Hello; A day that seems to have turned out better than I had hoped. I have two very old push lawn mowers. Both the same with Briggs Quantum engines. The old style with big rear wheels and an actual throttle. May be around 20 years old. I was thinking one of the mowers had reached it's end. Been down on power all summer and finally just would not run. I had tried al the normal stuff I do to keep them running.
So I took the engine down further than ever before. Found two things. One being the head bolts had loosened up some and it was losing some compression. That likely was why it was down on power. It also allowed some blow-by onto one of the head bolts which built up some carbon and corrosion on the threads. That head bolt broke off leaving an inch or so in the cylinder.
The other thing was that the intake valve seat had worked lose and was no longer seated. The valve was blocked open so it had no compression at all. Thought all was lost for a bit. After a good look I determined no real damage. So I decided to try to fix it.
I drilled out the broken head bolt without ruining the block. Took some time but I did OK. Been a while since I have done that.
I seated the valve guide by peening all around it with a hammer and a pointed punch. That moves the softer block metal. I hope it made it tight enough to hold.
Anyway I put it back together today and the darn thing started up and ran. Do not have any notion if it will last. I should have at least one more mow this season and may find out.
So for the rest of the day I plan to watch the replay of the TN vs. Auburn which is on right now. I think TN won which I did not expect.
After that I will watch the two hour Power Nation TV shows I recorded this morning. Pretty good shows if you like working on car. Katie Osborne who introduces the shows also does a good job.
Not bad for a dreary rainy and cool day. The rumors I think are true in that winter is coming.
So I took the engine down further than ever before. Found two things. One being the head bolts had loosened up some and it was losing some compression. That likely was why it was down on power. It also allowed some blow-by onto one of the head bolts which built up some carbon and corrosion on the threads. That head bolt broke off leaving an inch or so in the cylinder.
The other thing was that the intake valve seat had worked lose and was no longer seated. The valve was blocked open so it had no compression at all. Thought all was lost for a bit. After a good look I determined no real damage. So I decided to try to fix it.
I drilled out the broken head bolt without ruining the block. Took some time but I did OK. Been a while since I have done that.
I seated the valve guide by peening all around it with a hammer and a pointed punch. That moves the softer block metal. I hope it made it tight enough to hold.
Anyway I put it back together today and the darn thing started up and ran. Do not have any notion if it will last. I should have at least one more mow this season and may find out.
So for the rest of the day I plan to watch the replay of the TN vs. Auburn which is on right now. I think TN won which I did not expect.
After that I will watch the two hour Power Nation TV shows I recorded this morning. Pretty good shows if you like working on car. Katie Osborne who introduces the shows also does a good job.
Not bad for a dreary rainy and cool day. The rumors I think are true in that winter is coming.