I got one off of another member, but had trouble starting it. When I removed the glow plug to check it. It would light up, but it made a sizzling sound and some smoke came out, so I switched plugs. Car started right up. I ran it with 15% and accelaration was weak and top speed was probably around 15-17mph. I stopped it and saw some smoke come out of the exhaust. When I tried to restart it, it wouldn't. Took it home, checked the plug and the new one did the exact same thing as the old one had done. So I switched it back to the old plug, which was not sizzling anymore, and now it started again.
What is the problem with the car and how can I fix the accelaration/top speed issue.

thanks.

check your needles...

also check the idle set screw... when the throttle is closed, there should only be a gap opening of about 1 to 2 mm.

Also make sure that the flywheel is tight on the crank shaft. You check this by holding the flywheel and the then start to pull the pullstart. You should not be able to stop the flywheel from turning. If you can, then that is your problem.

Jude,
You should be running 30% nitro, the smoke and sounds you hear on your plug are from left over fuel/oil, that is normal, infact if it doesn't light up, smoke or sizzle the plug is no good.

It sounds to me like your engine just needs to be tuned a bit, I would go out and get some good 30% fuel (Sidewinder, Byrons) and start to re-tune your engine. chances are that your carb was set way too rich for 15% nitro..

You shouldn't be running anything less than 30% in the mini nitro motors.

I just picked up some Traxxas 33% fuel for my 2.5R Motor. Can I use that in the IRC?

ya traxxas 33 percent will work.

ive actually beenusing 20 percent nitro in mine and it ran pretty well, but i dont know. im only a 14 year old!