rototiller1

Ok, I was running down the road at 100 mph or so, tach was at 6500, when I slowed down to 70 mph it started to cut out , like I was on one rotor. I gave it more gas and it was on two again. Now its hard to start, one rotor is dead at idle, but if I step on it when the secondaries open, its good again. I did a compression check both are at 60 psi, the gauge leaks , all the plug are firing , any ideas? Its a 12a 1985

wwilliam54

apex seal springs are flat

Project84

or broken seals. Your compression test shows 60 psi on all 3 sides of both rotors?

When you say the gauge leaks, where is it leaking from? You should open or remove the check valve so that it doesn't hold a reading like it would for a piston engine. You want the pressure to release so that it will take a reading on all three sides of the rotor. If it held pressure, then you would get a reading, and if the next reading was higher, the gauge would go up, but if the next one was lower, it would not go down to indicate what that lower number is.

Anyway, 60psi is low. 120s it factory, and I don't think you want it any lower then 85psi. The front and back shouldn't be more than 21psi apart from each other.

rototiller1

The gauge leaks at the coupling to the gauge, its a guick disconnect type and the reading I got was on all
sides of the rotors. But I believe I found the problem. I removed the intake and found that one of the plugs I installed after removing the rats nest was missing. This port goes right into the secondary intake runner, so I believe that the rear rotor was so lean it could not support combustion. It was drawing air through there when the secondaries were closed, hence leaning out the mixture being supplied by the primaries

rototiller1

Guy's, that was the problem.