I just bought a used Moki 180 and it runs fine, but seems to vibrate more than it should. I have had other Mokis, a 180 and a 210 that do not vibrate as badly.

The APC 18x6W prop is balanced, and I have tried other props with no improvement. The engine is mounted as close to the firewall as it will go, on a Great Planes black plastic 180 size mount and uses a Bisson Pitts muffler. It is running on 5% Omega with a K&B 1L plug and it is tuned to transition smoothly and run up to 100 rpm below peak. Changing the plug did not help either.

What is your experience with vibration in the Moki 180, and what if anything did you do to smooth it out? Any Ideas would be appreciated.

Jim

It may have a bad bearing?

Are you sure the crank isn't bent a bit or the drive washer tweaked some?

The bearings are Ok. I will check the crank and drive washer.

Thanks,
Jim

Try a slightly unbalanced prop, and line up the heavy blade with the crank counterweight (at TDC, the counteweight will be at the bottom of the engine).

Cutaway:

Ihave used that trick very successfully to balance cheap electric motors. Iwas hesitant to use it on the Moki because... well... Iguess the size and power intimidate me.

And that is, after all, a crutch. Isuspect that my solution is going to be replacing the Moki with an OS 1.60.

Jim

Try no NITRO with a OS Max "f" glow plug. These engines do not need Nitro.