Reed stuffer - yes or no? (172cc ac, aprilia sr125)

[bendover]

I find contradicting information, some say to use it, some say not to use it? I want low/mid-end.

Currently bike is rich and fourstroking totally on anything except idle and wot, where it fourstrokes somewhat. Workshop say that removing it will lean it a bit. I doubt it will help, and that I will have to re-tune the carb myself. Question still stands though - should I use stuffer or not?

[pinkscoot]

Did you do any adjustment to the needle? The needle affects the mid range.

[spaz12]

I would use it.

[ThaiGyro]

Stuffing or not...a bit depends on crank port configuration/timing. That said, I am all for it. I find that altering space just before or on some engines, just after the reed block can deliver a smoother power-band. I too am always wanting more bottom to mid range. I do, however, find it somewhat harder to achieve than full blown top end!

Port timing is uber tricky, but fun to play with. My tendencies are to find what is max for the pipe, then push the ignition from stock to an advance that enables the desired power. I cannot wait for micro-FI! Will work with carbs too!

[jackrides]

A long time ago, Kawasaki had a 350 single rotary valve 350 (F5) with a serious 4 stroking issue. Fix was to raise the exhaust port 3 - 3.5 mm. Bore and stroke were 80.5 by 69 mm (or thereabouts). Worked great!