Diver6127
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I came across this article in R/C nitro. Thought it could help a lot of us :n00bie:'s
End the Frustration by Kevin Hetmanski
Engine inspection
Give the engine a good once-over:
• Screws. Make sure that all the screws are tight and in place. Loose or missing screws are a very common cause of engine problems yet are often overlooked.
• Flywheel. Spin the flywheel to see whether it’s firmly attached to the crankshaft. A loose flywheel, though difficult to detect, can make an engine nearly impossible to start.
• Idle-speed screws and mixture needles. I know this sounds crazy, but be sure to check whether your idle-speed screw and mixture needles on the carburetor are still there. Typically, the mixture screws loosen over time, and in extreme cases, they can even vibrate completely out of the engine.
Engine wear
More than half of the engines I’ve been asked to help start are so badly worn that I’m amazed they started in their owners’ previous 100 attempts. Engine wear makes starting increasingly difficult, and eventually, the engine won’t start at all. The critical components here are the piston and sleeve; more specifically, the fit between the two. An excessively worn piston and sleeve won’t create enough pressure in the crankcase to force fuel through the transfer ports and into the cylinder. After combustion, much of the cylinder pressure above the piston bleeds past the piston, too. More simply, the engine won’t run well, if at all, if the piston and sleeve are excessively worn. Check for wear by rotating the flywheel counterclockwise. With the glow plug in place, if you can easily rotate the flywheel with one finger, it’s time to start shopping replacement parts or a new engine.
Defective glow igniter or plug
Above: The gauge on top of this glow igniter tells you whether the glow plug is defective or whether the glow igniter’s battery is dead.
You should check both the glow igniter and glow plug for possible problems. Here’s how:
• Glow igniter. Before you start, make sure that the glow igniter is fully charged and working properly. Partially install a spare glow plug to check the glow igniter’s condition and the state of its charge. If you fully install the glow plug in the igniter, you might find it difficult to remove, especially when it starts to get very hot. Simply hold the glow plug by its housing (keep your fingers away from the element), and lightly press it into the igniter’s contacts. The plug should glow bright white/orange. Also check whether the end of the glow igniter is clean and allows a good contact between it and the glow plug.
• Glow plug. If the glow igniter checks out, move on to the glow plug you’ve installed in the engine. Clean out the area around the glow plug (very important) and remove the plug from the engine. Insert the plug into the glow igniter (which you already know works properly), and make sure that the plug’s coil lights up properly. If it doesn’t, you need a new plug. If the glow plug does light but is a deeper orange color than it should be, it might be fouled or have some other flaw that will prevent it from working properly. A tip-off is that the engine dies as soon as you remove the glow igniter from the glow plug; don’t confuse this with problems caused by having an excessively rich fuel mixture.
Some glow igniters are designed to make it easier to diagnose a plug problem. They have a built-in gauge that can help you with the two most common plug problems: the glow igniter is not charged, or the glow plug has failed completely. If you know you have a full charge on the glow igniter and the gauge is still in the red, you know the plug is the problem.
If you use an on-board electric starter, you might have problems heating the glow plug completely. When the engine is new or flooded, the starter motor works harder than normal to get the engine cranking. This heavy power drain results in a measurable drop in the power remaining to ignite the glow plug. This power drain reduces the glow plug’s effectiveness and makes it harder to start the engine. Use a separate glow igniter as an independent power source to help get the engine started.
Stale fuel
Take care of your fuel; don’t let it sit around too long. Condensation and evaporation are leading causes of problems with old fuel. If you leave the cap off the fuel bottle for too long, moisture will literally be sucked in, and the methanol will quickly evaporate. Engines don’t run too well on a water/nitro blend! If you aren’t sure how long your fuel has been sitting around, it has probably been too long. Buy new fuel
Fuel-system problems
The fuel system is important when it comes to getting your engine fired quickly. A typical fuel system includes: a tank, a fuel line that connects the tank to the carburetor, a pressure line that feeds exhaust pressure into the tank for consistent fuel delivery and, possibly, a fuel filter.
• Fuel tank. The fuel tank should be clean and free of any obvious defects. The most common fuel tank problems are a faulty seal between the filler cap and the tank, a worn O-ring seal on the primer pump (if it’s so equipped), plugged or restricted fuel flow through the pick-up, or a crack in the tank. Any of these problems can mean an air or fuel leak that will compromise the engine’s ability to start and run properly.
