problem with .21 nitro engine
03-19-2013, 10:09 AM
#1
problem with .21 nitro engine
Im having a problem with a nitro engine that is making me want to pull my hair out! I custom build a USMTS style dirt modified chassis and used a parted out an exceed madfire for the engine, transmission, etc. Before I parted the exceed out and it was still in the buggy, I had a problem with the engine only 1 time. I was bashing and hit WOT and all the sudden the engine just shut off. I tried refireing it but it wouldn't refire. The next day I started it up and it ran just fine like nothing had ever even happened. I then parted it out and installed it in my custom car. It sat and didn't run for about 3 months. Now that its in my dirt modified, its acting very very strange. Its giving symptoms of being way to lean, but is pouring gas out of the exhaust and leaving nitro trails like it is WAY WAY to rich. I tried tuning on it, putting a new glow plug in it, same results. If I hit WOT, it will hiccup like its way to lean, and sometimes just shut off. The only thing that I can think is maybe it is maybe an air leak somewhere? Also the fuel line and repressure line's are much longer on my custom car than it was on the exceed. Would that have an effect on anything? Any help would be great!
03-19-2013, 07:19 PM
#3
start the engine and then take a can of wd40 and spray a little around the backplate and where the carb mounts to the block to check for an air leak, if its sucking air it will kill it, this is how i found my air leak, or just reseal the engine. even better yet send her in to rex (the guy who posted before me) and have him rebuild it, then you will have an engine that runs like new, well better actually in my case.
03-22-2013, 03:53 PM
#4
thanks for the responses guys. Tried spraying wd40 around the backplate and carb and the engine didn't even sputter. I measured the pressure and fuel line. The pressure line is 14 inches and the fuel line is 13 inches with a fuel filter spliced in the middle. Long I know, but since the tank is mounted in the back of the car behind the rear axle, and the engine is mounted in the front, there's no way around it. Tried tuning on it again because I read somewhere that when you lengthen the fuel line, you tend to have to run it much more lean but it still died at about half throttle :/. Also the nitro line that i had was .02mm smaller in diameter. Wonder if its running out of fuel in the fuel line when I give it gas?
Last edited by gdog427; 03-22-2013 at 04:40 PM.
03-22-2013, 05:14 PM
#7
yeah, i thought the same thing. Going to replace the o ring on the gas tank and see if that has any effect. Pick up is towards the front of the car. Wish i could post a picture of it but i don't have enough posts
03-22-2013, 07:54 PM
#9
If you have poor power a rich setting can shut down your engine... There's a difference between a lean bog and a rich bog.. If your spilling out fuel and its lean then you need to take a look at the fuel system and engine.. f you had a issue with your tank you would loose pressure not increase pressure.. Also have you checked your glow plug if so what did it look like..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
03-22-2013, 08:40 PM
#10
If you have poor power a rich setting can shut down your engine... There's a difference between a lean bog and a rich bog.. If your spilling out fuel and its lean then you need to take a look at the fuel system and engine.. f you had a issue with your tank you would loose pressure not increase pressure.. Also have you checked your glow plug if so what did it look like..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
03-22-2013, 11:13 PM
#11
If you have poor power a rich setting can shut down your engine... There's a difference between a lean bog and a rich bog.. If your spilling out fuel and its lean then you need to take a look at the fuel system and engine.. f you had a issue with your tank you would loose pressure not increase pressure.. Also have you checked your glow plug if so what did it look like..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
Sounds like your not that experienced no offense seek help from a local hobby store or a racer within your area..
. I took a look at the system and made sure that the tank was holding pressure. Same with all of the fuel lines and all is good. I think im going to take the engine apart and re seal everything just to check that off of the list of possibility's.
03-23-2013, 09:19 AM
#12
before you pull the back plate out rotate the crank up on a up stroke.. Then take off the back plate, you don't want to damage your sleeve...
A good way to check your tank is to take it out and submerged in water.. Blow into the exhaust hose and plug the fuel outlet hose.. If you see bubbles then you have a seal issue or a cracked tank.
Change your glow plug.....
A good way to check your tank is to take it out and submerged in water.. Blow into the exhaust hose and plug the fuel outlet hose.. If you see bubbles then you have a seal issue or a cracked tank.
Change your glow plug.....
03-23-2013, 09:21 AM
#13
03-23-2013, 10:52 AM
#14
no offense taken bud. That's because i'm not very experienced with these. I race real USMTS dirt modified's. RC is something I fiddle with when i have time or when i feel like it that's why i'm asking for help on this forum . I took a look at the system and made sure that the tank was holding pressure. Same with all of the fuel lines and all is good. I think im going to take the engine apart and re seal everything just to check that off of the list of possibility's.
. I took a look at the system and made sure that the tank was holding pressure. Same with all of the fuel lines and all is good. I think im going to take the engine apart and re seal everything just to check that off of the list of possibility's.Rex
03-23-2013, 03:11 PM
#15
Im having a problem with a nitro engine that is making me want to pull my hair out! I custom build a USMTS style dirt modified chassis and used a parted out an exceed madfire for the engine, transmission, etc. Before I parted the exceed out and it was still in the buggy, I had a problem with the engine only 1 time. I was bashing and hit WOT and all the sudden the engine just shut off. I tried refireing it but it wouldn't refire. The next day I started it up and it ran just fine like nothing had ever even happened. I then parted it out and installed it in my custom car. It sat and didn't run for about 3 months. Now that its in my dirt modified, its acting very very strange. Its giving symptoms of being way to lean, but is pouring gas out of the exhaust and leaving nitro trails like it is WAY WAY to rich. I tried tuning on it, putting a new glow plug in it, same results. If I hit WOT, it will hiccup like its way to lean, and sometimes just shut off. The only thing that I can think is maybe it is maybe an air leak somewhere? Also the fuel line and repressure line's are much longer on my custom car than it was on the exceed. Would that have an effect on anything? Any help would be great!
You could also have a hairline crack in the case. I see this a lot if you like send it in and I can check it out and figure out whats going on with it if your stumped anf have checked everyting on the chassis.