inMower will not start

[Tiger Small Engine]

Did you try it plugs in and plugs out ?
If it is slow both ways then either the engine has a partial seizure or the starter is kaput
If you can put your palm on the debris screen on the debris screen & rotate the engine then the only thing left is the starter .

Working on a Briggs 31P677 right now with starter problem. Customer replaced starter with one that has 14 teeth on gear, and needs one that has 16 teeth, so gear keeps hanging in flywheel. Odd thing is it turns over fine with no spark plug, but turns a quarter turn with spark plug in and stops. Valves just adjusted. It’s always something…

 

[Lui_5793]

Just with plug in. After work today I will try with plug out.
Engine did turn over but when it was as compression stroke, the starter would not be able to turn the engine. I had to turn the engine manually to get it out of compression stroke and once I jumped the starter again, it would turn over. Once at compression stroke and jumping starter, you can hear it engage but it would barely move the flywheel. I would keep touch ground and it would just nudge the flywheel.

 

[bertsmobile1]

That really sounds like a decompression problem
Forcing starters to turn over engines they can not will burn out the starter motor
When the individual windings are powered, they are a direct short .
There is nothing between the + & - but a few yards of wire so when the starter stalls a lot of amps flow through that short which generates a lot of heat which does a lot of damage

 

[Lui_5793]

That really sounds like a decompression problem
Forcing starters to turn over engines they can not will burn out the starter motor
When the individual windings are powered, they are a direct short .
There is nothing between the + & - but a few yards of wire so when the starter stalls a lot of amps flow through that short which generates a lot of heat which does a lot of damage

So what do you think the issue could be ? New starter ?

 

[Lui_5793]

So what do you think the issue could be ? New starter ?

I haven’t been able to test the mower with plug out today cause of rain and have no cover to do the tests.

 

[Tiger Small Engine]

I haven’t been able to test the mower with plug out today cause of rain and have no cover to do the tests.

What Bertsmobile is trying to say, is internally on the cam, the compression release mechanism may be broken. If that is the case, it requires removing engine and opening it up to replace part. You need to remove valve cover and watch very closely for “bump” on valve. Sometimes it is on exhaust and sometimes on intake. If you need more details, let us know.

 

[Lui_5793]

I got a chance to test mower with both plug in and out of mower. In mower, it can’t get passed the compression stroke unless I physically move it out of that stroke, then it has no issue turning over aside from turning over slowly and once you let the ground jumper off ground and back on, starter doesn’t do anything but try to engage. Once plug is out, it turns over without any issue but starter sounds rough either way and spins somewhat faster but not by much. And before we jump to the ACR, I already have taken the engine apart and found that it was still intact and the valves do jump which mean it is working. Trust me, when I first saw the symptom of the engine turning over and stopping at the compression stroke, that was my go to. I also had a tech at a shop I work at look at the cam and he says it looks fine and the compression release mechanism doesn’t seem to be seized up by any means. He also referenced to the bump in the valves which I never knew about until he told me. With plug in, I held the ground jumper longer on a bolt on the frame just to see if it would eventually get past compression but starter never budged.