i have a steep driveway i have to hit it speed to make it to the top rite at the top the motor has lost rpms to the point its pulling as hard as it can mabey 100 rpms a tinny rattling sound comes frome the top of the motor
it also happens when i lug it around at real low rpms under 10 miles an hour like around in a parking lot im also looking at my exaust i just installded a cr machine header kit on my chamber there are 2 springs that hold the chamber to the jug mabey rattling there? it didnt do it before
its a gasbike gt 80 kit on shwinn blackwell cruser bike high c head reed valves ported jug ported piston tranfers matched to cases 1979 rm 60 x chamber i sanded about a gasket and 1/2 off head to raise compression running reg gas at about 40 to 1 oil mix gets to over 35ish mph pulls fairly hard from about 7 or 8 all the way to top end almost forgot 40 tooth cog trying to build some tork into it
speaking of wristpin bearings, i was wondering same thing,, i heard they were having trouble with earlier wristpin bearings falling apart,,, i have a 09/09/2015 gt5 38mm stroke engine,,,i have looked at wristpins and it seems like there are three types,,, here are pictures of two,, the one is what came in my engine,, the other style is sold by JNM motors,,, should i change to different style,,, the third type has smaller length needles and more solid cage material,,,, and what size drill bit do you use to drill out wrist pin for less vibration ???
well i do belive i fixed it it was the header vibrateing when the ingine hit hard while pulling a load the cr machine header has 2 springs that hold the header onto the exaust mount i think the springs are letting the exaust bounce on the mount i made a new brace for the x chamber noise is gone thanks for all the info i learn new things every day