What rpm is the mach 15 that comes in the xxxnt sport supose to spin up to? mine seems to be spinning real slow.... like it only takes about 10 feet and it wont climb anymore...im gonna say its at around 18k rpm... all the other engines i hear seem to spin alot faster, i thought it might be too lean or something but it stays around 250 degrees so iunno....

sounds too rich, what does it bog down? maybe your clutch?

the mach 15 hits about 30k rpm. does it start easy? Without your glowplug starter in try to pull the cord, if pulls super easy you have a problem with compression. oh and check your transmitter for a throttle travel adjustment set it zero if it isnt already there.

Yeah, your either too rich or too lean, try this, open up both needles 1 1/2 turn and change the plug. Slowly dial in your high speed until the peak is reached, then you can work on the low needle. You want it to run at about 220-240 degrees, any hotter and you might be in danger of destroying it. The motor should idle high for a few seconds (10) after running up to peak and settle down into it's low idle after the pause. Don't worry if it slightly hesitates after sitting, it's just loading-up and neds to be cleared. But by all means, don't lean it to the point of sagging on a high speed pass. My mach .15 will keep up with my friends team orion wasp 15, it doesn't spool up as fast but it will keep pace with him from lap to lap.