[AT] Subject: Re: 16 HP Onan twin

[Greg Hass]

Over the years I have seen 4 of this problem although I'm not in the 
business. All were aluminum engines. A couple I tried the punching 
around the valve trick; both only lasted a few hours. The last was on my 
daughters mower. It was an overhead valve single cylinder. I called the 
repair place and asked what they did for this problem and they said a 
new head, which is what I did and it is still running. As has already 
been mentioned I know of no glue that would take the heat plus the 
hammering action of the valve. Also, because they were aluminum engines, 
the hole for the seat had been slopped out causing an even bigger problem.
                Greg Hass