I have one of those IR thermometers with the laser pointer, but I'm not sure where I should be measuring engine temp. Obviously it's hottest around the exhaust port, but I'm not sure that's where I should measure temp.

On a related note. I have a Raptor 30 with a TT36 in it. The engine seems to consistently lean out, overheat and lose RPMs after about a half tank. I've been frustrated trying to get just the right idle and high end mixture. I'm guessing it has something to do with lack of muffler pressure to the tank, but I'm not sure. I have one of the TT shiny aluminum pipes.

If I fly around for a while (5-7 minutes) and land with a half tank and go to idle for over 15 seconds, if I try to spool back up it dies abruptly at about half throttle. Right after quitting, the exhaust port / crank case temp measured about 210 - 220. This seems hot, but if I richen the low end it won't idle.

Fuel is Omega 30%

Jason

i have the TT39. had similar problems, untill i got the needles set right, then of course the temperature here got a lot higher, and i started having problems again. this weekend i tried something drastic, i modified the idle needle, now it is a sweetie again. the mod is to grind a conical section on the end of the needle about 0.060 long and down to 0.030 diameter at the tip. i think what i did is get the carb to have smaller overlap between the idle needle and the high speed needle. but truthfully all i know for sure is it is running better than it ever did. i read a thread recently where a few people tried different variations of that mod. It almost seems like anything you do to the idle needle that makes it smaller works wonders, (hit it with a hammer = bad, grind it down with a file,=good) maybe the 36 carb is the same?


i measure temp around the cylinder not the head. When breaking in i tried to keep it under 200, now i run around 220-240. i don't see why you should have shut down problems under 270 degrees though. maybe try a new plug first?

If you can get that TT36 to run, you're one up on me. I tried and tried to get my settings right, but couldn't get it after many evenings of 2 minute runs. Spiff may have figured it out by modifying the needle.

I sold mine cheap, got an OS32. It starts and runs just about perfect every time. VERY reliable. From the threads here, they say the TT39 is very good too, and more powerful.

I don't remember where it was, either here or runryder.com might be a good idea to run a search and see what others did. you can get replacement needles so you can experiment to your hearts content and still be able to get back to where you started if need be.

I was just flying again today, man it was running great! i wish the same for both of you.

Spaceman, I don't think I have the tools to do the needle modification you describe. I guess I'll have to run it rich until it heats up. I just hate all the excess smoke. That stuff is like tear gas if blows towards me.

Jason

Using IR or laser device, you want to check engine temp from under the heli, point the device at the small area between the bulge for the exhaust bolt and the heatsink head.

Most of the data I have heard is that this should be somewhere below 225 to 230 if you fly around for a while, land and check it relatively quickly. This varies and some people run them hotter, some very cool.

Many folks just check the backplate temp with thier finger (Curtis does this).

I check the temp periodically just to make sure I am not overly lean, if I am spiking 250/260 after flying around and landing, I know I am just a bit lean...

Well, I found part of my problem. The muffler was losening and allowing exhaust to leak out. Therefore, I wasn't getting as much back pressure in the fuel tank. I flew yesterday and after richening a few clicks I started rich (super smoker) and then it leaned to just right after about 5 minutes. Time to tear it down and check everything. I might try another engine I have.

Jason