Hi, i know this subject has been discussed but can anyone out there tell me if they have had thier RS200 Seeley motor bored out and what piston was fitted?, and if they had to alter jets etc to suit. I am desperate for this info as i have a trial next weekend come on dont be shy help me out you lot!!!

I'm assuming it just needs a rebore to next oversize and you're not talking about a 220 or 230cc conversion.

Contact Gordon Farley motorcycles, number in TMX, and speak to Tim (I think) He knows which piston you can use to fit the Seeley as the Seeley had a bigger piston than the standard RS200 to make it 198cc and no-one seems to know what they came from. He got me a replacement for mine (actually had it in stock) which came from a ditch pump motor or something like. No jet changes should be necessary for a rebore and oversize piston.

I actually tried David Silver first but they didn't really know anything about Seeleys so I'd go to Farleys

Hey there Honda Pants and Woody,

If it's the same ditch pump piston that I think it is, here's a little information on it. This is a big TL motor. It has the Honda part number for the piston in the article.

http://www.kaila.net/tl125/tl125bigbore.html

Not sure if it's the same motor, but I used a one over Wiseco for and early 1980's XR 200. The compression ratio was a bit higher, but a thicker base gasket cured that. Go to the Wiseco page and scroll down until you get to the XR 200 entry. The print is small and there is a ton of info, so it is easy to miss. The part # I used for a 4156m06600. Cost for piston, rings, pin, and clips was about 125 dollars. Good luck. Oh, my TLR runs fine with this piston!