RB22 After Germany

[GP Kevo]

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

I'm supposed to strip and check my Aprilia RS 250 often, and my local shop (that knows and loves 2 strokes) advises me, because of the poor fuel these days, to check the ring end gaps every 1,000 miles. Don't even get me started about the exhaust power valves.

On my TS1 I've had pretty bad luck with piston rings. The genuine Yamaha IT 175 piston on my TS1 200 lost the ring peg, ring spun and caught on exhaust port with disasterous results. That happened twice. Then the cylinder went to MB for an overbore, porting, and an early RaceTour piston. At about 1,000 miles the top ring peg sunk in, ring spun and caught on the exhaust port with same disasterous result. That went back for repair and more porting and new RaceTour piston, so far, so good.

My Annihilator hasn't had any ring problems but the fuel is different in the USA.

A Vespa GTS is a poor analogy.

[GP Kevo]

I've done only 900 miles on the RS, which is in storage but I'll have to strip and check it when I'm settled and have my bikes in one place. So I don't know what I'll find but I'd expect normal wear, but if there's excessive ring wear isn't it better to catch that on an inspection rather than on the road? The power valves are known to wear quickly and those you definately don't want falling apart on a ride out.

As for the TS1 you can bet that I'm now paranoid about the rings after 3 occurances. I've already checked it once at only 600 miles and end gap was good. I'll check it again at 1,000. MB did say that excessive wear may be occurring during running in, hence the 1,000 mile end gap check and ring replacement if neccessary. It's my local motorcycle shop owner that told be to check rings every 1,000 miles on the Aprilia. He does the same with his Suzuki GT 750. He blames the crap petrol they have in Ireland.

The Humiliator / Annihilator was already run in and had a good number of miles on it when I bought it. I've only thrashed it and haven't measured the ring end gap.

[shocky]

yea i know the GTS was a poor comparison but its all i have at the mo
what reason were you given that the rings had to be checked every 100 miles does the crap fuel wear rings through lack of lubrication or is there another problem? i know ethanol has caused problems with BMW engines mainly in the US causing cylinder wear due to nicasil breakdown !
i know the RS,S ARE FINE MACHINES BUT NEED LOOKING AFTER AND ARE HIGH MAINTENANCE SAY COMPARED TO 4T
I GUESS PEOPLE WHO OWN AND RIDE HIGHPOWER MAINTANANCE CRITICAL LAMBRETTAS ARE ARE EXPECTING A LITTLE TO MUCH FROM THERE MACHINES IF THEY EXPECT TO BE ABLE TO TOUR THE UK FOR SEVERAL SEASONS WITHOUT EVEN TAKING THE TOP END OFF FOR A LOOK .PERHAPS PEOPLE WHO SUPPLY THESE KITS SHOULD AS HAS ALREADY BEEN MENTIONED PROVIDE A STRICT SERVICE/INSPECTION SCHEDULE AND EXPLAIN THAT THESE KITS REALLY ARE DESIGNED FOR THE TRACK !

[dirtyhandslopez]

personaly i strip and rebuild my engine at least twice a year, i have always replaced the piston every winter. I've always done this because i used to use asso pistons and always saw hair line cracks on the inlet skirts, in the three years ive been using wiseco pistons ive changed the piston each winter so i could try different inlet timing, as yet ive seen no excessive ring ware, no ring peg problems and no hair line cracks on the skirts on any of the wiseco pistons.

I've yet to see a Wiseco go bad. I did have one where I burnt the rings up in 175 miles on the way to a rally. My own fault for hanging with the Vespa's and going to slow with to much oil. Carbon built up under the rings, pushing the rings into the cylinder where they got eaten.
I think if you get a year on a set of rings, running balls out all the time without a filter, you are doing well.

I think the check the rings after breaking part is because in first starting up and running the scoot, the cylinder smooths out, ie the hone mark start to disappear through wear, and that is when the excessive ring gap comes into play. New set of rings, a quick hand hone with some 1500 and off you go.

[KCB]

Well, I am pleased to say the outcome of this is fantastic.

MB are going to replace not only the piston but also my barrel completely free of charge.

I have been emailing Mark periodically with reference to this piston issue, and I can honestly say he has been nothing but friendly and helpful.

I can only say that MB's customer service and support have been second to none with regards to this issue and I can't praise them highly enough.

Obviously there will be people who will say "well done MB" and on the other hand their will be those that say "quite right too!" as the piston seems to have caused the issue.

Well my view is that this is what customer service is all about and well done MB. Mark sent my piston to his piston guy for examination and this is what he said after the results came back:

"I guess this is a freebee, it is rare a peg actually comes out, maybe two or three in a thousand, but it is a little more common for rings to wear, move over the pins and loosen them, then they spin and cause major damage in an alloy cylinder. This is not the case with your piston."

He fairly and squarely held up his hands and has rectified the situation in a very responsible and positive way, well done Mark and MB.

Cheers,

Kevin.