driving

It is one of the mistakes that a lot of owners buy pistons at .25 and only 10% ever do clean up mate. 

[Bryanj]

Yup, im finding them barrell shaped, fine at top and bottom but dont touch in middle, never found a step at the top yet though