The key is that the fuel system not only be free of fuel leaks but also be airtight. Air leaks in the fuel system cause uneven pressure in the fuel tank and excessive air bubbles in the fuel lines. Both of these can make starting and tuning the engine more difficult. It isn’t unusual to have a few air bubbles in the fuel line, but yo
u might have problems if you have excessive, persistent bubbles.
Fuel lines and pressure lines. These are often overlooked during troubleshooting because damage isn’t always obvious. The most common problems are small cuts in the lines (sharp or abrasive edges or rotating drive components are often the culprits here). Though hardly visible, these cuts in the lines can adversely affect engine starting and tuning, just as a faulty fuel tank can.
• Fuel filter. Finally, do you have a fuel filter? A filter can protect your engine by preventing debris from getting inside it from the fuel tank. But if it’s poorly maintained or badly designed, a fuel filter can cause as many problems as it solves. Debris can gradually clog a fuel filter to a point that the fuel won’t flow sufficiently even to start the engine. A clean but poorly designed filter can also restrict fuel flow and cause many of the same problems as a dirty, well-designed one. Check your fuel system for sufficient flow with the filter installed to ensure that it’s not the cause of your starting problems.
To test the entire fuel system, remove the fuel line from the carburetor and insert it into your fuel bottle. Next, remove the pressure line from the muffler or tuned pipe and gently blow into it. Fuel (or air, if the tank is empty) should flow freely from the fuel line to the fuel bottle. If it doesn’t, follow a process of elimination:
• Carburetor. OK; the fuel flows freely through the fuel system, but your engine still won’t start. Look at the carburetor, and eliminate the obvious problems: a loose carburetor clamp holding the carb to the engine, screws missing, etc. If everything checks out, move on to the next few steps.
• Idle speed. This is the most common cause of engine problems. You might use the radio trim feature to set the engine’s idle speed, and then you can’t figure out why the engine dies when you apply the brakes. Adjust the idle-speed screw to prevent the carburetor from closing more than 1mm under any circumstances.
Check whether your engine has enough compression by turning the flywheel with one finger. There should be some resistance when the piston reaches top dead center.
• Mixture-needle settings. These are the second most frequent cause of engine headaches. If the mixture needles are too far out of adjustment, the engine will either flood quickly or will never get enough fuel to start in the first place. Either way, you need to adjust the mixture needles correctly for the engine to start. Engines vary, but generally, you follow the same steps: first, close the needles by gently turning them clockwise until you feel a slight amount of resistance; this is the closed position. Then turn the needles counterclockwise. Open the main needle 2 1/2 to 3 turns and the low-speed mixture about 1 to 1 1/2 turns. Once the engine starts, you can fine-tune the mixture settings for performance.
Starter Problems
You need to use either a starter box or a hand-held starter to get your engine started properly. RC engines have been known to start and run in the wrong direction. If your starter runs in the wrong direction, reverse the positive and negative leads that connect its motor to the battery, or if you use a hand-held starter, rotate the starter 180 degrees.
Don’t think that you’re immune from starting your engine backwards if you have a pull-starter, either. You may have installed the one-way bearing in the pull-starter or electric starter backwards during assembly or maintenance, and that will make the engine crank backwards! Before you eliminate this as a possibility, give the pull-start a quick pull to see whether it is cranking the engine in the right direction.
Faulty clutch
If you look closely at the end of this clutch bell, you can see that the bearing has blown up and only has one ball left in the inner race. This caused the engine to shut down several times. As the bearing self-destructed, the crankshaft wasn’t able to spin.
A defective clutch can cause starting problems. The engine will start and run when you hold the car up, but it stalls when you apply the brakes or when you put it on the ground. Fortunately, you can quickly diagnose a faulty clutch. The most obvious sign of a clutch problem is that the vehicle’s wheels spin continuously, even when you’ve set the engine to low idle speed. A properly functioning clutch should disengage at low idle speeds and should allow the engine to run without its wheels turning. Some damage to the clutch shoe or springs is usually the culprit. A dirty or seized bearing(s) on the clutch bell can also create the same problem.
These tips describe some of the barriers to starting your engine. This might seem to be a long checklist, but when your engine is giving you trouble, these checks actually take very little time to do. The problem areas will become even easier to recognize as you gain experience, so keep at it, and it won’t be long before you’ll be able to solve your engine troubles like a pro!
