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Re: Lost piston ring peg
Posted: Tue Nov 24, 2015 7:59 pm
by Jazzy
Assumption is the mother of all f#$k ups
Looking at the pics there does seem to be some wear at the bottom of the exhaust port.
Re: Lost piston ring peg
Posted: Tue Nov 24, 2015 8:49 pm
by eden
that's not ware that's f@@ked from the ring catching on the way down too!
Re: Lost piston ring peg
Posted: Tue Nov 24, 2015 8:53 pm
by Adam_Winstone
Has the barrel had any work done to it? I've seen lots of ring failures recently as a result of people going too wide/high in the quest for better BHP figures. In those cases people often look to blame the ring or the piston, when it is the porting work that has caused the issue.
Re: Lost piston ring peg
Posted: Tue Nov 24, 2015 8:57 pm
by lambro
Hi,
I didn't build or have any imput in this, I was just the recovery/diagnosis guy.
The kit was a standard unworked top end though, and Martin asked how old, I spoke to my mate and he reckoned about a year old/1000 miles.
The scooter has now been removed from me and back to the original builder as he wants to take up the dealing with MB and repairs after.
Shaun.
Re: Lost piston ring peg
Posted: Wed Nov 25, 2015 8:22 am
by lammydave
I know of two kits with this issue, one is timbos', as mentioned, the other is a 195 version that a mate of mine had.... I'm sticking with mugellos from now on....
Re: Lost piston ring peg
Posted: Thu Nov 26, 2015 10:37 pm
by Toot-oasc
lambro wrote:The scooter has now been removed from me and back to the original builder as he wants to take up the dealing with MB and repairs after.
Best of luck, if it's anything like my own dealings with that dealer after my piston dropped a ring pen (and I found out that that make of piston, from that same dealer, has a history of this particular fault), the reply I got was: Quote "We can't be with you at every garage to make sure you correctly mix your petrol and oil"
Re: Lost piston ring peg
Posted: Thu Nov 26, 2015 11:21 pm
by Evesy
I've had two MB Pistons do this to me. Bottom peg dropped out on both of them ring spun round and wrecked my imola kits. I thought I was just unlucky on the first one but was fuming when the second happened. MB sells some quality gear but these Pistons are garbage. I'm not the only one it's happened to my mates RT195 kit piston did the same. Wasn't impressed with the customer service to be honest. I sent the second imola kit to him as he wanted to inspect it. I was given some bull about the kit being crap and wasn't the Pistons fault. The problem was everything from the oil to the melting ice caps but Defo not the pin coming out. Got sent the RT kit as I was persuaded that it was better than the imola. I thought I'd give it a go. Didn't like it sold it to my mate and that was the one that failed. Won't stop me buying parts as I said some are quality bits but the Pistons no thanks.
Re: Lost piston ring peg
Posted: Thu Nov 26, 2015 11:47 pm
by ulyssescale
I've got a little over 3,000 miles on an Mbgm RT225 kit with no issues. I've also got a couple RT pistons in modified GP iron barrels - one of them has over 11,000 miles on it. Before everyone goes Chicken Little consider that there is a long history of established manufacturers/designers with products that have had some documented failures.
You've got a kit that had a failure? I've got one that hasn't.
Re: Lost piston ring peg
Posted: Thu Nov 26, 2015 11:59 pm
by eden
Decent pistons handle pegs dropping out much better than other pistons.
This just needed a new piston and has done many miles since

barrel and bore being iron had little damage.

Re: Lost piston ring peg
Posted: Fri Nov 27, 2015 11:47 am
by GeorgeS
Whilst these sort of reports are concerning (as I'm interested in the RT225/230 kit myself), I keep reminding myself that bad news always travels further & faster than good and for each person who's had a failure there'll hopefully be dozens who haven't.
Surely all kits kill experience failures from time-to-time, but could you say if these are any worse or better than others? Everyone has their own way of doing things, can the way a kit is assembled contribute to it's failure?
All the best,
George.