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Bikersurgeon · 05-21-2013, 06:58 PM

Sort of a multi question: noticed my nitro heli was running a little lean, could not richen it at all with the needle. Fuel lines fine, no tank leaks, etc etc. long story short the muffler nipple for the pressure line was very loose and the gasket under the nipple had disintegrated. The threads were rough so I was considering JB welding it in place. Bad idea? Will the 5 minute JB stand the heat? Would this actually be the source of my problem? Been a long time but I seem to remember that even muffler air leaks cause a lean run (less tank pressure=less fuel delivery) Thanks in advance.

RogerRabit · 05-22-2013, 12:17 AM

I use loctite red on that.
It does not hold perfect because of the heat but it is enough so it does not come lose.

The alternative is 24hr epoxy. that is fairly heat resistant.

I heard on some people soldering the pin also on alu mufflers, but i never tried that yet.

Bikersurgeon · 05-22-2013, 07:41 AM

cool, thanks, Roger

marc8090 · 05-22-2013, 09:31 PM

JB Weld for the pressure nipple in the muffler works great.

koppterx · 05-23-2013, 07:17 PM

if the gasket was leaking there should be residue around the nipple, which would reduce pressure. i have my doubts that even it was loose, it would reduce it so much that the needle would not go rich, but it's a possibility. i'm more inclined to think that the problem is something loose on the engine that is sucking air, and the first thing i would check would be the needle valve assembly. it the engine is running really lean - as in an air leak, it would also be blowing plugs pretty much every flight. nipple without a gasket work just fine as the threads seat the nipple.

05-21-2013, 06:58 PM	#1 (permalink)
Bikersurgeon Registered Users My HF Map location Join Date: Dec 2011	Nitro air leak Sort of a multi question: noticed my nitro heli was running a little lean, could not richen it at all with the needle. Fuel lines fine, no tank leaks, etc etc. long story short the muffler nipple for the pressure line was very loose and the gasket under the nipple had disintegrated. The threads were rough so I was considering JB welding it in place. Bad idea? Will the 5 minute JB stand the heat? Would this actually be the source of my problem? Been a long time but I seem to remember that even muffler air leaks cause a lean run (less tank pressure=less fuel delivery) Thanks in advance. __________________ AE .50 apache, TT .90 TOW MD500, 2 x JR ergo 60, TT x50 titan, TT 50, TT 30, 3 x MTe325, MSH Mini protos, trex 450 Apache, MT cobra, Airwolf 450, Blade 400, century 50 Bell 47, MT EC135, RADIKAL G20, trex450 MD500, Protos 500

05-22-2013, 07:41 AM	#3 (permalink)
Bikersurgeon Registered Users Thread Starter My HF Map location Join Date: Dec 2011	cool, thanks, Roger __________________ AE .50 apache, TT .90 TOW MD500, 2 x JR ergo 60, TT x50 titan, TT 50, TT 30, 3 x MTe325, MSH Mini protos, trex 450 Apache, MT cobra, Airwolf 450, Blade 400, century 50 Bell 47, MT EC135, RADIKAL G20, trex450 MD500, Protos 500

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05-22-2013, 12:17 AM	#2 (permalink)
RogerRabit Registered Users Join Date: Aug 2012	I use loctite red on that. It does not hold perfect because of the heat but it is enough so it does not come lose. The alternative is 24hr epoxy. that is fairly heat resistant. I heard on some people soldering the pin also on alu mufflers, but i never tried that yet.

05-22-2013, 09:31 PM	#4 (permalink)
marc8090 Registered Users Join Date: Sep 2006	JB Weld for the pressure nipple in the muffler works great.

05-23-2013, 07:17 PM	#5 (permalink)
koppterx Registered Users Join Date: Jul 2008	if the gasket was leaking there should be residue around the nipple, which would reduce pressure. i have my doubts that even it was loose, it would reduce it so much that the needle would not go rich, but it's a possibility. i'm more inclined to think that the problem is something loose on the engine that is sucking air, and the first thing i would check would be the needle valve assembly. it the engine is running really lean - as in an air leak, it would also be blowing plugs pretty much every flight. nipple without a gasket work just fine as the threads seat the nipple.

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