Motor has to much compression!

[tempest]

hey all

I am running OS MAX SX H C SPEC+ Viperhead and cool Power 12.5% nitro. Shims: 1/ 0.08 and 1/ 0.04

I start my Heli with a drill press (Is stronger than my 90 starter)

sometimes my Motor turns like butter! But today (again) i could not even turn the Motor by Hand!! It had a really big compression. Even the drill press had no chance to turn my Motor. What could that be?

Is it because to much fuel is running in my Motor? 2.5 turns on my Needle (I am still breaking in) Is that normal for a motor?

yesterday i took a glow plug out and turned the motor! (It was full with Fuel) After that it was much better! I filled up my Tank and try ed to start again! It had that hard compression again!

I saw that fuel in the fuel connection from the tank to the muffler was! Could that cause that high compression?

Thanks for help!

Andrew

[WayneBrown]

It sounds like you are overfilling a bit, and dumping fuel into the muffler where it backs up into the combustion chamber.
You can bend a connecting rod if you are not careful!
Remove the line to the muffler when you fuel your machine, and leave the drill press away from the helicopter.
The shim amount seems too small, but I don't run OS, and will leave that for someone more familiar with the motor to comment on.

When the motor seems especially tight, lean it towards the muffler, and the tail and try to turn the starter shaft by hand, this seems to clear a lot of the excess fuel out of the combustion chamber.

[tempest]

Well the shims should be right. everything under 15% nitro needs 1/0.08 and 1/0.04. For 15-30% is 2/0.08 shims needed.

tomorrow i will fuel up with no connection to the motor.

Hope it works!

THX

Andrew

[tempest]

I just take a glow plug out and there was really a bit to much fuel in it. The connections are of and closed.

the motor is like butter now! I will go test tomorrow and let you now if it works.

Andrew

[flyinfool]

If you fill the tank with the line connected to the engine and let it alone for a while the fuel will drain from the tank into the engine and cause the problem you are having.

It also helps to not stop the engine by radio command.
Close the fuel line or pull the line from the engine to stop it. This will remove the excess fuel from running rich and make the next start easier.

[tempest]

well i did fill my tank at home up and at the field it was hard like stone to turn the OS!

I will try it today and let you now if it works!

Andrew

[Kinger]

Not sure if this will help, but when you finish a flight, pinch off the fuel line and let the engine run dry. Then on the next flight, light up your glow plug, start spinning the engine and THEN release the fuel line.

[tempest]

I was flying today and it worked fine!! But there is a nother problem!! When i Hover there is a strange sound! Really high screaming sound! But that is only in Hover! On idle up 2 it works fine!

I did a Video! So i will cut the part of the Hover out.

Andrew