what piston ?

[rbgaz]

hi all need a new piston for my rb, but which one do i buy the mb site has a million diffrent ones

which is better the ones with ceramic plated ? one piston ring or two ? what dos a b c d grades stand for ?

ive a 60mm af crank in it

p.s scoot was still running after about 6000 miles but was rattling and not lot of comp so thought id hav a look and cant belive it was still running as piston is fooked would like to post a pic but cant unless someone who can will let me send a pic to thier moby

[fred]

what cc is it? the a,b,c etc is which grade of piston. It should have a letter stamped on barrel somewhere.

[soullad]

hi all need a new piston for my rb, but which one do i buy the mb site has a million diffrent ones

which is better the ones with ceramic plated ? one piston ring or two ? what dos a b c d grades stand for ?

ive a 60mm af crank in it

p.s scoot was still running after about 6000 miles but was rattling and not lot of comp so thought id hav a look and cant belive it was still running as piston is fooked would like to post a pic but cant unless someone who can will let me send a pic to thier moby

Won't AF replace it?

[fred]

to be honest if you've run a tuned lamby for 6000 miles without having top end off,then you've done rather well.
I try to change rings every 1 - 1.5k miles.Altho' i do run open mouth carb.
Has a ring peg fallen out?,if so,it may be due to excessive ring wear.

[rbgaz]

hi mine is run without filter also, its the 225 rb one ring was stuck in and top was coverd in bad carbon layer,also lump out by the exhaust port were it looks like it nearly blow hole and lots wear by the ring ports barrel looks fineish, it was a mb racetour piston 70mm reason i dont no which to buy is because theres a lot of 70mm pistons on there site

[shocky]

surely its best to ring them ? im told there very helpfull and with required to some people having issues with there pistons they will be able to advise on how to fit and run them

[eibargum]

By the sound of it you,ll need to repair the exhaust port, then buy a new piston, have the barral re-plated to match the piston, you might as well have it matched to a A grade, all in all alot of time [lancourts took over 5 weeks to plate mine] and money. If i were you i,d proberbly buy another new RB kit [other kits are availible] and strip it down every winter for a check, and sell your old barral to someone that wants to do some further work on the barral.

[rbgaz]

took it to my local tuner today and he said barrel is fine, but there is no rb pistons in the country for time being gooner b about 5 week wait !! so we are going for the new super monza 70mm piston with reprofiled head

[soullad]

Thing is, you need to find out why the piston has failed?
If you think it was just an inferior product then surely AF need to know about it and be prepared to replace?
If you think something was amiss top end then find out what caused it and put it right?

Just trying to save you some dosh fella.....

[eibargum]

Thing is, you need to find out why the piston has failed?
If you think it was just an inferior product then surely AF need to know about it and be prepared to replace?
If you think something was amiss top end then find out what caused it and put it right?

Just trying to save you some dosh fella.....

He says it was a MB race tour piston so no good going back to AF. rbgaz, did you keep the asso piston that came with the kit, couldnt you use that, or do you have a mate with a used piston to get you back on the road, i flogged a mate an little used asso B grade last night for £40 to get him back on the road.