Piston sticks at the top of the cylinder (new engine).
The piston's tolerance inside the piston chamber is so tight, there is no room for the piston to slide to the top. The solution is to heat up the piston chamber with a hair dryer or heat gun. This will expand the chamber, allowing the piston to glide smoothly, while maintaining good compression.
Nitro engine dies as soon as you pull it off the starter box
If your RC car is decently tuned, your problem is probably a loose clutch nut . The clutch nut is what connects the flywheel to the crankshaft. Pressing down your RC car on the starter box presses the clutch nut against the fly wheel, creating the spin that gets your nitro started. However, if your clutch nut is loose from wear and tear or impacts, it won't have the proper mesh it
needs to keep the car running once you have removed your vehicle from
the starter box. To see if you have a loose clutch nut, look for the fly wheel spinning on it's own. If it does, you need to remove the engine and tighten
or replace the clutch nut.
Does your Engine stall when the tires hit the ground?
A frozen clutch-bell bearing or broken clutch-retainer spring is the most likely culprit. The engine stalls because the clutch is engaged when the engine is idling. When you put the car on the ground the engine croaks as it is not
running fast enough to move the car. The retainer spring or clutch bell bearing are forcing the clutch to be engaged when it shouldn't be. You'll need to inspect both parts and repair or replace as required.
Did your Nitro Power Plant just start backwards?
This is a common problem, with an easy fix as it is always caused by user errors. Make sure you put your RC car on the starter box with the correct orientation and that you put your wires on the correct poles of the battery.
Your engine dies while warming up.
The most probable cause of this is a worn piston and/or cylinder sleeve. When the engine is cold, compression is adequate to get it started and run nicely. As it warms up the fit between piston and sleeve loosens up as the sleeve expands. If the fit is bad enough, your fuel can exit the cylinder above the piston . As the engine gets warmer, this effect gets worse until the engine eventually stalls. You'll need to replace the engine or, if you like working on this kind of thing, the piston and sleeve.
Your roto-start or pullstart nitro won't start.
Your one-way bearing may not be catching on the crank shaft. This can happen if it is extremely dirty and you can clean it , let it dry overnight, and re-install it.
Your engine speed increases while idling.
Highly probable that the low speed needle on the engine is set too lean . A good confirmatory test is to pinch the fuel line and time how long the engine runs. If much less than five seconds it's too lean, if much longer than 5 seconds, it's too rich.
7 Tips To Get Your Rc Car's Nitro Engine Running
2:27 AM
Tuning Tips