Motors Nitro thunder pro 39h

[Adam]

So i have probably burned up an quarter of a gallon of fuel in this engine. I have now burned up a second muffler lol can not be re assembled. I will be getting an performance muffler for this finally. The problem im having is tuning this engine. I had club members help and man were they wrong. The engine was running so hot it wasnt even funny. As of now i am taking the gov off and getting it problem free first once that headache is done i will put it back into play. It runs great and there is no blackening on the piston so i am not damaging the engine yet but i am hoping to not give up on this thing. P.S. i wish i bought electric.
Struggling nitro fan

 

[Tony]

The piston getting dark is good. If you are not getting any color on the piston, then it's very lean and running rich. Now, I'm not saying it should blacken the piston, but it will change it a darker color.

When you put the new pipe on it, set the needles back to factory and start over. good luck.

 

[coolgabsi]

check your ring.. if its shiny metallic chrome color , its BURNT! That piston ring needs to be black in color..

If the engine ran too hot.. like you said.. it probably took the damage somewhere. You say burn tmuffler... ? I dont understand.. what happened?

Tuning.. like tony said, even if its going to be extremely rich, go for stock needle settings. remember this is not an airplane engine and CNNOT be tuned on the ground. NEVER can a heli engine be tuned just sitting on the ground.. it doesnt have a prop on it as load and you can spool it up on the ground to check the laods and pick it up and all like you do on a plane. Even put the idle needle at stock position.

ok .. then you go in two clicks at a time.. doing pitch pumps and then going negative pitch to make it fall fast.. and then again a couple times.. everytime looking for signs of leaning out engine or screaming engine. .

chekc the temps after 2-3 mins of flying and it should never go over 180F. You only have the high needle so tuning should be easier..

 

[Adam]

I will have to take a picture lol. from the heat my muffler loosens up.....the muffler itself not where it is connected to the motor. the stock muffler is a three piece system and is like 12 bucks for new lol I'm getting an muffler upgrade.

 

[coolgabsi]

I will have to take a picture lol. from the heat my muffler loosens up.....the muffler itself not where it is connected to the motor. the stock muffler is a three piece system and is like 12 bucks for new lol I'm getting an muffler upgrade.

Once you have the muffler rebuilt. Use primatex ultra black.. A thin layer of it to make a seal, and make sure it's not leaking and won't come undone. That's how my engine is right now.

I had a major exhaust leak, and I yes my nylock were melting cause of it. Now no melting no loose muffler just a good running engine
Me careful with that primatex stuff a thin thin layer .. Clean surfaces with alcohol before

Fly safe!! have fun!

 

[Tony]

If this is one of those mufflers that has a bolt running through it, use red thread locker on that bolt ONLY. There is a Great Planes manual that states to use it on those mufflers.

As stated, forget about the gasket and use a gasket maker like permatex. Black is good, but you can use orange/red if you dont' have the black. VERY thin. Keep dabbing it until you think it's less than enough, then dab it some more. The gasket will collapse causing the bolts to come loose. If you use a gasket maker, there is nothing to collapse. I won't be running a gasket on the 600 when I get the new engine.

 

[coolgabsi]

yeah tony.. as you probably saw.. I also threw the one I had away and going with the permatex ultra stuff.


BTW(totally off topic) I changed the bearings on my 91 today. Muffler is a bit iffy but I am sure you can help me get it to fit. Might have to order a gasket or two to seal the engine properly on the carb side. once I have it all.. and you give me a green light. I ca ship you the shhhtuff..

 

[Tony]

I'm happy to do it any time, but after this week, it could take a while.

 

[coolgabsi]

its ok... it probably wont be this week .. so its ok. I have waited long no hurries