RB22 After Germany

[KCB]

It was a racetour. Been sent back for examination, and yes I did get the quote "oh I've never seen or heard of that before".

Can you sort of show with a diagram or something the chamfering of the ring gap, I don't really want this happening again !!!

[matthew]

I had a racetour piston drop a ring peg on me last year, seized my TS1 on the way to Woolacombe, when I got the bike back home I stripped the top end and when I took to rings off the piston the ring peg just fell out, it was only the rings that were still holding the peg in the piston

[Rude De]

Your second picture has a shinny polished spot, on the edge crown going down the side and over the side towards the skirt side where the ring groves are, with no carbon build up. It should match up to a place on the head where it was hitting the head the squish and the edge of the combustion chamber were hitting the piston. :ninja:
Take a picture of the head. :baddevil:

[KCB]

Your second picture has a shinny polished spot, on the edge crown going down the side and over the side towards the skirt side where the ring groves are, with no carbon build up. It should match up to a place on the head where it was hitting the head the squish and the edge of the combustion chamber were hitting the piston. :ninja:
Take a picture of the head. :baddevil:

Nope, I think you are wrong there, check out the head where the pin has left indentations. They get shallower as it gets to that side of the piston head showing that if anything there was more clearance that side of the piston than the other.

Plus I don't think it would have lasted over 1000 miles if the squish was too small !! And I might of noticed some sort of noise as well ?

[Bufficus]

It was a racetour. Been sent back for examination, and yes I did get the quote "oh I've never seen or heard of that before".

I've had a Race Tour piston top ring issue lately. A 2K mile piston top ring peg wore or dropped to 0.5mm. Not enough to stop the top ring spinning. Luckily I noticed this after an annual check and rebuild.

I was not impressed after only 2K. MB replaced the piston at cost + discount. I expected a replacement.

I accepted because of limited options. Having spoken to others I know this is not uncommon.

PS. My piston had not been getting hot. As verified by the underside of the piston.
Also, I'm not blaming anyone, just want to know what's happening.

[GP Kevo]

According to MB, piston rings can wear during running in and excessive ring gap is causing the rings to hammer the ring peg (if my memory about our converstation is correct - and my technical knowledge about this stuff is limited). They advised me to check the ring gap at 1,000 miles and replace the rings if the gap is excessive. This was after my TS1 with RaceTour piston dropped a ring peg and the ring caught the exhaust port and did a fair amount of damage which I had repaired and had some extra porting done, with new RaceTour piston. Now I'm checking ring end gap often and I have spare sets of new rings so I don't have to order them if / when needed.

[shocky]

So when you buy a brand new motorcycle one of the things checked at its first service is the ring gap?

I think not

i strip mt GTS every week dont you know ............ok not really
TBH ive never really over checked any ring gap (once when putting it together has always been enough esp when working at Cotswold motocycles) and having done a far amount of jap piston conversions on vespas and lammys plus scores of other top ends for myself and others on many small 2T,s sometimes "bodging" the next oversize rings onto a smaller piston after some work with a swiss file because the bore has some wear ive never had a ring peg let loose or even any wear in that area that i noticed but like i said i never checked never realising this could be a problem area ........ im beginning to wonder if these problems of late are something to do with the horizontal orientation of the cylinder/piston/crank

[leigh]

If it was anything to do with the orientation of cylinder/ crank etc. Then surely ring pegs coming out would have been a problem from day one.

Leigh

[shocky]

If it was anything to do with the orientation of cylinder/ crank etc. Then surely ring pegs coming out would have been a problem from day one.

Leigh

yea good point bit of a bum steer really its that i was chatting to a ex ducati work mechanic about stuff and it was a suggestion on his he explained about diagonal lateral forces and stuff

[leigh]

Could just be a bad batch. Still not good mind.