Partially Restored 74 CB550

[davidcumbria]

Fitted the barells  today and when pushed as far down as possible they rockslightly  on the restrictor valves that act as seating dowels. Tried tapping down quite hard with mallet and wood protector but it still doesn't seat flush see photo.id yhis as expected and will it pull down with the cylinder head nuts. Right now if would leak like a sieve.

[Nurse Julie]

Are you sure you have the restrictor jets in the right way up?

[davidcumbria]

Had a look at parts diagram and it looks like the larger diameter end fits into the engine case in which case you are spot on Julie - they are upside down. Will try again tommorow - so glad I checked before trying to fit cylinder head.

[Nurse Julie]

Had a look at parts diagram and it looks like the larger diameter end fits into the engine case in which case you are spot on Julie - they are upside down. Will try again tommorow - so glad I checked before trying to fit cylinder head.

Great, that's an easy fix the.

[davidcumbria]

Definitely upside down have seen a photo in the magazine engine  rebuild article - which btw us very useful. Great remote diagnosing Julie 👍

[Oddjob]

Check the bottom of the camchain tensioner is located in the slot in the lower crankcase whilst it's like that. After, push the tensioner blade in by hand until it won't go any further and lock it off with the locknut.
Missing the dowel in the clutch case opening near the primary shaft gear. Needs to be there for the gasket to locate properly. Should be 2 of them in total.

[davidcumbria]

Will do Ken. Have got the dowel bagged for refitting and was meticulous in seeing the the tensioner and guide were correctly located using the good advice on here. I’m a bit disappointed by the stiffness of the new cms aftermarket tensioner . It seems weaker than the banana shaped original I replaced due to cracks forming near the location lugs.

[Oddjob]

I thought the same when I compared a DS one with a new original

[davidcumbria]

So I wasn’t being completely daft fitting the restrictors upside down since that’s how they were when I stripped the engine.per an earlier question  Now I know why they were so difficult to remove - because they had been pressed in when tightening cylinder head down.

When I lifted the barrels slightly and replaced the restrictors in the corrrct orientation to my dismay the barrels still wouldn’t seat on them. Barrels off revealed the in correct fitmen had scuffed up the drillings  in the barrel restricting the width. .
Got barrels on my pillar drill and removed the galling, cleaned up meticulously, and finally the barrels slid down into place correctly.

The blockage of the restrictors by sealant was also  responsible for the dry top end when I first ran the bike. All in all I feel these little things are having a vendetta with me. At least having had the barrels on and off about 4 times. I’m getting good at it !

[davidcumbria]

So engine out , stripped, repainted, rebuilt, back in frame and it’s only at this point I notice that the upper bolt securing the starter motor to the upper case has been snapped off flush with case. Bolt is near horizontal and joint is exposed to weather so no surprise it got rusted in and sheared sometime in last 50years.Skinny bolt with long free run from the head  to where it secures in the case.  Starter is still secured by one bolt and the casing collar and was working ok but I need to at least try to get remains of bolt out for my own acceptable quality level.

I have bought a stud removal kit with left hand drills and extractors. Can’t heat the area as much as I would like due to new paint. Anyone had experience of dealing with same issue ?  Hopefully easier than a sheared stud since it shouldn’t be bottomed out in the thread hole.

[Laverdaroo]

Anti-clockwise  drills on a right angle chuck have always done it for me but always an awful job if your access is restricted. Just go careful and don’t thrash at it. Plus gas penetrant always works well for me also but every one needs a different approach really.

Good luck


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[Oddjob]

Try some heat, seems to work with those dowels.

[davidcumbria]

Success! No damage to engine case threads and no heat needed so paint preserved. The flute type extractor worked a treat after a lot of very careful drilling.

This is what I used.

https://www.amazon.co.uk/dp/B076716GZH?ref=ppx_yo2ov_dt_b_product_details&th=1

The drills are not left handed but worked well at low speed / higher pressure to cut out the Honda bolt. I also used a centre drill to aid starting off centred and lots of rocol lubricant.  No significant torque needed on the extractor I think drilling out most if the thickness of the bolt had weakened its grip.
Thanks for the positive comments. Happy days.

[McCabe-Thiele (Ted)]

Always good when you sort a snapped thread.

[Johnny4428]

Nice work! Very satisfying.