YS 61 ST1 Update
 

Hi again

I posted about a YS 61 ST 1 with very low run time that quit often in FFF. I was advised to run 30% fuel in it so I went ahead and picked some up and decided to bench run to test the engine.
I ran it with the 30% and used a 12 x 6 for loading. It appears that the starting needle positions are still lean. I doubt the manual is incorrect and the engine seems clean but I did not take the regulator apart. It ended up running at 1 3/4 hover needle to allow for a transition without stalling and it appears the hover needle also called the main affects the sub needle or the high end? To get the high end rich to the point of hearing a RPM increase with the line pinched required 3 turns out. At the original 2 turns it would quit at full throttle.

The manual calls for 2 turns on the sub or high needle and 1.5 on the main or hover. Is it okay to go ahead and mount and work back form here or should I be looking for a problem causing the odd needle positions and where would I look if needed?

Mat

RE: YS 61 ST1 Update
 

Sounds like a regulator problem, but hard to say exactly. The ST1's could be troublesome. Why not upgrade to a new ST2? Call me at 775-265-7523 and we can discuss it if you're interested.

Dave