Briggs & Stratton valve seats

weeb51

New member
I pulled the heads off of my Briggs 16hp engine and found one of the exhaust valve seats hanging up the valve. Does any one know what I need to do to secure this seat? Do I need to replace them and what kind of tools are needed to secure the seat?
 

Doc

Admin
Staff member
Gold Site Supporter
specialty tools are needed, Probably be best to take em to a machine shop. They shouldn't charge to much for that. Then you just have to reinstall it all.
 

Mith

Active member
If you place the valve seat back where it is supposed to sit you can use a center punch and lightly put dots in the metal around the seat. This will keep it in place.
 

Doc

Admin
Staff member
Gold Site Supporter
Good link Dean! You had me going for a minute there. I read the link as: fags .....thought you were pulling a quick one. :pat:
I should've known better cause I've never seen you do anything remotely like that. :pat: :pat:
 

Mark777

Member
I have done exactly what Mith has suggested. I did punch-dimple the head and (very carefully) the seat and should tell you the seat materials are very hard and somewhat brittle. So, do so carefully or the seat can break. I found by putting the seat between two soft blocks of wood (in a vice) helped to eliminate breaking or deforming.

After carefully heating the area with a propane torch, and no more than 250-300° - I fished out the seat that spent the night in my freezer. I was also fortunate to have an old exhaust valve that fit perfectly in the valve guide. Putting the seat in the head cut area, and using the old valve as a insertion tool, I tapped gently and drove the seat into place.

Although the process seemed perfect, fit snuggly and the geometry looked precise It was, perhaps, .002 out of concentric. Which meant a few hours of coarse lapping (with the discarded valve) and fine lapping with the original valve. IMHO…you get one shot at trying this and if it doesn’t go smoothly or fit perfectly, I would surrender the job to a machine shop.

I still have the engine and it runs fine (a Tecumseh 10 HP industrial).
 
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