4 Stroking at WOT after break in

So I just got my 60cc head kit broke in with a delorto sha 15.15 jet size 72 I believe. And at top end it 4 strokes almost every time. Once it is heated up does it less but still 4 Stroking WOT maxed out flats with high head wind(20mph) I'm getting 31mph. I am also running the pro circuit exhaust. Thanks in advance


Re: 4 Stroking at WOT after break in

Probably Fred /

It could be the timing is too low, if it is your head temperature will be very low,

So set the timing to correct specifications with the timing light and then see If the head temperature gauge gets into low 300’s°F

If all that checks out see if your compression is correct, you might have cylinder, ring or piston damage,

72 jet works for a lot of things but it depends on what filter you have, if you have a high restrictive filter the 72 jet could be too high but timing setting always comes before jetting

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