OS50 need to run "rich"

[Rockohaulic]

So we're flying the Hurrican the other day, and the engine is not running smoothly (OS50 Hyper with MP5). There is a hesitation, or tick, followed by the tail moving. I'm thinking I should richen it up a bit, and the guys at the field concur.

I richen a few clicks. Still not smooth. A few clicks more, and that seems to do the trick. Later I notice that I am at about 2 1/4 turns out on the needle! That is a lot more than any of my other helis.

Does that sound right to you guys? Why would I need it to run so rich?

I checked the temp several times, and it is 109 at the backplate, and in the 190's to 200 deg at the head. This also seemed strange. Not the 109 part, but the head temp seemed a bit high for a 109 at the backplate. I've seen 170 at the head with a 109 or 110 at the backplate on other helis.

What do you guys think?

[chase]

I dont know about the differance in the head and back plate. But here in okc with our weather 2 and a 1/4 is about right. But its hard to say because it depends on you sea level, humidity ect ect.

[helibrite]

I think you'll find the Mp-5 to run a bit richer than the other Mp-2. I run my motors around 2-2.25 turns out and the head temp around 200-215 degrees. Rusty