Scooterotica

Bought a freshly rebuilt engine off a guy a while back and have just got round to jetting the carb and the piston has destroyed itself.
I need to now find a new piston and rings but I don't know for sure what the piston is. The casings are definetely LI , that I know.
He said it was a TV top end, so does that mean it will be a TV175 bored out to 200 or a TV200 with stock 200 piston??
I know it's a long shot but I was hoping to get the right piston ordered before the engine is dropped out of the scooter.
I would like to put a modern piston in if possible, wiseco perhaps or maybe something Japanese??? Any suggestions would be a huge help.

Thanks

Unless the case has been welded up then it's a 175 cylinder. You should pull the cylinder before ordering a piston so you know what size to get (unless you plan on going to 64mm). At miminium just get the head off and aprox measure the bore before ordering.

What makes you think it's a 200? Is the bore 66mm?

What caused the piston to destroy itself?

LI casings will be what's called 'small block' - the cylinder stud spacings are different and an original type 200 cylinder will not fit, unless it has been modified to accept a large block cylinder. This usually involves welding and redrilling the stud holes and opening out the mouth of the casing to accept the larger spigot.

It could be a TV175 top end but the TV used a longer 116mm conrod (as opposed to the standard 107mm) with a completely different piston gudgeon pin height.

There are 175cc conversion pistons available which are designed to fit with the standard rod.

I think you need to properly identify your components then examine your options from there.

Thanks for the fast replies

It has got the longer TV conrod and I am pretty sure from what you guys have described that it will be the TV175 barrel bored out to 200.
Is there a Japanese/Wiseco piston that will fit this set up? A previous engine I had used a TS185 piston but that was with a SR 185 barrel.

Thanks again

If I remember correctly the TS piston is 64mm and has a different piston height again and required shortening the barrel 'top and tail' to get the port timings in the right place.

Unless you can be sure what the bore is now there's no way you can stick your credit card in the Internet and just pick a piston and expect it to fit.

The main conversions uses to be Honda at / around 205 cc on a 67mm piston, but I think these are hard to come by, but MB might now do a RT piston for these. That said I think 67mm is probably a rebore too far IF your barrel is a TV175 taken out to 66mm.

Have a read of this

i personally think you should ask your mate to let you loose on his TS1 for an hour or two then you can tell us what you think ............i`ll bet A fiver you opt fo the TS .........ts1 any day

joeswoonara wrote:i`ll bet A fiver you opt fo the TS .........ts1 any day

Maybe.. but the OP said it's been tuned for touring - ie, they've stopped it revving properly and strangled its performance.

A better bet would be to start from scratch by building an engine for touring, not detuning a revvy barrel.

Muttley McLadd wrote:

joeswoonara wrote:i`ll bet A fiver you opt fo the TS .........ts1 any day

Maybe.. but the OP said it's been tuned for touring - ie, they've stopped it revving properly and strangled its performance.

A better bet would be to start from scratch by building an engine for touring, not detuning a revvy barrel.

Did you two mean to post this in THIS thread?

Yup.. It was very early in the morning..

And it's a small screen

joeswoonara wrote:i personally think you should ask your mate to let you loose on his TS1 for an hour or two then you can tell us what you think ............i`ll bet A fiver you opt fo the TS .........ts1 any day

kin ell.....i thought i did .........summat strange going on !!