I have a new Moki 2.1 that has over a gallon through it. I am using a APC 22X8 and Bisson sports muffler.and can get 7500 RPM. The problem is at idle it is really rough. As l power up there is a ping ping ping sound untill abut half throttle. Sounds like pre-detination. Sometimes at idle it smooths right out, the way it should be and then starts to get rough again. Is it to rich at the low end. I tried turning it down, but it dies on me. It dies if l richen it as well. I have tried different plugs as well. I am using XP Sport fuel 10% nitro, 20% oil. Any ideas? Let it break in some more? To rich, or lean?

Thanks

Tim

Nitro levels of 10% is high for the Moki . Try lowering it to 5% or get Fai fuel.
One gallon is still not enough . The engine will run better after 4-5 gallons.

I'm breaking mine in with a 20/8 prop. Only 3/4 of a gallon so far. No problems with idle; in fact it will idle so slow it's hard to stop with the kill switch. Your prop sounds to large for break in.

Maybe too much prop, too much nitro, lean low end, I think.

I broke one in on a Mejzlik 20X8, 0% nitro, Cline regulator. It is an excellent engine and uses very little fuel if burning FAI fuel for the power it makes.

I switched to a 20X8 and have the same problem. I have to go with 10%. I cannot find a LHS that will get me FAI fuel. And once they are out of 5%, that's it for the year. They don't sell enough to make it worthwhile. I can order some and have it shipped to me, but here in Canada it is considered dangerous goods and cost more to ship than the price of the fuel. I am sure the problem is in the low end needle. I will clean it out and start from scratch and let you know how it goes.

Tim

Tim, just get the hobby shop to orer you a case (4 gallons) next time they order fuel. It won't take you too long to go thru a case if you fly much.........

Ed M.

go to a go kart or motorcycle shop and buy methanol and the proper oil, castor and synthetic and make your own fuel. While breaking in, I would run half castor, half synthetic with a total of 20% oil and balance methanol

Dont disagree with anything above, the only thing I will add is that these Mokis take an age to run in.

They seem to keep getting better and better yet more docile at idle, I think you get the idea that I reckon they are great

Cheers

Phil

Mokis will overheat and detonate w/ anything over 5% nitro - specially in summer temperatures (ask me how I know )
And 7500 rpm is about the right range for the 2.1, so I don't think that 22X8 is too big a prop. Mine spins an APC 20X10 happily at 7400 rpm with no overheating probs PROVIDED I keep the nitro to 5% or less.

I agree with JeffH. You can mix a gallon of methonal with the 10% you have and that would cut you down to 5% nitro. You would have to add some castor oil to get the oil level back up to 20% but you should not have a problem finding methonal or castor where you are at.

I fly my Moki's on no nitro and 15% oil. The 20x8 prop is a better break in prop for the Moki.

tonyc

Thanks for all of the answers guys and gals.
First of all the first post was a typo. It was a 20/10. Big fingers on the keyboard.
Unfortunately l live in a small town. No methanol and nothing under 10%. Nearest big city is 3 hours away and the two RC shops their will not get me FAI. SO l am stuck with 10%. A buddy in our club uses 10% and he has no probs at all. He tells me the nitro smooths out the mid range and he rarely uses full power. I will rarely need full power either. What else l found though is the carb is leaking fuel from the barrel. I took a new one off of my second MOKI 2.1 and 90% of my problems went away. I occasionally still get a pinging sound. But l think this may be from the way the engine is mounted. The plane is a aero works 300 profile. The engine is mounted between two hardwood mounts. So l am going to brace the mounting points with some aluminum, for a stiffer mount. See if that works.
So the next question is, where can l get Moki parts and/or repair services. I thought it was Gerard Enterprises. But they are no where to be found on the web.


Thanks

I have a Moki 1.80. I removed the piston to change the ring, and now I see there is a tab, in the ring groove to stop the ring from turning. The problem is, I do not know if the tab in the ring groove goes on the intake side port, or the exhaust. Clould someone please help.