too much fuel?

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RobH

Gone - bye bye.
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My son's Nitro Hawk is having an odd fuel problem.

The thing ran rich from day 1 (bought it used). I didn't want to mess with it cause the thing worked. When it didn't want to stay running, I had to step in and mess with it. There was fuel all over the hsn. The fuel lines were worn badly so I replaced them.

I started it up and it spat fuel out the exhaust pipe (then the fuel would load up and kill it). I tried to lean it out. Leaner and leaner the same thing. It was down so lean it didn't want to start or stay running at all.

I reset the hsn to 1 and 1/2 turns out. It ran but it still was rich and spat fuel out the exhaust.

Then it seemed like the glow plug died. If I took the igniter off, it would die. I changed the glow plug and that glow plug started doing the same thing. I think when too much fuel collects on the glow plug, it acts like a dead plug. I replaced the orginal plug and it seems to be ok for a little while before doing the same thing.

Now, I think I've killed the one way bearing because I can't turn the engine over, it just spins.

Anyway, before I killed it, it seemed like it was getting too much fuel no matter what I did. Is it possible for the pressure from the exhaust to push too much fuel out the tank and through the carb and overdrive the HSN?

I did also lean the lsn quite a bit too.

Has anyone had a problem with their nitro getting too much fuel (way too much) and was unable to control it with the needles?
 
ok one did you hook the lines up correctly it happens i hooked them up b4 .. try setting the high speed at 2 1/2 turns out for all way in and set the lsn flush with the arm ..

Also since one way spins ya probley cooked up but try taking glow plug out and turning it over if it will then ya just possibly hydro locked it

just ideas off top of head
 
Usually raw fuel spitting out of the exhaust is a sign of a way rich setting. But if your needle settings are really as lean as you say, there must be another problem. I don't think the system can provide so much pressure that you're overly rich no matter what. I would take the carb off and clean it thoroughly just to make sure there's nothing that's hampering with the fuel flow. Gently uncrew the HSN to see if it's mashed or nicked or something. Also check the HSN seat in the carb. If it got tightened down too much, it may have expanded the opening allowing more fuel. These are just a few random thoughts. But a place to start.
 
you could also try cleaning the air filter if it is too dirty then it will not let the air get through
 
did you ever check ur lsn? lean that out.. the motor can get alot of fuel from there... even though the hsn is really cranked down...
 
yeah I did turn the lsn quite a bit (a turn or so down).

robd, I'm pretty sure I hooked em up right. :D the exhaust I put on top of the tank and the carb I put on the bottom. It had the same problem before I changed the lines but I think with a more air tight system I just ampllified it. Also, I can turn it over with the flywheel so she's not hydro locked. I'm just going to take the back plate off again and see if the one way is cooked.

Candman, good ideas about the HSN. I'll check out the hsn and if that seems ok, I'll move onto the carb. Like I said, it ran too rich from day 1 and I can't lean it out it must be something deaper.

The air filter is in bad shape and there is no fuel filter on it. It could very will be that something got sucked in.

don't you just love it when you buy someone elses problems? o_O I swear I'll never buy used again.
 
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