alpinestar

Hi everyone
I'm a long time "planker" and have been getting into helis over the past couple years, with a T-rex and a second-hand Sceadu. I put an OS37 in it, and a Mac's muffler
Here's a link to the muffler I'm using:
http://www3.towerhobbies.com/cgi-bin...p?&I=LXWP31&P=

I have added the upgraded fan from Hirobo, and a homemade shroud around the engine.
So the problem I'm having is an inability to tune this thing. Not new to engines, but this setup seems touchy from no-power rich to running too hot. I've tried both Omega 10% and CY 30% with the same results. Using OS #8 plugs. I'm also using a GV-1 governer to take the headaches out of the throttle curve. Headspeed between 1600 and 1900 depending on the condition.

Is the engine/pipe combo adding to my problems? considering buying a better pipe if it would help.
Is this heli a known engine-cooker? I've done all I can to improve the cooling. Dump it & use my stuff in a raptor 30?
I'd rather be flying than fixing!!
Thanks for the help.

BarracudaHockey

My Feedback: (11)

Not sure about the muffler but if it doesn't have sufficent volume for the 37 it will make it run hot. The Hatori SAB6RS is the best muffler for that engine but it aint cheap.

Also make sure you have good clunk and fuel lines and you aren't getting an airleak somewhere. That engine shouldnt be that touchy, though you will have to richen it up atleast a half turn going to 30 percent. Coolin isn't an issue on the EVO.

alpinestar

thanks 'cuda. It's an old sceadu, not an evo.
The lines & clunk are all new as I changed the tank for the larger one that Hirobo has.
The muffler I'm using is really marketed for the OS32; maybe it is just too small for the 37.
I'm looking for a used Hatori cause you're right; they're pricey!

BarracudaHockey

My Feedback: (11)

Yea that muffler is way too small for a 37, that thing needs some expansion room to make good power and not overheat.