aprilia piston change rotax 123

[john0207]

my bike overheated and i think the head gasket has gone or the piston or the rings have had it( "no compression").

i was going to get an engine from ebay but have decided to just change the piston and gaskets.

it a 1998 rs 125 extrema so i think its a rotax 123 engine i think?

does anybody know how difficult this is or should i let a garage do the work.

i not in any hurry really and would like to give it a go myself if i can

cheers

john

ps thanks to "kickstart" for his help with my other questions about the problem.

[Kickstart]

Hi

At that age it may be a 122 or a 123 engine. Pistons are the same I think.

However it is has seriously overheated then the chances are that it has nipped up, wrecking the rings and the barrel as well as the piston.

A piston can be had for about £80 through Peter Knight (0176 141 4106) (he is a Rotax specialist) or for about 50% more through Aprilia. You can get non Aprilia / Rotax pistons which are of a decent quality but make sure they are from a supplier you trust.

You can get a scored barrel repaired and replated from someone like PJ Engineering in Wolverhampton.

Changing the top end of the engine is not difficult. Just take your time.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[john0207]

[Kickstart]

Hi

If you know roughly what you are doing then you can get away without a manual, but if you have never changed a piston before then one would be a very good idea. Peter Knight can supply a copy of the engine workshop manual.

All the best

keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing