That sounds just like mine and I've been told it's the top end and would be best swapping the piston while I'm on! But I'm really not keen on pulling the engine to bits!

Any tips?

Hey Lewis, its a simple job, the top end has to come of but its a very easy job, exhaust off, carb and reeds off, then its a couple of engine mounts and the main bolt through the swing arm

drop the engine out, 6 bolts on the head and 4 on the barrel, slide off then unclip the old piston and rebuild

simples

You won't know what you need until you have the bore measured, may need a replate.

For bits try Sandifords or you may get pattern (or genuine) parts cheaper from an Apico dealer.

Alright cool, I'll see how I get on cheers.

Took mine to bits last night super simple took the radiator out and some wires and moved them to one side and pulled the barrel off! Piston and bearing were pretty beat up but the barrel look sound!

Order the kit today from JimSandifords so will let you know if it goes back together as easy as it was to came apart haha

Took mine to bits last night super simple took the radiator out and some wires and moved them to one side and pulled the barrel off! Piston and bearing were pretty beat up but the barrel look sound!

Order the kit today from JimSandifords so will let you know if it goes back together as easy as it was to came apart haha

Awesome, nice one.

Have you got any pics? Just interesting to see it in bits!

Awesome, nice one.

Have you got any pics? Just interesting to see it in bits!

Will take some tonight mate

If it goes back together as easy as it came apart its a couple f hours work to do the whole thing!

Awesome, nice one.

Have you got any pics? Just interesting to see it in bits!

Here's some pictures I'm still waiting on the top end kit to turn up!

Here's some pictures I'm still waiting on the top end kit to turn up!

Looks good, tidy bike as well. A lot cleaner than mine!

Quite a bit of room to work with as well which is good to know.

Do I spy a Beta Techno in the background?

Cheers, good luck with the refit

Edited November 7, 201411 yr by 331sam331

I had the exact same issue with mine, the main bearings were completely shot, bought everything from feet up I think it cost about £350-£400 including new barre.l

So I whipped the head and barrel off today. All looks very good. Definitely play in the little end and the piston noticeably rocked in the barrel (at TDC).

Now there is no letter on the piston for A, B or C but the barrel says A so should I put a B piston in? The piston lining has a very very slight lip at thebbottom and top.

I would like to put the B piston in if it will improve sound and longevity.

Here is a picture of the piston ring gap.

Obviously I am worried if I go up a size in the piston I could break a ring and wreck everything...

Here is a picture of the piston.

And the barrel

Thanks guys!

Bump.

this was my engine when i took the side casing off,

i had the same issues when i rebuilt my monty motor, i bought a complete piston and barrel kit from feetup trials and it wasnt expensive, he does the barrels on an exchange basis, so take or post your barrel with piton to him and he will exchange it for a new/replated barrel with new piston, rings and small end with gaskets and anything else you may need for the build.

if you need any advice on building give me a pm im more than happy to help you out where ever possible.

i had the same issues when i rebuilt my monty motor, i bought a complete piston and barrel kit from feetup trials and it wasnt expensive, he does the barrels on an exchange basis, so take or post your barrel with piton to him and he will exchange it for a new/replated barrel with new piston, rings and small end with gaskets and anything else you may need for the build.

if you need any advice on building give me a pm im more than happy to help you out where ever possible.

Thanks, I really can't afford a barrel as well though. Plus it looks like mine has been pretty well looked after and I don't see any wear on the barrel.

I have had a look around on other forums and they are saying that the difference between A B and C pistons is very small. My thinking is that any wear on the barrel will be compensated by a very slightly larger piston. On the other hand, I don't want to go ahead and cause any damage.

I may just end up getting an A piston and given that the main source of the noise was little end wear I hope it will cure the noise.

Cheers for the reply

Right, just been on the phone to Sandifords who sell the piston kit, and looks like the only option is an "A" piston and putting any larger piston in the barell is a big no no.

Glad I rang because I was going to buy a "B" piston.

Will keep this updated and hopefully an after video next week with a nice quiet engine!

Betarich, That is the worst I have ever heard. Quite obviously a victim of the silly trend in thinking

that a 2 stroke runs so much better without oil.

Have a nice day.

Larry