Hi Dave;

I have a YS91AC that I have been running on & off for the past 2 yrs. with no problems what so ever other than a little harder starting when it hasn't been run for a while. It had been about 3 months since I had flown the plane that this engine is in. I flew it last week with absolutely no problems. Yesterday I tried to start it & I got absolutely nothing using the usual procedures of the past. It typically starts inverted in a Runaway. I checked my fuel turned the plane so that the engine was upright & tried the same usual procedures, nothing. The first time that I ran this engine after getting it used I had to prime it thru the carburator. I did that & it started with a touch of the electric starter, however it isn't getting any other fuel beyond the prime that I put in the carb & stops running as soon as that is gone. I am a real novice with YS & the inner workings. Any help would be greatly appreciated.

Thanks,

Ken

Since the the engine has sat unused periodically, it probably needs gaskets, seals and a regulator re-build. Check to see that the check valve is working properly and that the tank is pressurizing. Make sure the plumbing is right. Reversing the fuel/pressure lines will cause this problem.

Contact YS Service at 775-782-4562 and talk with Richard, he will advise what to do and get you the parts you require.