i have a 63fz that runs great about half the time. it will be running great then throttle back to slow down then throttle up and the thing lays down till it clears the fuel then runs good. it dont do it all the time. then sometimes when landing it floods out and dies . i have run the valves several times and cleaned the reg. it seems to be a problem with the reg. not seating all the time. i have it set almost bottomed out. thats where it runs the best. then sometimes i get black oil on the side of the plane and its not comming from the muffler it seems to be coming from the carb like the intake valve is not seating all the time. but then sometimes the thing runs like a swiss watch, i have 5 ys engines and this one is kicking my ass. when it runs right it is a beast for its size.. i have been putting off writing you because i can usualy figure these things out i have been wrenching for a living for 30 yrs.lol what do you think
earle

How long has it had a problem? At this point it needs to visit our service dept. Sounds like it may have a bad regulator.

it has been doing this since i have owned it. co you please give me the addy and number for service please?
you have confirmed my suspicion. what would be the chances they can convert it to the s fuel sys.? i have both and it dont look to hard
thanks a bunch

YS Service
1295 Industrial Court
Gardnerville, NV 89410

775-782-4562

They are closed for vacation for the next 2 weeks, wait until the end of next week to send it.

Is YS service completely closed? So you also don't answer mail?
The exhaust pipe of my 110 broke yesterday and I lost the muffler. Is this part of the warranty? If not, are the Ultratrust mufflers a (very) good alternative? I'm thinking of ordering one with a twister elbow. Are these elbows, in stead of a fixed angle elbows, reliable?
I solved the idle problem btw. The engine simply ran too hot in the FL climate with 93 degrees. I adjusted the transition a bit richer and made a big hole in the cowling.
thanks.

I am not in service so I can't help. Richard,(the boss) is out of town so not too much is getting done there. Lots run the PS mufflers, but a fixed elbow is more reliable than the twist type.

what gives they still have my engine at service. they told me they tore it down and replaced the bearings and it still dont run right. its going on 2 months and its still not done WTH

Then I would suggest a hot phone call to service on Monday morning. The number is 775-782-4562. Anytime after 9am west coast time.

Sorry for the headache.