Unusual battery issue

[donb108]

Try jumping the battery positive directly to the starter red terminal. If it always turns well, it may be the solinoid or bad connection somewhere.

I finally got access to this mower. Using a jumper cable, I went directly from the battery to the starter; it slowly turned. We tried again and got varying results (a little faster and then a little slower), but none were good enough.

If it still struggles, try will no spark plug. should always trun fast.

Unfortunately, I didn't have any tools with me, so couldn't do this one.

I have seen very many starters that are tight due to bad internal bearings or just worn out. If you lower the starter from the flywheel, you should be able to turn, not only the bendix gear, but the whole motor easily.

I'm tempted to just throw on a replacement starter, but maybe not. I'll go back over and try the next couple of things.

 

[Cusser]

Don't "just" throw a new starter on, try with the spark plug out.

 

[donb108]

We did the tests last night, here's what happened.

Removed spark plug - Engine cranked over very well. It turned fairly fast and looked like normal turning. Repeated several times and it did the same thing each time; nothing looked unusual.

Tested spark plug - It's an old plug and wet with gas from all my testing, but has a good spark.

Removed starter and turned by hand - The gear moves freely and the motor shaft moves freely. I could feel the coils moving past the magnets, but nothing felt like it was binding. At the end of all the testing, the motor was very hot, almost untouchable; maybe that's normal. During several of the next cranking tests, the gear got stuck in the up position, but came back after I manually turned the flywheel.

I replaced the spark plug, cranked it a bunch of times, here's what it looked like:
- On some tries, it would not turn at all, just click once. Then I tried again and nothing would happen and no click. I turned the flywheel a little, tried again, and then it cranked, but very slowly.
- On some tries, it started turning very slowly at first and then it moved faster as it cranked.
- Several times, the gear got stuck in the up position, engaged with the flywheel gear.
- On most attempts, it would start turning slowly and then move a little faster, but not much faster. Lots of tries were like this.
- On most tries that lasted more than a few seconds, it slowed down as if the battery was dying.
- If I turned the flywheel by hand to find an unloaded spot and then tried it, it seemed to crank a little better.

By the way, when I started working on this mower, everything was covered with grass, grease, other junk. I sprayed a bunch of stuff down with brake cleaner, including the starter gear and part of the flywheel. Maybe I should re-grease some parts.

Looking at valve adjustment videos, it seems like that's the next thing to try. I haven't found the exact spec on this engine, but .004 - .006 for intake and .006 - .008 for exhaust seems to be the general range. Does anyone know the exact spec, or is this close enough?