Sounds like blown head gasket. They always blow between the cylinder and the push rod gallery so no outside indication.

Walt Conner

Hey thanks Walt! I am hoping it's head gasket versus piston/rings. I will order the head gasket. Unfortunately, I have another issue to fix first. When I was taking off the flywheel to take a look at the oil breather reed valve, I used a backyard method to pulling the flywheel (instead of using a puller). Well I ended up stripping the last 3 threads on the flywheel bolt, which is no problem becauase getting another bolt is cheap.

The problem is that I slightly damaged the 1st 3 threads into the crank. Do you have any suggestions as to what to do at this point? (other than buy a new crank $167 from Briggs). I was thinking about possibly using oil and a new bolt to see if it will turn in. I can still see threads in the crank but the 1st three look a little damaged but I can still see their grooves. The bolt, however, was totally destroyed at the last three threads (no grooves). I'm thinking that the bolt is softer and will strip before the threads in the crank to prevent idiots like me from stripping out the threads in crank, when they are too impatient to wait until the next day to buy or borrow a puller!

Get yourself the correct tap and chase the holes using plenty of oil and patience. That is right way. I have had a fair degree of success just using a good bolt or 2. Once or twice, I have even filed flutes into a bolt too.

"The problem is that I slightly damaged the 1st 3 threads into the crank. Do you have any suggestions as to what to do at this point? "

Barrow a tap from Auto Parts Store or a friend. I am lucky enough to have a friend who has every tool you can think of.

Walt Conner

Thanks Andyma and Walt for your replies! I decided to put the flywheel back on, then use the old damaged flywheel bolt and just hammer on it as hard as possible into the tapered end of the crank. Then I used some epoxy so it doesn't back out. Haha! Just kidding! Actually I ordered a new flywheel bolt yesterday. When it comes in, I will try to see if it turns in using absolutely no force. If it doesn't then I will use tap. I'm glad to know there is hope!

UPDATE:

My brother has a tap & die set, but it only went up to 1/2 inch. So, we measured the flywheel bolt threads and diameter. I bought a 9/16" 18 TPI tap from local hardware store. I put lots of oil on tap and crankshaft threads. Then turned into crank with adjustable wrench. After about 3 turns, the tap turned very easy so I decided to clean the rest of the threads. Then I turned in the new flywheel bolt and torqued to 100 ft lbs. Mower started right up! Now I will order head gasket and see it if stops the smoking.

UPDATE:

My brother has a tap & die set, but it only went up to 1/2 inch. So, we measured the flywheel bolt threads and diameter. I bought a 9/16" 18 TPI tap from local hardware store. I put lots of oil on tap and crankshaft threads. Then turned into crank with adjustable wrench. After about 3 turns, the tap turned very easy so I decided to clean the rest of the threads. Then I turned in the new flywheel bolt and torqued to 100 ft lbs. Mower started right up! Now I will order head gasket and see it if stops the smoking.