Pumped Motors

[Uncle Jim]

I have the OS91 SZ motor.

What i won't to know is how do i tell if i am running the motor to lean/rich; as i cannot feel the back plate temperture due to the pump being in the way.

The motor is very smokey and oily, which would make me think that it is running rich and it seems to get smokeyer towards the end of the tank. When i say smokey i mean every body comments on how smokey it is?

One other thing what does the regulator do?

[mattie-lodge]

My experience with pumped motors are not good. ESettings change when they feel like it. Pull the pump off and run it normally. You may have to change the carb.


Uncle Jim where do you fly?

[Steve]

Never had a problem with my 91 C-Spec pump. It's well old now, and was 2nd hand when I first got it, so God only knows what it had been through before I had it. It's done hours and hours and hours of flying with me, with no new bearings or anything.

It runs smokey and it runs well. I run it a tad on the rich side just so that works well throughout the range. The chap who I bought it off had never fitted the pump, and had an OS 70 carb on it. He sold me the engine with the original unused carb and the unused pump which I fitted a couple of years ago, and have used through 3 helis now with no problems at all.

[mattie-lodge]

Manager,

Trust me you got a good one