Looking for some tuning advice.
I have a Start V with 65 cc metrakit, TM24 (15 idle jet, 165 main jet, middle needle position, 5n13 needle) 6 gram weights, 16/33 gearing, removed starter clutch, stock contra and variator. Rk replica huge moped pipe w/ black baffle. Malossi reeds. Timing 1.8mm. No air leaks with leak down test.
The bike is 4 stroking - a lot at 1/2 to WOT and less frequently at WOT. The bike accelerates decently until 1/2 throttle then there is a lot of hesitation and losing of power and spitting gas.
I have tried leaning the main down to 115 and needle position but this makes the bike run worst and there is still a lot of 4 stroking in the mid range. The plug looks to be on the richer side but not bad. The head temps hang around high 200s. Leaning up the main jet did improve the spitting of gas.
I was looking on the tuning spreadsheet. There is another guy with a metrakit, start 5, with a tm28 with a 185 main jet.
I feel like I need to down jet but I do not have any reference and the lowest jet I have is 115. Or am I totally out of the ballpark and need a leaner needle?