Popping sound
- Thread starter slow030
- Start date
sgkent
Lawn Addict
Briggs made both overhead valve and L-head 190 cc engines.
I used to build automotive heads for a living. The answer to your question is an unknown. Sometimes the peening will hold a slightly loose seat depending on how much crush you can get on it with a peen, and how much aluminum you have to work with to hold it in. It is not the preferred method but a mower engine is too inexpensive to go thru the process unless you own the machine shop or your brother does, etc.. However the seat has already fallen out, which sort of implies two things, (1) the seat is really loose, and (2) that the engine got really hot at one time (which has to be dealt with if it is still happening). The danger of a loose seat is it drops again, the valve bends, which destroy the guide and the valve. The valve head then rattles around the combustion chamber and destroys the piston and cylinder walls.
Is this an overhead valve engine 190cc , or 190cc engine where the valves are in the block? If it is overhead, buy a new head now before the seat comes loose again and destroys the engine.
I used to build automotive heads for a living. The answer to your question is an unknown. Sometimes the peening will hold a slightly loose seat depending on how much crush you can get on it with a peen, and how much aluminum you have to work with to hold it in. It is not the preferred method but a mower engine is too inexpensive to go thru the process unless you own the machine shop or your brother does, etc.. However the seat has already fallen out, which sort of implies two things, (1) the seat is really loose, and (2) that the engine got really hot at one time (which has to be dealt with if it is still happening). The danger of a loose seat is it drops again, the valve bends, which destroy the guide and the valve. The valve head then rattles around the combustion chamber and destroys the piston and cylinder walls.
Is this an overhead valve engine 190cc , or 190cc engine where the valves are in the block? If it is overhead, buy a new head now before the seat comes loose again and destroys the engine.
Let me guess, a bulb type spark tester.
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Need to smack some aluminum material over the valve seat to hold it in. Kind of stake it in there.....
Need to ask WHY the valve seat popped out?
Ever clean the cooling fins? Ever?
Great time to de-carbon the cylinder too. Do a valve job and set the valve clearance. Lap the head and block where the head sits while you are there.
sgkent
Lawn Addict
it isn't the best solution but with an L-head engine you replace the crankcase or whole engine when that happens. It is too expensive to tig it, then cut it for new valve seats. This is from another forum but it is how one would do it. It is a temporary fix, it will eventually fail again when the peens fracture but it should last a while. Gravity is on your side with an L-Head engine. Make sure the cooling system is optimal - no junk on the fins or fan etc..
ILENGINE
Lawn Royalty
I have several done engines like this over the years and have never had a repeat failure. Even have done a few on the Briggs intek heads. Actually just did one a couple weeks ago.it isn't the best solution but with an L-head engine you replace the crankcase or whole engine when that happens. It is too expensive to tig it, then cut it for new valve seats. This is from another forum but it is how one would do it. It is a temporary fix, it will eventually fail again when the peens fracture but it should last a while. Gravity is on your side with an L-Head engine. Make sure the cooling system is optimal - no junk on the fins or fan etc..
Tiger Small Engine
Lawn Addict
I have peened the valve seats on a couple of different engines and never had a comeback. If done correctly I believe it works long term. Briggs even lists it as a legitimate repair in service manual.
Auto Doc's
Lawn Addict
It appears a little resistance on the pull cord means it has "compression" to some folks.
If a valve seat popped out, that is usually a sign of plugged up cooling fins and running low on oil for too long.
The valve seat can be re-installed and then a center punch is used in several spots around the seat area to "peen" the aluminum tightly to hold the valve seat. Often this method works but be aware that the problem my happen again.
A long-time repair would be to purchase a new/used head to replace it with.
If a valve seat popped out, that is usually a sign of plugged up cooling fins and running low on oil for too long.
The valve seat can be re-installed and then a center punch is used in several spots around the seat area to "peen" the aluminum tightly to hold the valve seat. Often this method works but be aware that the problem my happen again.
A long-time repair would be to purchase a new/used head to replace it with.
ILENGINE
Lawn Royalty
Have you also found that most of the time the seat that comes out/loose is the intake valve seat.