Issues with Moki 180 high end revs cutting out

[jkberry]

All
I bought a second hand older pattern plane which has a Moki 180 with cline regulator and crankcase pressure. I bought the new gaskets for the regulator and new needle and O ring etc. When I go to start the plane alot of fuel leaks from the carbi. I am not sure if this is normal and it seems to idle up to mid revs. When I attempt high revs it drops out and I cannot understand why. There is not a great deal of adjustment on the Moki. Can anyone give me any further ideas

[rdgood]

jkberry,

It sounds like you may be overpressurized. If fuel is spewing out during start up. If the pressure is to high does it behave rich at hi throttle? Could be a plug issue at the top end also?

Just some ideas...

Ronster

[JoeAirPort]

Been there. Your metering needle in the Cline likely has some dirt lodged in it and it's keeping it open. You need to flush it out or take it apart and clean it. It's not supposed to leak out of the carb. What's happening is the pressure that you are building in the tank is bleeding through the stuck open metering needle. Hence the gas leaking out of the carb. Your engine can't digest all that fuel after building tank pressure and probably floods out and dies. The way the Cline works is on demand. If the engine doesn't suck fuel, no fuel comes out of the Cline. As soon as the engine sucks fuel the Cline will open that needle to deliver the perfect amount of fuel. They are awesome devices.

PS: I'm assuming you have it plumbed correctly.
PSS: Bill Cline told me a good way to flush it. Just attach a fuel filling pump to the outlet of the regulator and suck fuel out of it. After a bunch of cranks it can get the dirt out. If that doesn't do it, take it apart.

[TazmanianDevil]

The head of the engine is straight up or down ?

What kind of plug are you using ?

[jkberry]

HI all thanks for your responses appreciated. I have cleaned out the regulator and put it back together with a new diaphram. This didn't seem to work as there is still a steady stream of fuel from the Carby. The engine is inverted. Also I am using on OS 8 Four stroke plug.

[JoeAirPort]

Well then you need to send it back to Bill Cline. He'll either fix it or replace it...likely for free. Those things are not cheap but the guy supports them like they are his children...and actually they are. You should not be seeing ANY fuel at all coming out of the carby when the plane is just sitting there. The only way that's possible is to have a regulator that's has a leaky metering needle. I had the same situation and couldn't get it to stop leaking. Bill Cline fixed it and sent it back for free. He's great.

If it only leaks out of the carb because it's flooding, you might want to make sure your glow plug is good and that your glow driver is fully charged...so the plug is getting hot enough. Also make sure your needles aren't too rich.

But if it just keeps leaking through carb, and never stops when the engine is off, then the Cline is the problem.

[zx32tt]

As I recall, the is a check valve in this system. Make sure it is installed, and functioning properly. Give Bill a call, he can help you sort it out.
zx32tt

[JoeAirPort]

The check valve would cause it to not build enough pressure in the tank. It would not cause the fuel leaking....but good call to consider the check valve. I forgot about that.