I have a moki 1.8 that is real touchy. I cannot keep this thing runniing for more than a flight.

When I tune it up so it will idle and transition it will burn up every sort of plug I have put in it in a flight or two. I have use ho plugs to cold to four stroke plugs.

Has anyone out there had problems with this engine adjusting it or with fuel or plugs. What did you do to make this stupid thing run?

Need more info!!!!

here's the scoop.
1. use large fuel line throughout system.
2. use ONLY 0% or 5% moki blend fuel. This engine does not like anything higher!
3. breakin is a long process. What sounds perfect on the ground is too lean in the air. motor will need to run rich for many gallons.
4. What prop. breakin in should be an 18x10.(see #3) After that then you can experiment a little but watch the rpm.

Hope this helps

I run 5% nitro
sig I think off hand

18-8 prop

engine has about 4 gallons through it

How tightly coweled is the engine? Have you tried an OS#8 plug yet? The prop is the right size; make sure you're running it really rich - it should have a good smoke trail behind it on the ground.

The engine is not tightly cowled I had good airflow going in on my extra 300 and atleast 4 or more times as much going out.

I have run os #8 plugs and the effect was the same.

So far all I have gathered was that maybe it was running too lean?

Are you using 5/32" fuel line and have you drilled out your clunk? Here is a related thread: http://www.rcuniverse.com/showthread...98&forumid=145

Dalee

The only time I have really gone through glow plugs was when I was trying to run too large of a prop on a 45 size engine. Running an engine lean will encourage heat build up and fry you r glow plug. These engines love to run really rich. I don't lean for max power with my Moki; I tune it so it is running strong with plenty of smoke coming out. In the air you should see a slight contrail, like when watching a YS140 fly. I am running standard fuel tubing with mine and have a Perry pump as well.

sounds like that fuel line suggestion is a good start

I had the same problems and changed my plug to OS F type, and installed a perry pump, and swinging an 18X8 prop. No more problems. The F type plug is listed for 4 stroke, but it is a hot plug which is needed when burning low nitro. The perry pump deliverys more than enough fuel. Need not worry about leaning out in the air once its set up correctly.
Hope this helps.

I like the pump idea I will go with that and see what happens.

Up till now nothing else has worked.

What type of muffler are you using? Burning plugs can also mean you have too much backpressure in your exhaust system, or, if you are using a tuned pipe, the pipe is too short.

In any case fried glow plugs tell you that the temperature at the cylinder head is too high!

I have a slimline large volume pitts muffler w/ smoke.


I have come to the determination that I was just running my engine too lean, and that is the root of my problems.