Thanks for checking out this thread. I have been having trouble getting my Moki 1.8 to run consistently. Here is the poop:
The Setup:
1. Moki 1.8 with one gallon of fuel through it.
2. Bisson "sport" muffler with muffler pressure.
3. K&B 1L glow plug as recommended in manual.
4. Fuel: Byrons FAI castor/synthetic blend.
5. Airframe: Morris Giant Su-do-khoi.
Symptoms:
I would have to set the high-end very rich on take-off to avoid sagging during vertical manuevers later in the flight. During take-off I would sometimes not have a clean two-stroke it was so rich. It would break into a clean two stroke during verticals early the flight if pulled to the vertical. As the tank burned down I was able to get a clean high-end in level and vertical flight. At first I just thought this was "new" or "tight" engine behavior. However, after a gallon of fuel it has not changed at all.
My Guess:
The engine had a fuel feed problem resulting in inconsistent mixture as the fuel tank level decreased. I had thought that this was improbable because of the excellent placement of
the fuel tank. It is directly opposite the engine and exactly on the centerline of the carb. See my website at
http://home.flash.net/~jecramer/giant_su_do_khoi.htm for the engine/tank arrangement. I can't imagine it getting any better than this!
Solution:
I mounted a Perry VP-30 regulating pump using crankcase pressure.
Results:
Horrible. At first I could not get the engine started because of the amount of fuel the pump was supplying at idle - it was really flooding. I leaned the idle, got it started, but could not transition past 1/4 throttle due to fuel starvation. All combinations of high-end, low-end, and pump volume adjustments were tried but nothing would provide a consitent run. I either could not start it because of the excessively rich low end, or I could start it after leaning the low end but could not transition to a high-end.
Suggestions?
Try a Cline pump as recommended in the manual?
Go back to muffler pressure and try different glow plug or fuel?
Sell it on Ebay and get a gasoline engine?
All advice is welcome! Thanks!