I'm currently porting a TY 175 for a customer who competes in vintage trials. But the problem for him is that it performed like a moped without pedals. So I have done much work to help with that problem including installing a case port that will dramatically improve the snap he desires , along with exaust port , boost port and transfer port mods. It looks racy but the timing is mild. Also will be installing a 28mm VM carb with 6 venture dividers and a ufo.

Rich

More pics that didn't fit

Rich

Big oops! I titled it a YT not a TY Forgive me

Rich

yeah YT--3 wheeler-- had me worried as they're dangerous enough in std trim. TY--i have a TY cylinder on my old AT1 piston port 125. Think i have a base plate under it due to conrod length & couldn't be bothered changing it. In fact the bottom end has never been apart since new. Anyway--TY top end goes very much better on this than as a trials bike possibly due to the trail exhaust & 28 carb & has 'willing' top end & over-rev. AT1 pipe i gutted about 35 years ago when it got choked up. Very interesting looking at porting changes from people that know what the're doing!! & thanks for posting. Hope he has a clean exhaust even if it's a std TY pipe--exhaust & tail pipe muffler especially the spark arrestor bit down the end.

Exemplary work Rich.

thank you very much

Rich

How did this turn out?

Were the porting modifications suited to trials riding?

Turned out gerat !  Very suited for trials . He competes in vintage trials. I can port for any application.

Rich

The transfer ducts are very restrictive on TYs. Case port is one way to improve things, but scalloping the liner, adjacent to the A transfer entries, is easier to do. If you can find a DT175 443 cylinder, with slight modification a V Force YZ85 reed block will fit, and in conjunction with a 26mm carb and bigger air box, will mean a 175 which runs as well as a Fantic.

Hey Rich,
Just curious. Did your TY porting customer also have you do venturi dividers on his Hodaka? And is he from Georgia?