pm tuning exhaust makes bike slower

hi
ive got a piaggio diesis 100 (85cc 2stroke), the standard exhaust is crap and i wanted to replace with a a performance pipe but none are made for this engine had a look in the garage and found my pm tuning pipe off the nrg 70 i had. i managed to fit it with a bit of mods to the brackets. its now down on power. ive tried upjetted the carb and its worse than standard jet size. could the pipe be to restrictive for a 85?

 

Yes!

 

Yeah the diameter of the expansion chamber is too small for the cc of the engine, so it's making it lose power

 

Thanks it was wishful thinking I know. Just missing the tinging noise from my old bike lol

 

You wanna sell that pipe my mate just snapped his 360 pipe he might be after another

 

Yeah I don't need it anymore lol its done about 2 miles before I sold the bike. I'll send you some pics through pm when I get home

 

Yo...i dont understand i have a 02 piaggio diesis 100cc had a stock exhaust was blowing and all around "knackerd" so my mate had a leo vince handmade tt off his old nrg had a slight bend down near the manifold end i put it on my diesis and its put at least 20mph on the top end before it was doing 50 and the speedo wouldnt go further now it goes off the clock 75 80 !!! these bikes are fast and everything as far as i know is stock except from that handmade tt

 

Do you know where I could get an exhaust system for my piaggio diesis 100cc 2t year 2002 or what other ones would fit...

 

could it be the pipe has pushed the power further up the rev range and you now need lighter rollers ?