18 hp vanguard bending pushrods

[digger2]

HEY GUYS,
My mother has a White garden tractor with a 18 hp Vanguard
twin engine on it.I think its a 1994 model.My dad bought it new and always
maintained it,but now since he's gone its my baby to fix it when it breaks.
It quit running last fall while she was mowing grass and i'm just getting around to looking at it.I brought it home and started looking for the problem and found a bent pushrod.Not slightly bent,but REALLY bent.I checked for any binding in the valvetrain and it seems to work freely,and i dont think theres anything in the cylinder floating around to cause any interference with the valve.And seeing as it is governed,i dont think it was over revved.
My only idea is maybe she was running it too slow while mowing grass
(she is almost 80) and the engine heated up enough to seize the valve and
causing the bent pushrod problem,and when it cooled down,the valve freed-
up.Like i said,i cant find anything wrong now.
I know these are supposed to be good engines and really,its the first problem its had,but has anybody else had this problem?
Digger2

 

[atschirner]

You're on the right track with the sticking valve. My buddy repaired his neighbor's mower last year. He also had bent push rods on a Vanguard that turned into a stuck valve. The least hassle and lowest cost option is likely purchasing a replacement head with valves. There is a Briggs 809200 head on eBay right now for $105. Other suppliers are in the $160 to $200 range for this part number.

 

[digger2]

Thanks for the reply guy,i'll check it out
digger2