Post by Airpressure on Apr 3, 2006 11:55:42 GMT -5
Tuning tuning tuning the most asked question in the RC hobby. So I have put together some basic pointers on how to get your nitro engine running perfectly.
For the HSN (high speed needle)
This is the most commonly adjusted needle on any nitro engine. The HSN is what mainly controls the high speed. It is critical to get the HSN as perfect as you can. So this is what helps to get it adjusted just right.
Always have a good trail of blue smoke coming from the stinger of the exhaust pipe when you hammer the throttle. During a high speed run you should see blue smoke coming from the exhaust through the entire powerband. If there isn’t any blue smoke coming from the stinger or very little than that means your too lean. It is important to not get the HSN to rich or it will flood out the engine when you hit the throttle. One good way to tune the HSN is start off real rich and then lean it every few minutes of run time until you get it to run just perfectly then back off a 6th of a turn, that will keep it in a good condition for running everyday and having good engine life. If you lean the high speed needle (clockwise) and it started overheating that means you need to richen it a 4th of a turn and try again, just try not to lean the needle that far in this time.
For the LSN (low speed needle) and idle
This is mainly going to affect the idle and acceleration. It is also important to get this needle set as good as you can.
If your idle decreases after running the nitro engine for a while than that is a sign of the LSN being to lean, fix it by richening the needle (spinning it counter clockwise). If you seem to have an unsteady idle (meaning the engine has an unsteady idle speed) that is a sign of the LSN being to rich. Remember when you lean the engine the idle will become faster than it was originally fix that by turning the idle screw counter clockwise. If you take a high speed run and then let it sit and idle for about 5 seconds and then when you hammer the throttle and it is kind of sluggish that is also a sign of the LSN being to rich
I know that tuning a nitro engine can some times get very annoying and just about impossible at sometimes. So here is some common problems that I hear and the cures for them.
1. I have heard people say they have the problem of there engine stalling after a high speed run. The most common reason this happens is the LSN (low speed needle) is too lean. If this problem continues and you have richened your LSN it could be time for an engine rebuild.
2. The question “sluggish acceleration” comes up just about all the time. The most common cause of this problem is a rich LSN. It may sound something like burrrrrrrrrr. The engine is actually “loading up” with lubrication and unburnt fuel because there is not enough available air to burn off all the excess fuel. Lean the LSN and it will most likely do better.
3. If you normally have great acceleration but after your engine sits at idle for about 10 seconds and then you hit the throttle and it has a sluggish take off it is another sign of the LSN being to rich.
5. If your idle is unstable or changes speed every few high speed runs you take, the LSN is most likely too lean.
6. If your idle only lasts a short period of time before slowing down and eventually stalling, your LSN is too rich. It gets too much lubrication which slows the engine speed down.
Well we are now done with just about all the LSN problems I can think of right now. Now on to the HSN
1. It won’t shift into 2nd gear all the time. That is either a to rich HSN or your shift point is set for a to high RPM. If it is because your engine is running rich just lean it about 1/12 of a turn every few high speed runs and see if it starts to shift to 2nd gear.
2. Engine stalls when I hit the throttle wide open. This is just about always because your HSN is WAY to rich. Unless you have been driving it at super slow speed for a long time, it will most likely be a rich HSN.
3. Cuts out when I hit the throttle wide open. This is either a real lean HSN or a bad glow plug. If it is a lean HSN don’t ever keep driving it like that Very bad for you engine!
4.4. If you have been driving your nitro engine for about half a tank and then it starts to bogg down, (it may also sound like burrrrrrrrrrrrrrrrrrrrrr) That is a sign of “overheating” (the piston and sleeve expand more the the proper amount) the engine isn’t getting the proper amount of lubrication so it has a higher temp. than normal. It means you are too lean on most likely the HSN (high speed needle) or it could be both needles.
Remember this is just stuff I have found to help it may be different from what some of you have expeirienced.
Airpressure’s tips&tricks
For the HSN (high speed needle)
This is the most commonly adjusted needle on any nitro engine. The HSN is what mainly controls the high speed. It is critical to get the HSN as perfect as you can. So this is what helps to get it adjusted just right.
Always have a good trail of blue smoke coming from the stinger of the exhaust pipe when you hammer the throttle. During a high speed run you should see blue smoke coming from the exhaust through the entire powerband. If there isn’t any blue smoke coming from the stinger or very little than that means your too lean. It is important to not get the HSN to rich or it will flood out the engine when you hit the throttle. One good way to tune the HSN is start off real rich and then lean it every few minutes of run time until you get it to run just perfectly then back off a 6th of a turn, that will keep it in a good condition for running everyday and having good engine life. If you lean the high speed needle (clockwise) and it started overheating that means you need to richen it a 4th of a turn and try again, just try not to lean the needle that far in this time.
For the LSN (low speed needle) and idle
This is mainly going to affect the idle and acceleration. It is also important to get this needle set as good as you can.
If your idle decreases after running the nitro engine for a while than that is a sign of the LSN being to lean, fix it by richening the needle (spinning it counter clockwise). If you seem to have an unsteady idle (meaning the engine has an unsteady idle speed) that is a sign of the LSN being to rich. Remember when you lean the engine the idle will become faster than it was originally fix that by turning the idle screw counter clockwise. If you take a high speed run and then let it sit and idle for about 5 seconds and then when you hammer the throttle and it is kind of sluggish that is also a sign of the LSN being to rich
I know that tuning a nitro engine can some times get very annoying and just about impossible at sometimes. So here is some common problems that I hear and the cures for them.
1. I have heard people say they have the problem of there engine stalling after a high speed run. The most common reason this happens is the LSN (low speed needle) is too lean. If this problem continues and you have richened your LSN it could be time for an engine rebuild.
2. The question “sluggish acceleration” comes up just about all the time. The most common cause of this problem is a rich LSN. It may sound something like burrrrrrrrrr. The engine is actually “loading up” with lubrication and unburnt fuel because there is not enough available air to burn off all the excess fuel. Lean the LSN and it will most likely do better.
3. If you normally have great acceleration but after your engine sits at idle for about 10 seconds and then you hit the throttle and it has a sluggish take off it is another sign of the LSN being to rich.
5. If your idle is unstable or changes speed every few high speed runs you take, the LSN is most likely too lean.
6. If your idle only lasts a short period of time before slowing down and eventually stalling, your LSN is too rich. It gets too much lubrication which slows the engine speed down.
Well we are now done with just about all the LSN problems I can think of right now. Now on to the HSN
1. It won’t shift into 2nd gear all the time. That is either a to rich HSN or your shift point is set for a to high RPM. If it is because your engine is running rich just lean it about 1/12 of a turn every few high speed runs and see if it starts to shift to 2nd gear.
2. Engine stalls when I hit the throttle wide open. This is just about always because your HSN is WAY to rich. Unless you have been driving it at super slow speed for a long time, it will most likely be a rich HSN.
3. Cuts out when I hit the throttle wide open. This is either a real lean HSN or a bad glow plug. If it is a lean HSN don’t ever keep driving it like that Very bad for you engine!
4.4. If you have been driving your nitro engine for about half a tank and then it starts to bogg down, (it may also sound like burrrrrrrrrrrrrrrrrrrrrr) That is a sign of “overheating” (the piston and sleeve expand more the the proper amount) the engine isn’t getting the proper amount of lubrication so it has a higher temp. than normal. It means you are too lean on most likely the HSN (high speed needle) or it could be both needles.
Remember this is just stuff I have found to help it may be different from what some of you have expeirienced.
Airpressure’s tips&tricks