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Author Topic: Valve Seat Ring Came out - Briggs 12.5 IC  (Read 598 times)

Offline cab50

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Valve Seat Ring Came out - Briggs 12.5 IC
« on: April 24, 2020, 04:08:05 PM »
Hi there

My engine was turning and not starting - did all the usual checks, electrical, fuel etc - notice low to nil compression. Took me a few days to get the exhaust bolts out to take the manifold off but got there with help from a friend (at a distance!).

Then we could see the ring for the carb valve had come out and was sat across the opening meaning it was blocking the valve open. Have put it back in the right place but not pushed it in just to see if the valves are all moving - and they are. Piston lining looks good.

My questions are - tips to re seat this - does it need a new one - what would stop it all just coming out again - any tips from people who have seen this before. Is there a company we can use to stick it in firmly - have seen online some people hammer the metal over it but am not inclined to do that as it seems a bit over the top?

Photos attached.

Thanks in advance Colin

Offline Mick

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Re: Valve Seat Ring Came out - Briggs 12.5 IC
« Reply #1 on: April 24, 2020, 04:52:59 PM »
Hi Colin, and welcome to TGMF.

It's a pretty common problem on these engines, especially if they have run excessively hot for some reason such as blocked cooling fins, flywheel screen, etc. 

The method you've seen where the metal is pushed back over the seat to hold it in is also common and something I've done on many an occasion without any further issues.   Done properly, It would entail removing the valve and lapping it in afterwards, and setting the tappet clearance.   

Other than that you'd have to take it into a engineering company to have the seat refitted or new one made and fitted.  A engine preconditioner would be a good place to seek advice if not waning to tackle it yourself.