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Hello, Recently replaced the intake valve seal on my so called 20HP Briggs single. Now it smokes more. Removed the head and tried to do it right. My guess is I tore the valve seal installing it with a 10mm deep socket. Any other ideas? If I give it to my daughter as is she will probably run it out of oil.....Jay

Are you sure it was the intake seal causing it to smoke.

No, not sure just a slightly educated guess............Jay

generally if you have a bad valve seal there will be quite a bit of carbon build up on the intake valve. What does it smoke like, is it real heavy on start up and then clears up a little, or is it constant in how much smoke it blows?
What does your oil level look like?

Did you look at the head gasket?
Put in a new one?

Thanks for the reply's. I did replace the head gasket. Before replacing valve seal and head gasket the oil was black, even though the oil and filter were recently changed. My guess was the head gasket was partially blown between the combustion chamber and the push rod area. It did look like it was kinda leaking there. There was a lot of carbon on the face of the intake valve but not much on the stem. Guess it could be rings bad as it has mowed an a 1 acre lot for over 12 years. The blue smoke shows when the engine speed is raised. Not much otherwise. The oil is below the add mark after mowing and no leaks so it is going somewhere..............Jay

How long have you ran it since the new gasket?

It has only run about 90 minutes since back together. It is just to HOT to mow in North Carolina!!!

Are you using the correct weight oil?

Scrubcadet10 said:

Are you using the correct weight oil?

Click to expand...

Is your oil level over full? Indicating gas in your oil.

Walt Conner

Using 30W oil and it is not over full. Run it for 1 and a half or two hours and it is down a 1/4 below the add mark............Jay

Take off the valve cover out in the yard, and start the engine for half of a minute and look at the pushrods/etc..
Look for compression escaping. The new gasket may be leaking already. Oil will fling about a bit, it will spray if there is a leak.
Don't run it long like this.

pull the breather tube off the back of the air filter housing.
If it pumps out a lot of oil then you have a ring / gasket problem.

Oil is not over full, just the opposite, it uses oil. Using straight 30W oil. It has always been good on oil except this last season. Usually down to the add mark after mowing for about 90 minutes but chained to 1/4 inch below add mark after 90 min mowing........Jay