Scooterotica

Looking for a good quality over sized piston, I think a 66.6 what's the best/ reccomended?

Assuming 58/107 crank I have had nothing but good experience with the MBD RT piston. Have them in two bikes right now and have put a few motors for other together using them (Indian stage 4 and 2 rt top ends). They are expensive compared to others but quality always is.

Whats it going in though? If its a standard ish spec, £140 for a forged piston seems ott.

Just need to look at it this way. Is it cheaper to replace the piston and rebore the cylinder every 1000 odd miles because they skimped with a 3 thick ring circus piston or just pony up the coin and forget about it? I don't know about anyone else but I like to ride much more than I like to turn wrenches (and I really like turning wrenches).

One of my RT pistons is in a SR190 cylinder (stock points, carb and exhaust). Other is in a TV200 restoration. I figure those will be the last pistons I ever have to buy for either of those top ends.

Grumpy225 wrote:Just need to look at it this way. Is it cheaper to replace the piston and rebore the cylinder every 1000 odd miles because they skimped with a 3 thick ring circus piston or just pony up the coin and forget about it? I don't know about anyone else but I like to ride much more than I like to turn wrenches (and I really like turning wrenches).

One of my RT pistons is in a SR190 cylinder (stock points, carb and exhaust). Other is in a TV200 restoration. I figure those will be the last pistons I ever have to buy for either of those top ends.

Lol! 1000 miles. My last poverty thick ring piston did 8k before i decided to replace it.Where did the rebore after a 1000mls come from too?

soosh wrote:Where did the rebore after a 1000mls come from too?

Rapido barrel??

soosh wrote: Lol! 1000 miles. My last poverty thick ring piston did 8k before i decided to replace it.Where did the rebore after a 1000mls come from too?

Ok 1k can be a bit on the short side (unless running a rapido, hole the piston or catch a ring). You have to admit 3 ring pistons are old technology and arn't doing anything to help HP. Modern two strokes are 1 or 2 thin ring pistons. There is a reason for this. Specifically due to longevity, reliability and increased performance. This is exactly what MBD achived with their RT piston.

When in doubt, just look at what Yamaha did. They were the height of production two stroke motor technology.


Timbo asked for an opinion on a quality piston and that's what I suggested.

Grumpy225 wrote:

soosh wrote: Lol! 1000 miles. My last poverty thick ring piston did 8k before i decided to replace it.Where did the rebore after a 1000mls come from too?

Ok 1k can be a bit on the short side (unless running a rapido, hole the piston or catch a ring). You have to admit 3 ring pistons are old technology and arn't doing anything to help HP. Modern two strokes are 1 or 2 thin ring pistons. There is a reason for this. Specifically due to longevity, reliability and increased performance. This is exactly what MBD achived with their RT piston.

When in doubt, just look at what Yamaha did. They were the height of production two stroke motor technology.


Timbo asked for an opinion on a quality piston and that's what I suggested.

True but MB aren't the only ones turning out decent thin (wire) ringed pistons, Matika for instance and they are less than half the price of the Racetour.

Grumpy225 wrote:

soosh wrote: Lol! 1000 miles. My last poverty thick ring piston did 8k before i decided to replace it.Where did the rebore after a 1000mls come from too?

Ok 1k can be a bit on the short side (unless running a rapido, hole the piston or catch a ring). You have to admit 3 ring pistons are old technology and arn't doing anything to help HP. Modern two strokes are 1 or 2 thin ring pistons. There is a reason for this. Specifically due to longevity, reliability and increased performance. This is exactly what MBD achived with their RT piston.

When in doubt, just look at what Yamaha did. They were the height of production two stroke motor technology.


Timbo asked for an opinion on a quality piston and that's what I suggested.

I agree,but lets not confuse a decent Yamaha to a mild Lambretta tune. I only talk from experience,i run a Wiseco in my TS which it probably doesnt really need but my Saxelby stage 4 runs a cleaned up Mahle on the top 2 rings and cost me £65.I always said to myself if it breaks id replace it with a stronger piston but that was yrs ago,i can only assume for that its well up to the job.

Muttley McLadd wrote:

soosh wrote:Where did the rebore after a 1000mls come from too?

Rapido barrel??

Are they that bad? I looked into buying one yrs ago before i got this kit.