Advanced carb tuning question - wot and half throttle same power

Ben Dover Swe

Well-Known Member
Recently installed 25mm carb on my 172cc aprilia. Using stock air box with malossi red filter. Stock 125cc exhaust (not sure if catalyzed or not).

Problem:
When opening throttle half, I get good power. But when open throttle fully, it is same power as on half. I would expect it to give more power on wot than on half. Why don't get more power on wot?

Important details:
Throttle cable opens carb fully. Carb is pretty good setup I think.
Made it fourstroke at wot and then lowered main jet until not four stroking.
Made it fourstroke at half throttle then moved position up until not four stroking.
Pilot 45. Stock needle at topmost position. 92 main jet.

What can it be? The only thing I can think of, is that stock air box is limited and is starving the carb on wot, and 92 main jet suits this air starved situation well. Ie. opening filter more and increasing main jet would give more power. Would this make sense or wtf is going on?
 
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