Mike's CB550 Project

[Bryanj]

Its a CB550'76 550 FOUR  according to the  I D book making it a K2

[Mike_Berkshire]

Thanks Bryan!

[Mike_Berkshire]

Having completed the front end of the bike I am thinking about what comes next. I’m planning on refitting the rear wheel so i have a rolling chassis as I don’t have a lift and the bike shed is very cramped so it will make it easier to move about. I was going to start on the engine next. The bottom end is staying together and everything above has been stripped down. As I build it up again I was going to start by repainting the bottom end and then putting it in the frame; building upwards from there.does this make sense or is it better to build up more/all of the engine before getting it into the frame?

[Bryanj]

Depends how strong you feel, putting in just the bottom end is far less physical BUT then you have to bend over to do the rest.

Your back

Your aches

Your choice

[McCabe-Thiele (Ted)]

I put the engine in without block etc more awkward than overly heavy. My brother helped with the lifting. Then built up from there. I do have a bike ramp.

[Mike_Berkshire]

Thanks guys. As there don’t seem to be any mechanical issues (apart from my back) I will put the bottom end in first. I’m some way off that yet mind!

[Mike_Berkshire]

Hi all, progress has been slow but there has been progress. At my rate of work I think I am 3 weeks or so away from putting the top end back together. I have been through the plastic bags and boxes of bits to check out the parts Im going to need next and the rear cam chain tensioner mechanism has resurfaced. When I was stripping the top end I had a problem removing it from the barrels as the tensioner adjuster nut on the outside of the barrels had been done up super tight and the screwdriver slot in the central threaded adjuster (M6?) had been broken away on one side.

Im guessing this isn't uncommon and I wondered if there are any fixes other than paying DS £200 plus postage for a 'new one'? Please let me know if there are and what to do.

From reading some of the replies I got when I first mentioned the damage I got the impression that a way of dealing with this is: compress the adjuster whilst fitting it to the barrels and holding it against the camchain tunnel wall where the adjuster pokes through, tighten the nut (above washer and O ring) to retain it in the compressed position, refit barrels, head, camchain, set cam timing etc and when all together release the adjuster nut to allow the tensioner to tension the chain and nip it up in that position. Again, any thoughts on this approach would be very much appreciated.

Mike

[Johnny4428]

Would there be enough of the m6 threaded part to tidy up the end and cut a new slot in the end?

[Mike_Berkshire]

Thanks Johnny; from recollection (when I was stripping it down) I don't think so but I can check once the paint on the barrels has dried and see how much protrudes; that would be ideal.

[Bryanj]

There is no properrepair except replacement, all500 and 550 fours are the same, the adjusting method you wrote is fine as long as the nut spins freely on the thread, you are not supposed to use the slot for adjustment anyway.
Before you fit the assembly i suggest you check that the teeth on the rack and bolt engage properly as forcing the crew can spread the main side plates and you loose proper tooth engagement or even damage teeth

[Mike_Berkshire]

Thanks Bryan. Mechanically it seems to work fine. I assume that the slot is there to hold the mechanism still as you do the locking nut up; is that right?

[DomP]

That's how I understand it Mike

[Bryanj]

Yes, but as long as the nut is not binding it should be ok

[Mike_Berkshire]

Thanks Bryan. When I’m putting it back together I will run a tap through the nut and a die over the thread and clean in solvent/petrol and give a light lube with something?

[Mike_Berkshire]

I’m collecting all the bits ready for putting the top end back together next weekend provided the gasket set arrives and I can sort any necessary replacements for the O rings. I’m a bit anxious as this is the first time I have worked on any motor with more than 2 cylinders, 1 carb and an overhead cam instead of pushrods. However with the benefit of all the info on this forum, YouTube, the parts books etc I think I know what to do.

One question and I’m  sure there will be more is about the oil control valves in the block that mate with the barrels. Should I clean these, blow them out with an airline or something? I’m a bit wary of doing anything as the parts book describes them as valves and so may have small moving parts inside. What prep, if any, is sensible for these parts?