Before I start...

....rebuilding the top ends of the SOBoxer, has anyone got one with a
half-decent engine going cheap for some other reason?

600, 750 or 800...

 

No, but I have a set of R80 piston rings you could have.

Does this mean you'll be coming to Chimay?

 

R80 rings would only work if I had barrels, pistons and heads...

I was balancing up the cost of getting reworked heads and possibly rebore or
new rings and a quick hone, as compared to a s/h engine in half-decent nick.

 

What have you done to it??? :-(

Last time I looked at your web site it was looking fine, complete with
interesting suspension etc.

I've seen a few sets of heads/barrels come up on eBay recently, so you
might get lucky (yer not having mine!). Also try the usual suspects,
esp. Sherlocks, but IIRC exhaust valves are £>40 (which was a nasty
shock), although sleeves were cheap enough and relatively easily fitted.


Regards,

Simonm.

 

it's still running, just smokes like a smokey thing and down on power and
the valve gear is still noisy same as it's been for years.

I know there are problems with rocker shaft bearings on it, and I guess that
the valve guides are worn. Not sure about rings until I strip it, they
might be OK.

It's been due a proper rebuild of the engine top ends for years. Right one
is worse than left.

 

You might be OK with just the guides, if the seats are passable or
grind/lap-able.

When I had mine apart a couple of years ago, they still had the honing
marks visible on the Nikasil (sp?) liners, after 35k miles (at least).
I'm reasonably sure that the RH exhaust valve was more worn than the
left too - I still have the old ones but can't remember which was which.

This seems to be common. Sherlocks mentioned that RH heads fail more
frequently than left ones. I think it's partly because they're higher,
and partly because the bike tips to the left on the stand, thus
fractionally more wear when cold starting (oil drains out of head).

Leastways, it's the only theory I've got to explain it.

Regards,

Simonm.

 

Idiot! Further back - gets hotter. (only one pint of coffee this morning
so far).

Regards,

Simonm.

 

I'm inclined to go for reworked heads, solves everything in one go. Fitting
guides looks to be a pain.

This one has iron liners. Having said that, they were fine last time it was
looked at, some years ago; might get away with a quick hone and some new
rings. I did put rings in it once before, but it might be that it wasn't
honed, or not enough.

I reckon it's the stand thing. Although mine most often parked on the
centre stand.

 

well, I wasn't going to say that...