Briggs 12.5HP engine problems

[SmallTimeMowerGuy]

Noted, I'll keep that in my records for the next(if ever) time I do it. I have to fabricate a spring compressor so I don't buy yet another tool for a 1x build. I thought I had it done but the one I built didn't' work on the exhaust valve spring. with that I'll pull it apart again and reset the clearance to max rather then min settings, I wasn't sure which to do so went with the minimum, but after thinking it does make sense that the gap closes over time to to simple wear on the stem.

More to follow once I get it all back together.....

 

[SmallTimeMowerGuy]

Can anyone confirm if on 286707-0441-01 12.5hp Briggs engine has a compression relief built into the Crank/valves? Ie does the crank keep one of the valves open slightly to bleed off the compression to allow the engine to rotate to start? when I rotate the engine clockwise by hand, there is a point where both valves are slightly open(ie about 1/10 the way).....normal?

 

[slomo]

Not confirmed but a 12.5hp engine would either pull the rope out of your shoulder or stall a starter easily. Thinking it must have one. The more intelligent guys on here can verify your question. We have a great team of people on here.

slomo

 

[SmallTimeMowerGuy]

So just a random update on this.
Everything is all back together and still the problem persisted....
So I started looking deeper.

I found one problem was the main drive belt is way too tight, and it binds on 2 of the "keepers" and just doesn't allow the machine to turn over. I loosened the belt off a bit and it started to turn over better for sure.

Curios thing now....it seems as if fuel is spitting out of the carb intske side.

Still no start but some headway.

Hoping the large issues are compete now and on to a dirty carb or something similar.

Will need a longer belt for sure as the one I have is way too tight it seems.

 

[SmallTimeMowerGuy]

I should also mention that i think the starter is dead, it still turns over the starter on the key, however the stsrter does not engage the flywheel to turn the engine over.

This has been quite the project, never again will i attempt this type of mower repair....lol

 

[Rivets]

If the starter spins over, but does not push the bendix gear up, you either have a weak battery or a bad bendix drive.

 

[SmallTimeMowerGuy]

So I took the starter off and apart.....I found that 1x bush was disconnected, and another wire came apart from the brush when I touched it. these were on the "neg" end of the starter. Tried bench testing both before and after I thought I fixed it and nothing, no spinny spin. I'm hoping that my Epoxy fix works after taking it apart again. I did have some smoke exit the starter when it was turning over and feel it's not getting enough juice not to turn it over. It is entirely possible the battery is on it's way out, however I hooked my car up to the battery via jumper cables and it didn't do anything different.

Chasing gremlins on this amazing learning experience. haha

 

[SmallTimeMowerGuy]

Main issue that I found with the "slow" turning of the engine was the belt I bought was too short. I believe the replacement for this tractor was a 82 2/3" belt when the original belt was a 84 1/3" belt or something in that range. Some people think size doesn't matter but it definitely does with a belt like this. The part number from Husqvarna's website matched up and I bought the belt locally(months ago) not realizing that somewhere along the lines the original P/N was superseded by an updated shorter belt. Original one for the tractor was loose feeling, new one was terrible to get on and in place and was SUPER tight. Now I'll have to figure out the proper length to run and change the belt.

Who knew that working on old Tractors would be more interesting and complicate then my old car?

 

[dougand3]

I'd leave the belts off until I got the engine running smoothly. No point in putting a load on at this time.

 

[SmallTimeMowerGuy]

The plan is to leave the drive belt off until it runs well.