I think I see the bump

[PTmowerMech]

But after checking the push rods, which were straight, adjusting the valves (.005/.005), and jumping with a good battery it's still acting like the compression release is bad. The view is from the camera laying under the head facing up. Turns til the compression stroke then barely moves passed it.

BTW, I also jumped straight to the starter.

 

[ILENGINE]

After watching several times I don;t think it is decompressing correctly. Hard to tell with the uneven turning which kind of give a false feel of it being there. Where the bump off should be just don't look right.

 

[PTmowerMech]

After watching several times I don;t think it is decompressing correctly. Hard to tell with the uneven turning which kind of give a false feel of it being there. Where the bump off should be just don't look right.

Sometimes it would bump, sometimes not. I'm thinking the times it did, was after letting go, the flywheel would stop and turn back just a hair. Making it look like a bump.
I put a fully charged batter on it, a new one in fact, and it still stops, then eases over the compression stroke. I rechecked the valves, and they're still set at .005 each.

When I get back out there, I may put the big drill, with a socket to it and rerecord the video. Because some rotations looked like it was bumping. And some didn't. Seems they all would've bumped.

 

[Luffydog]

I never saw the bump. Make sure that it's tdc and on the compression stroke set at .004 and retry.

 

[Luffydog]

I would also check to see if there was gas in the oil to rule that out as well

 

[Tinkerer200]

Spring on Compression Release may have broken or come off giving those intermittent results.
Walt Conner

 

[TylerFrankel1]

It does seem pretty iffy as to if it's bumping or not. Before you tear it apart make sure the connection is tight at the starter. Take off the positive battery lead from the starter, then tighten down the nut that is left on the standoff. Then reattach and tighten the battery lead to the starter. If that doesn't work, and you have a bit of time on your hands (and 10 bucks for a new sump cover gasket) I'd tear it down and check the compression release on the cam. See if it's sticky or damaged.

 

[ILENGINE]

If I was the OP and opened the engine us to check the compression release I would have a new cam ready to drop in. Seen too many of them with somewhat iffy operation over the years, and for the time it takes to get to the cam it isn't work the effort to have to do it a second time.

 

[PTmowerMech]

Starter & battery connection's cleaned. Valves adjusted to .005 (which is fine) nothing but oil in the oil.


The spring is to keep the CR closed on low rpms, correct?

Customer can't afford the repair. Says they'll just put a stronger battery on it. Even after explaining about the broken CR fragments probably still lying inside the engine. And the damage they could do.

Repair on the cam. Plus a ton of other stuff. Drive and deck idlers, spindle bearings.

 

[TylerFrankel1]

The customer is making a mistake, not uncommon. A bigger battery isn't gonna solve the busted metal or likelihood of it getting worse.

Spring holds the compression release so that it bumps the valves until centrifugal force overpowers the spring at high RPMs and flattens the compression release hump. Taryl does a good job explaining this at 8:24 of this video: