A3 Tecno circuit advice

Hey guys I have a quick question about the Techno circuit pipe on an A3 engine.

I have a 1995 Tomos sprint A35 engine with a 14.12 dellorto running a stock air filter, no airbox, 59 jet with the tecno circuit pipe and I hit about 38 mph consistently with wicked acceleration.

However I just got a techno circuit pipe for my girlfriends 91 Tomos Bullet with an A3 engine. Before putting on the circuit pipe she was running a 14.12 dellorto with a 57 jet(seemed big to me but PO had it in) with air filter and airbox attached and was hitting 30 mph, consistently. After putting on the circuit pipe and removing the connection boot to the airbox but leaving the stock air filter on and upjetting to a 59 her bike struggles to hit 25 mph. Is this a jetting problem or something else?

Thanks for your help guys.

TLDR: After throwing on a tecno circuit top speed and acceleration dropped.

Re: A3 Tecno circuit advice

My a3 with a bi turbo and 62 jet hits 32

Low-mid is meh

Re: A3 Tecno circuit advice

duh, upjet.

you guys should be seeing 35 on a stock a3 with basic de-restriction, if you're not you should tune it up before slapping on performance parts.

Re: A3 Tecno circuit advice

Thanks for the response guys. Well I upjetted her bike to the same jet I upjetted my bike to when I put a tecno circuit on (a 59), ill order a 60 range for it soon.

And by basic derestriction what do you mean? Things like boring out the intake, portmatching the intake and exhaust? trimming the piston skirt a few mm?

EDIT: Also a week ago I removed the stock air restrictor and her bike wouldn't start until I down jetted it to a 53 and it was running fine, however a bit too loud for her. When we put the pipe on and we put the restrictor back on and she hit a gps'd 25mph when I removed the restrictor she hit a gps'd 25mph again both with the 59 jet. (edited)

Re: A3 Tecno circuit advice

It might also depend on the engine. The "SP" will probably be faster and respond better to a pipe than the "GM". The GM has a longer piston skirt which makes the ignition port timing less ideal, it also has a larger rear sprocket.

Re: A3 Tecno circuit advice

I did 40mph on an A3 with an upjet on the 12mm encarwi, 27t front sprocket, a coca cola 12pk cutout base gasket and a techno circuit.

Re: A3 Tecno circuit advice

Ok update, Upjeted to a 64 replaced intake,base, carb shim, and exhaust gasket. Shim now leaks more then before, but no other air leak, but its still only hitting 29. Going to clean the points and check timing soon.

Any idea why the speed is so low? Are the A35 engines that much more powerful then the A3?

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