ORIGINAL: spyder0069

Ok, after reading all the great posts on Moki's I picked one up for my CMP Extra 72". I am running some 5% fai fuel in it and ran about four 24oz tanks on the stand before mounting. I tapped the back and mounted a perry vp-30 and tuned it up. Weighing in at about 13.5lbs and running a Bambula 18x8 wood prop I expected this thing to skyrocket. I am still running a bit rich on the highend but probably only about 5 clicks or to drop about 400 from peak. Well even with the pump there appears to be a change in the ratio as mid flight I am definately blowing less smoke and what is noticably rich at the start is probably right on at mid flight. Not sure why that is happening.

***If you are running muffler pressure, disconnect it. Muffler pressure disables the regulator function in a VP-30 Perry Pump. This would explain the unregulated behavior your engine is displaying.

I do have a pressure bypass system with a T fitting between the pump and the carb with the bypass going back to the tank. I put a zip tie around the bypass to shrink the whole some but fuel can definately flow back through it.

***You don't need all of that return line crap for a large two-stroke. If the Perry Pump is good, its output is adjustable.

The tank is on the cg which is about 8 inches back from its original location. Anyway to make a long story short its not as impressive as I would have thought. I had a GP Giles of the same size and weight with at ST 2300 1.4ci running a 17x6 APC that would pull the plane out of sight. This Moki setup can just barely pull out of a hover.

***If the engine truly is new, it is going to take several gallons of fuel through the engine before it attains full power and good throttling manners. Worrying about minutia on a new ringed engine is pointless. Mount it up on the test stand and start running fuel through the engine before worrying about anything.

My first impression is that the Bambula 18x8 (although being a wide blade) is not the right prop (at least here in Illinois). I have always been dissapointed when trying wood props and always had a noticable difference in power when going with a APC. I am thinking about either my 17x8 APC or the 18X6 Wide APC. I am using a O.S. F plug on the engine. I have a feeling either my pump setup isn't perfect, wrong prop, or something tired about this engine. I did buy as "New" on ebay and indeed the engine had no castor stains on it and the sleeve looked like it had never been run but when I received it the engine was locked. I had to pull it apart to find the crank had rust on it and I had to oven heat it to free up the bearings and then oil it all down. Sleeve all looked new though so I don't know if its possible that it was just old but new or if someone bench ran it, didn't oil it up, and put it away. Brand new compression though. Anyway if anyone has some advice or tricks for these I would love to hear it.