Nitro engines aren’t a plug and play deal like brushless power and because of that, time needs to be spent tuning and trouble shooting them in order to enjoy your time with them. These engines are very simple machines and don’t require much to run. If it’s getting air, fuel and spark, the engine will fire. But things don’t always go smoothly and there will be times where you have to figure out what the engine is asking for in order for it to run correctly. These 10 tips are here to help you end the frustration and start up the enjoyment.
Engine won’t start
Check to make sure that your glow starter is fully charged. You can quickly check by taking a new glow plug and plugging it into the end of the starter. If it glows, then it’s charged and the problem is somewhere else. If it doesn’t glow, then need to charge it or replace the battery and you should be good to go. If the glow starter isn’t your problem then you might have a bad glow plug. Remove the glow plug from the engine and test it by plugging it into the glow starter. If all else fails, check to make sure you have fuel in the tank. Yes, that’s something that people over look.
Engine starts but stalls right away
OK, so you fire up your engine and it’s running fine then the second you pull the glow starter off the heat sink head, the engine dies. This could be a sign of a glow starter that isn’t fully charged or a glow plug that is one the edge of going bad. Start by putting your glow starter on charge or replacing the battery and try it again. If the problem still happens, replace your glow plug.
Engine runs on starter box but stops when vehicle hits the ground or when you tap the brake
This is happening because there is something hanging up on the clutch and not allowing it to disengage from the drivetrain. So the second you stop the drivetrain in any way, the engine will die. The same thing happens when you hit the flywheel to shut the engine down. Remove the engine from the chassis and spin the clutch bell to see if there’s any drag or if it’s locked all together. If there’s drag on the clutch bell, then you may have a clutch shoe or clutch spring hanging up. If the clutch bell is locked up all together, you have a bad clutch bell bearing. Replace both bearings even if only one clutch bearing is bad because chances are that the other one is on the same path.
Engine stalls when you hit the throttle
This is a sign that your high-speed needle is set to lean and the engine is starving for fuel. Simply richen the high speed needle a quarter turn and make fine adjustments from there to get it set properly.
Engine looses power when you hit full throttle
This is a sign that your high-speed needle is set too rich. A sign is that the vehicle isn’t as fast as it was when the engine had a proper tune and you’ll see lots of smoke coming out of the pipe. Lean the high speed needle until your engine is running properly and at the correct temperature.
Engine struggles to move vehicle
Two things can be going on here. Your low-speed needle is set to rich or two lean. If you get on the throttle and your engine wants to die the second you touch it, your low speed needle is set to lean. If your engine is slow to react and stalls, then your low-speed needle is too rich. To check the condition of the tune on the low-speed needle, I like to do the pinch test. Drive the vehicle around if possible to clear it out and bring it over to you and immediately pinch the fuel line. You want the engine to run for a second or two before stalling out. If the engine dies right away, the low-speed is set to lean. If it takes longer, then your low-speed is set too rich. If you can’t get the vehicle to run enough to clear the carburetor out, perform the pinch test to get a general idea of where you’re at.
Engine runs too hot
An overheating engine can be caused by lack of air flow or a carb that is set to lean. Take a look at the body on your vehicle and make sure that there are venting holes in the windshield and behind the cab. Richen up the high-speed needle on the carb. A dirty engine can reduce the cooling capabilities of the engine and cause it to overheat. A tooth brush and some nitro cleaner will do a great job at removing any grime.
Fuel not reaching engine
If you are trying to fire up your engine and you see that the fuel isn’t flowing to the carburetor, you have a clog in the fuel system. You can check the fuel tank by removing the pressure and fuel line from the pipe and engine. Once they are removed, you can blow into the pressure line and look to see if any fuel comes out the other. The fuel should flow with no effort. If it takes a lot of pressure to make the fuel come out or it doesn’t come out at all, the fuel tank is clogged and needs to be replaced.
Engine runs erratically at idle
It can be frustrating when you can get the engine to idle consistently and that’s because of an air leak in the engine or fuel tank. Check the tank for leaks by plugging the exhaust and fuel lines and submerging it in water. While under water, check for air bubbles. Another area where you can find an air leak is in the fuel lines. If you see bubbles flowing inside the fuel line or suspect that is where your air leak is coming from, replace the line. It’s not expensive and needs to be done from time to time anyway. You can also take the engine apart and seal the back plate, carb, and high-speed needle assembly with O2 safe sealant.
Engine won’t turn over
Two things can keep an engine from turning over, too much fuel in the combustion chamber or a seized piston and or crankshaft. If your engine was turning over the suddenly locks up, chances are that you have a hydra lock condition where there’s too much fuel in the combustion chamber. All you have to do to fix it is remove the glow plug and turn the engine over to blow out the excess fuel. If that’s not the problem, then you’ll be replacing parts or an entire engine if you have a seized condition.
What is the ideal engine temperature?
There are a lot of theories out there on what the best operating temperature for your engine. Some look for an engine temp of 230 some may recommend a higher temp. Before running any nitro engine, take a look at the owner’s manual to see if there’s a recommendation there. Ever engine is different and a temp that will work for one engine might not be ideal for another.