Onan 20 hp P220G intake valve seat issue

[davidtmercer 46]

Looking for advice for those who have been there done that.

I have a low hour 20 hp Onan from a 1996 520-H that has the classic loose intake seat issue on cylinder 2 (right side when looking at the flywheel side of the crankshaft).

Upon further review, either the previous owner or the Onan factory installed a .130" oversized intake valve seat (1.572" outside diameter, .515" thick)

I am not aware of an oversized valve seat commercially available larger than .120" (Onanparts.com) so the only option I am pursuing is purchasing a stripped down standard bore block on e-bay and using the parts from my Onan engine to get the 520-H back into service.

Any advice on what you would recommend I do or if you have a standard bore block available for sale would be appreciated. 

[RED-Z06 2,120]

26 minutes ago, davidtmercer said:

Looking for advice for those who have been there done that.

I have a low hour 20 hp Onan from a 1996 520-H that has the classic loose intake seat issue on cylinder 2 (right side when looking at the flywheel side of the crankshaft).

Upon further review, either the previous owner or the Onan factory installed a .130" oversized intake valve seat (1.572" outside diameter, .515" thick)

I am not aware of an oversized valve seat commercially available larger than .120" (Onanparts.com) so the only option I am pursuing is purchasing a stripped down standard bore block on e-bay and using the parts from my Onan engine to get the 520-H back into service.

Any advice on what you would recommend I do or if you have a standard bore block available for sale would be appreciated. 

A machinist could tig weld the bore and counter bore it to a new seat.  It could take some time to find another P220 with the WH Pto that fits the clutch, that isn't also suffering from seat failure.  My Deere 420 ate a seat at 700hrs and it took 9 months to find an engine and i still had to have the cracked starter mounts welded up and replace the governor spacer