End the Frustration by Kevin Hetmanski
Engine inspection
Give the engine a good once-over:
• Screws. Make sure that all the screws are tight and in place. Loose or missing screws are a very common cause of engine problems yet are often overlooked.
• Flywheel. Spin the flywheel to see whether it’s firmly attached to the crankshaft. A loose flywheel, though difficult to detect, can make an engine nearly impossible to start.
• Idle-speed screws and mixture needles. I know this sounds crazy, but be sure to check whether your idle-speed screw and mixture needles on the carburetor are still there. Typically, the mixture screws loosen over time, and in extreme cases, they can even vibrate completely out of the engine.
Engine wear
More than half of the engines I’ve been asked to help start are so badly worn that I’m amazed they started in their owners’ previous 100 attempts. Engine wear makes starting increasingly difficult, and eventually, the engine won’t start at all. The critical components here are the piston and sleeve; more specifically, the fit between the two. An excessively worn piston and sleeve won’t create enough pressure in the crankcase to force fuel through the transfer ports and into the cylinder. After combustion, much of the cylinder pressure above the piston bleeds past the piston, too. More simply, the engine won’t run well, if at all, if the piston and sleeve are excessively worn. Check for wear by rotating the flywheel counterclockwise. With the glow plug in place, if you can easily rotate the flywheel with one finger, it’s time to start shopping replacement parts or a new engine.
Defective glow igniter or plug
Above: The gauge on top of this glow igniter tells you whether the glow plug is defective or whether the glow igniter’s battery is dead.
You should check both the glow igniter and glow plug for possible problems. Here’s how:
• Glow igniter. Before you start, make sure that the glow igniter is fully charged and working properly. Partially install a spare glow plug to check the glow igniter’s condition and the state of its charge. If you fully install the glow plug in the igniter, you might find it difficult to remove, especially when it starts to get very hot. Simply hold the glow plug by its housing (keep your fingers away from the element), and lightly press it into the igniter’s contacts. The plug should glow bright white/orange. Also check whether the end of the glow igniter is clean and allows a good contact between it and the glow plug.
• Glow plug. If the glow igniter checks out, move on to the glow plug you’ve installed in the engine. Clean out the area around the glow plug (very important) and remove the plug from the engine. Insert the plug into the glow igniter (which you already know works properly), and make sure that the plug’s coil lights up properly. If it doesn’t, you need a new plug. If the glow plug does light but is a deeper orange color than it should be, it might be fouled or have some other flaw that will prevent it from working properly. A tip-off is that the engine dies as soon as you remove the glow igniter from the glow plug; don’t confuse this with problems caused by having an excessively rich fuel mixture.
Some glow igniters are designed to make it easier to diagnose a plug problem. They have a built-in gauge that can help you with the two most common plug problems: the glow igniter is not charged, or the glow plug has failed completely. If you know you have a full charge on the glow igniter and the gauge is still in the red, you know the plug is the problem.
If you use an on-board electric starter, you might have problems heating the glow plug completely. When the engine is new or flooded, the starter motor works harder than normal to get the engine cranking. This heavy power drain results in a measurable drop in the power remaining to ignite the glow plug. This power drain reduces the glow plug’s effectiveness and makes it harder to start the engine. Use a separate glow igniter as an independent power source to help get the engine started.
Stale fuel
Take care of your fuel; don’t let it sit around too long. Condensation and evaporation are leading causes of problems with old fuel. If you leave the cap off the fuel bottle for too long, moisture will literally be sucked in, and the methanol will quickly evaporate. Engines don’t run too well on a water/nitro blend! If you aren’t sure how long your fuel has been sitting around, it has probably been too long. Buy new fuel
Fuel-system problems
The fuel system is important when it comes to getting your engine fired quickly. A typical fuel system includes: a tank, a fuel line that connects the tank to the carburetor, a pressure line that feeds exhaust pressure into the tank for consistent fuel delivery and, possibly, a fuel filter.
• Fuel tank. The fuel tank should be clean and free of any obvious defects. The most common fuel tank problems are a faulty seal between the filler cap and the tank, a worn O-ring seal on the primer pump (if it’s so equipped), plugged or restricted fuel flow through the pick-up, or a crack in the tank. Any of these problems can mean an air or fuel leak that will compromise the engine’s ability to start and run properly.
