More polini problems

Last week i was riding my maxi for the second time and the head gasket blew out and caused me to soft seize. after fixing that every time i go out for i ride i get to nearly the same spot down the road (4 miles) and it loses all power, slows down to 5mph, not suddenly like a seize its more like its ran out of gas.

Also the burn pattern on the head is focused on the exhaust side,

is that normal? i thought you wanted an even burn pattern?

Re: More polini problems

oh and my setup is:


dmp stuffed

techno boss

64cc polini

15mm bing

high flow filter

the needle is set at second from the bottom, also what range does the need affect?

also it does the same thing with an 84 and 94 jet but it four strokes with the 94.

Re: More polini problems

also i should note that this is happening while im riding 3/4 throttle and going about 45.

Re: More polini problems


Re: More polini problems

get your needle at the 2nd position from the top, and try starting at a 92 main jet.

keep the needle at 2nd until you find the right (rich for break in) jet

what cylinder head are you using?

oh! and no sythetic oil for breaking in, run like 4 oz of oil to every gallon with the cheap stuff until the rings wear in.


Re: More polini problems

I had the same problem last week--exactly as you described it.

Turned out my 70cc HC head was warped ever so slightly by the bottom left bolt hole and would never fully seal.

Re: More polini problems

honestly guys. i dont use head gaskets, ever.

the best head you can get is a stock puch high comp with the seal ring that came on the high torque closed port cylinders.


Re: More polini problems

its the 50cc high comp head from treats.

and i know for sure there was no head leak..

i wasnt running a gasket just copper rtv and i had to us a screw driver between the fins to break the head loose from the cylinder (it was off of the bike) and no signs of leaking at the head but the base gasket had an airleak.

also what spark plug are other people running with similar setups? thanks for all your help!

Re: More polini problems

Since i have the cylinder off now i went ahead and cut out the bridge in the reed block and bent the tabs back to allow the reed to open more.

Re: More polini problems

suggestions for spark plug?

Re: More polini problems

b8hs or b9hs,you dont need a hot plug on a kit turning higher than stock rpms

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