[Bigshow6522]

this engine runs well prop size is correct valves are not stuck but it seems realy sluggish in the air . I have it installed in a 300 extra so there should be no problem with itpulling it around the air. It should just jump up into the air. when the prop is turned by hand there is very little resistance in the compression dept so if any one has any ideas on what the potential issue may be i would gladly entertain them.

[williame3590]

Try adjusting the valves first and see what happens. They have likely never been adjusted since new and the 80 is an old engine.

Bill

[Bigshow6522]

thanks Bill on it now

[williame3590]

Well, what is the outcome Kevin?

Bill

[Bigshow6522]

hmmm adjusted the valves made some difference , originally i had a 12x6 prop and was only getting 6.5k rpms out of it ,then i thought try a smaller prop so i went down to a 10x6 and it wouldnt even move the plane on the ground so still stumpped. dont belive i should go to a 12 x 8 or 13 .... any thoughts?

[kip51035]

Put your ear up to the exhaust pipe, then the intake, then the case breather and find where the compression is going. If it is an dirty exhaust valve, you pretty well have to remove it and clean the carbon off it and the seat. If it is coming out the breather, the ring is stuck. As a first remedy put lots of automatic transmission oil inside the engine. Some times you can remove a chip of carbon off the exhaust valve by depressing it and picking it off with a small screw driver.

[williame3590]

If you want to throw it in the mail, I'll go over it and send it back no charge.
You pay the shipping that's all.

Bill