High Speed Stalling

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only-half-evil

Gone - bye bye.
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Pennsyltucky
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  1. Bashing
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I got an older T-Maxx with the 2.5 engine in it. Its all factory...for now. It sat for almost a year without being ran. For a bit...I couldnt get it to start. Ended up starting the tuning from scratch...and going with a 3 1/2 on the hsn and 1 3/4 on the lsn. Finally got it to start...but would only start without the air filter on...which is a new filter with fresh oil in it...and you gotta turn the idle way up for it to start and stay running. Once it starts, I turn the idle down and it idles just fine. Once I got it first started...I did some slow runs...it was just fine. Did a few fast runs...and it was fine. A few laps later...when you get on the gas...it stalls right before hitting 2nd gear. Any ideas on what it might be...and how to make it stop doing that? I'm newish to nitro...I'm more a 2-stroke person. So any advice would be very helpful. Thanks.
 
Got an older T-Maxx with the 2.5. It sat for about a year. Tuned it and got it running. 3 1/2 on the HSN and 1 3/4 on the LSN. Itll only run without the air filter on...with is a brand new one...and now it stalls out right before 2nd gear when you're on the gas. Any ideas on the cause and how I can fix it? All advice is appreciated. Thanks.
 
Nitro engines are 2 strokes. Richen your high speed needle a more.
 
Thanks...Ill give that a try. And I understand that they are 2-stroke engines...but they aret the same as regular gas engines. Theyre way more finicky.
 
Loo start my puting the air filter back on. It's crucial. High speed stalling is usually from the hsn being too lean. Richen it up till it starts to bog and then back it out 1/8 turn
 
Thanks...Ill give that a try. And I understand that they are 2-stroke engines...but they aret the same as regular gas engines. Theyre way more finicky.

They have almost nothing in common with a regular gas engine
 
They have almost nothing in common with a regular gas engine

I think he meant "aren't". But other than the fuel, they are very much in common with diesel engines. They dont have valves, and are 2 stroke, but rely on heat of compression to ignite the fuel instead of a spark plug firing. And if you think about it they have alot in common with gas engines. Really the only thing that is truly different about them is the lack of valves (2 stroke) and a spark plug, and of course the fuel they run on, which I believe is much less volatile than gasoline and diesel I believe.
 
I richened it up...now itll hit 2nd...but now it stalls when you let off the gas or hit the break. Its not the idle speed cuz itll do it even with the idle way up
 
Diesel engines have valves, even the 2 stroke diesels.

The way in which a nitro engine fires is the only real similarity to a diesel, but diesels rely entirely on compression, while a nitro needs the residual heat and catalytic reaction of platinum on the glow plug along with compression to fire.

Nitro engines are more like 2 cycle gas engines IMO, but the fuel/air mix travels through the crank and is forced up through the sleeve by the pressure of a downward moving piston.

O.H.E., in my opinion you should start by richening the high speed needle 1/2 a turn, but I think you may have other issues as well. I'd check the engine out to see if it's worn or leaky.
 
I cranked up the richness...now I can hit 2nd and high speed with no problems. But now when I get done hammering the gas and let off totally...it stalls. Even had the idle speed way up and itll still stall if I completely let off the gas.
 
Adjust your throttle linkage it sounds like the carb is closing off when you let off the throttle. There should be a constant .7 to 1mm gap when the throttle is in the nuetral position or when the brakes are applied.
 
Did not know that. Gonna have to try it...but wont know for sure until sometime tomorrow. Was out running it and got a bit too close to my patio. Snapped a few pieces that I dont have spares for...and am not gonna pilfer from my E-Maxx.

---------- Post added at 8:55 PM ---------- Previous post was at 8:53 PM ----------

But wait...there is a gap on the slide when zeroed out...it doesn't close fully.
 
Turn on the electrics pull the air filter off and look down the throat of the carb. Apply the brakes if the slide moves and closes the gap then adjust your linkage accordingly. If it doesn't you may try leaning the low speed needle a little. You should always set the idle gap with the brakes applied. That way you know for sure the slide is not closing off when you hit the brakes or when you let off the trigger.
 
Check the clutch spring, dieing when the brakes are applied & wheels turning on start up are a sign of a clutch problem.
 
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Use a small paper clip to set the gap, then adjust the low needle to flush, or about 1.75 turns out.

Once the low needle is set you may still have to lean it just a tiny bit until it idles for at least 15 seconds when warmed up.
 
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Ill check it...but the wheels dont turn on start-up...but I do have to throttle it to get it to start
 
Multiple threads by thread starter merged.
 
I didn't think you said anything about the wheels turning on startup. I do think you need to keep leaning the low speed needle.....in very small increments.
 
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