I'm a little nervous about the stock tank location and my inverted Saito 1.80. I ran the engine on a test stand yesterday with the small test tank centered on the crank and the engine inverted, just like it will be in the plane, and it was siphoning fuel and flooding the carb. I disconnected the pressure hose from the muffler and managed to get it started, ( one flip after it spit all the fuel out of the carb) so I'm worried. I did notice afterwards that, due to the smaller tank on the test stand, the clunk was quite a bit higher than the carb. I checked out the stock tank, and it looks like the clunk will end up almost level with or slightly above the carb. I'm going to re-mount the test tank to put the clunk at this level and see if it helps.
Anyone who has put an inverted 4 stroke in this plane with the stock tank location, please chime in and let me know how it all worked out. Did you need to lean it alot? Did anyone need to use a regulator? Has anyone tried to lower the tank?(I don't know if I trust myself to try this...I can't even see in there) Randy