The key is that the fuel system not only be free of fuel leaks but also be airtight. Air leaks in the fuel system cause uneven pressure in the fuel tank and excessive air bubbles in the fuel lines. Both of these can make starting and tuning the engine more difficult. It isn’t unusual to have a few air bubbles in the fuel line, but yo
u might have problems if you have excessive, persistent bubbles.
Fuel lines and pressure lines. These are often overlooked during troubleshooting because damage isn’t always obvious. The most common problems are small cuts in the lines (sharp or abrasive edges or rotating drive components are often the culprits here). Though hardly visible, these cuts in the lines can adversely affect engine starting and tuning, just as a faulty fuel tank can.
• Fuel filter. Finally, do you have a fuel filter? A filter can protect your engine by preventing debris from getting inside it from the fuel tank. But if it’s poorly maintained or badly designed, a fuel filter can cause as many problems as it solves. Debris can gradually clog a fuel filter to a point that the fuel won’t flow sufficiently even to start the engine. A clean but poorly designed filter can also restrict fuel flow and cause many of the same problems as a dirty, well-designed one. Check your fuel system for sufficient flow with the filter installed to ensure that it’s not the cause of your starting problems.
To test the entire fuel system, remove the fuel line from the carburetor and insert it into your fuel bottle. Next, remove the pressure line from the muffler or tuned pipe and gently blow into it. Fuel (or air, if the tank is empty) should flow freely from the fuel line to the fuel bottle. If it doesn’t, follow a process of elimination:
• Carburetor. OK; the fuel flows freely through the fuel system, but your engine still won’t start. Look at the carburetor, and eliminate the obvious problems: a loose carburetor clamp holding the carb to the engine, screws missing, etc. If everything checks out, move on to the next few steps.
• Idle speed. This is the most common cause of engine problems. You might use the radio trim feature to set the engine’s idle speed, and then you can’t figure out why the engine dies when you apply the brakes. Adjust the idle-speed screw to prevent the carburetor from closing more than 1mm under any circumstances.
Check whether your engine has enough compression by turning the flywheel with one finger. There should be some resistance when the piston reaches top dead center.
• Mixture-needle settings. These are the second most frequent cause of engine headaches. If the mixture needles are too far out of adjustment, the engine will either flood quickly or will never get enough fuel to start in the first place. Either way, you need to adjust the mixture needles correctly for the engine to start. Engines vary, but generally, you follow the same steps: first, close the needles by gently turning them clockwise until you feel a slight amount of resistance; this is the closed position. Then turn the needles counterclockwise. Open the main needle 2 1/2 to 3 turns and the low-speed mixture about 1 to 1 1/2 turns. Once the engine starts, you can fine-tune the mixture settings for performance.
Starter Problems
You need to use either a starter box or a hand-held starter to get your engine started properly. RC engines have been known to start and run in the wrong direction. If your starter runs in the wrong direction, reverse the positive and negative leads that connect its motor to the battery, or if you use a hand-held starter, rotate the starter 180 degrees.
Don’t think that you’re immune from starting your engine backwards if you have a pull-starter, either. You may have installed the one-way bearing in the pull-starter or electric starter backwards during assembly or maintenance, and that will make the engine crank backwards! Before you eliminate this as a possibility, give the pull-start a quick pull to see whether it is cranking the engine in the right direction.
Faulty clutch
If you look closely at the end of this clutch bell, you can see that the bearing has blown up and only has one ball left in the inner race. This caused the engine to shut down several times. As the bearing self-destructed, the crankshaft wasn’t able to spin.
A defective clutch can cause starting problems. The engine will start and run when you hold the car up, but it stalls when you apply the brakes or when you put it on the ground. Fortunately, you can quickly diagnose a faulty clutch. The most obvious sign of a clutch problem is that the vehicle’s wheels spin continuously, even when you’ve set the engine to low idle speed. A properly functioning clutch should disengage at low idle speeds and should allow the engine to run without its wheels turning. Some damage to the clutch shoe or springs is usually the culprit. A dirty or seized bearing(s) on the clutch bell can also create the same problem.
These tips describe some of the barriers to starting your engine. This might seem to be a long checklist, but when your engine is giving you trouble, these checks actually take very little time to do. The problem areas will become even easier to recognize as you gain experience, so keep at it, and it won’t be long before you’ll be able to solve your engine troubles like a pro!
