Did the pump wear problems ever get fixed?
Some guys were putting inserts into the valve face.....the pump piston was wearing out quickly too.....this was on the fuel pumps...the rest of the engine was great.
This was on the 170 and later versions.
I have 25 cases of CP 30% that I need to use but I had so much trouble that I had perhaps 8 flights over 2 years...I had to give up using these engines until more development had taken place.
The most experienced YS tuners (not me!) had worked on it and given advice...I have a nice airplane and everything else just rotting away for almost 4 years now.
Has the pump been fixed??

Dave
NSRCA 586
AMA 5053