deere mower has hard tme cranking

[John Groleau]

Hello, I have a ten year old john deere 145 automatic lawn tractor which has work well until recently. The problem is starting, It kills batteries. If I jump start with my tundra truck, it will spin for a while then stop on the compression stroke. I seem to have excessive compression an won't spin. I've talked to the deere people. They advise me to adjust the valves to .004 when the rockers are no being in use. They also said to find top dead center, let the piston go back down one quarter of an inch, the set the valves to .004.
I have done this and doesn't seem to help. It is possible that the decompression mechanism on the cam shaft is broken? Could the starter be weak? The jumper cables are quite warm after cranking.
Runs good once I can get it started. Any thoughts, thanks, John

 

[beenthere]

:welcome: to TBN
You may need to inspect the compression release for a problem.
Had a B&S engine apart due to too much compression problem that apparently happened when the previous owner over-filled the crankcase with oil. Bent the small delicate spring that holds the cam for compression release, and let's go when started firing.

Subtle problem and hard to find without tearing the engine down.

 

[John Groleau]

Thanks beenthere, I think you are right, engine teardown sounds awful, but you hit the nail on the head.