I've got a Saito 1.50 mounted inverted in a H9 Showtime. I've got it set up with an APC 17x4W on 30% heli fuel with a Perry oscilating pump due to the tank being mounted close to the CG. It runs flawlessley with a very dependable idle, good transition and a top end around 9200 rpm. It's got about 4 gallons of fuel through it and I've set the low end needle valve according to the manual. The problem that I can't seem to solve is the presence of large amounts of raw fuel on the firewall and exterior of the plane (top and bottom) after a flight. It's enough that it actually pools on the cylinder cooling fins, engine, mount top and bottom of the plane. In the attached picture the mount is noticibly wet with fuel. I've replace all of the tubing (in case there was a pin hole somewhere) and replaced the o-ring in the pump. The pump is also turned all the way down. I've tried running without the pump but fuel draw becomes an issue and the transition for idle to fuel speed falters. When it is running on the ground there is no noticible fuel spray from anywhere. I'm thinking that it's fuel spray coming out of the carb despite it having a stack and the fact that the fuel is EVERYWHERE afterwards not just around the exhaust. It actually builds up a pool along top edge of the firewall by the end of a flight. Never seen or experienced anything like it. HELP!?

Thanks in advance!

Crash

It's most likely coming from the front bearing?

What about your crankcase vent? Do you have a long tube on it? I don't see a tube on it at all. The oil could be coming from the vent hole in the back plate?

It doesn't seem to be coming from the front bearing as the back of the spinner is relatively dry. I don't have a tube on crankcase vent on this or my other Saitos. I'll do that and see what happens.

Thanks

That is most likely where the oil is coming from. A vent tube should take the stuff to where ever your route it.

Yep, most Saitos spew *lots* of oil out the crankcase breather so you really do need to plumb that mess outside the cowl with some tubing.

Your velocity stack shuld prevent a lot of "spit back" which could be your one of our sources of extra oil all over the place. A lot of people do not realize there is an 0-ring between the velocity stack and the carb, need to close up that space. Other folks have resorted to using air filters that also prevent spit back. And finally, I figure you have an tube extension on the crankcase vent. Several inches of tubing firmly fixed so the tube does not flop all over the place. I have seen guys have up to 10 inches on that vent and it is strapped to the landing gear with a tie wrap.

Cheers,

Chip