Tecumseh LV195SE lawn mower engine won't start.

[Dave T S]

You will likely still see the original cross hatch in the engine and they probably won't be any scores at all but if you see a few vertical ones as long as there's not five or six around the bore and as long as they're just fairly small and you can't really catch your fingernail in them too much it's not really a concern.
For that base gasket or some gasket or what do they call it, they usually don't leak a lot there but I have found tricks to fix them.

I had several of the Kohler XT engines come in that were leaking down there.
You tilt The Mower and whichever side or angle you need to so there's no more oil puddling on the inside there and then blast it with carb cleaner three or four times and with compressed air to get all the oil off the area... Then you can take some of the good RTV like the ultra stuff that's more oil resistant and spirit and push it right into the gasket area.
Some of these are so hidden that I had to use it on the tip of a screwdriver but as long as you push it in there with a wiping motion and then I usually go back and dab some more on top but still pushing it on top and then leveling it out to the sides.

I think I've done three of the colors so far maybe four and not have one of them leaked afterwards

I left them up in the air like that to dry overnight and then set them back down and started them.
If it works it works.

Thank you.

 

[Dave T S]

Scoring on the piston, rings, and cylinder on a four stroke:
Being able to tell if the compression is too low due to excessive scoring takes experience. There is no set “go, no go level.” You can only see the condition of cylinder, without removing the head and taking the piston off of the connecting rod. Therefore it is the cylinder you are focusing on. Need an endoscope to see into the spark plug hole. Therefore without the proper tools and experience, it is difficult to look for scoring.

I have the engine block and base separated. I'm going to clean internally and look at the bore, piston, etc. If I can catch a fingernail on vertical internal bore marks is there any hope? Do I disconnect the connecting rod, piston and review the rings and how they appear? Not sure how far to really take the bore score marks and rings. Thanks.

 

[Rivets]

You are way over thinking this. Don’t even need to remove the engine from the equipment. To check for scoring all you need to do is remove the head and look at the cylinder. A good mechanic can quickly ( in 15 seconds ) identify a cylinder which has been damaged. You only need to be able to see the top 1/3 of the cylinder. Have you even looked at the manual I posted?

 

[VegetiveSteam]

About the compression, you have to remember that engine has a compression release so you're never going to see 90 to 120 lbs of compression. If you did it would probably rip the starter rope out of your hand when you pulled it. Tecumseh always stated that an engine with a compression release should never have compression over 90 lbs. They said if it's over 90 lbs, you likely have bad compression release. For engines with a compression release, a cylinder leak down test is the better way to test the integrity of the cylinder and related components.

 

[slomo]

Have you removed the spark plug and replaced it with a new one

Heck ya', first troubleshooting thing on the list for all mowers. The ol' spark plug trick.

 

[slomo]

You are way over thinking this. Don’t even need to remove the engine from the equipment. To check for scoring all you need to do is remove the head and look at the cylinder. A good mechanic can quickly ( in 15 seconds ) identify a cylinder which has been damaged. You only need to be able to see the top 1/3 of the cylinder. Have you even looked at the manual I posted?

Or use a cheap USB bore scope. Tug on the rope to lower the piston in the bore. Some you might not see the bore maybe. Still cheap to pull the head. Probably needs de-carboning of the cylinder/s anyway.

 

[Rivets]

A bore scope??? Why? The price of a head gasket is far cheaper and will give you more info than a bore scope. The OP doesn’t even know what he’s looking for.

 

[VRR.DYNDNS>BIZ]

Thank you. Key is intact. I'd taken a compression measurement and it is at approximately 45 psi. I read that it should be between 90 and 120 psi.

That level of compression will make things very very difficult to get it to start. the speed of piston moment makes a difference in firinng time compression. In our shop, we do a slow pull and feel the compression. If little resistance, no need to go farther. It's dead.

 

[slomo]

A bore scope??? Why? The price of a head gasket is far cheaper and will give you more info than a bore scope. The OP doesn’t even know what he’s looking for.

Why not? More tools the better. If you don't like tools then more for me.

I did agree with you by saying "Still cheap to pull the head. Probably needs de-carboning of the cylinder/s anyway."

 

[Dave T S]

You are way over thinking this. Don’t even need to remove the engine from the equipment. To check for scoring all you need to do is remove the head and look at the cylinder. A good mechanic can quickly ( in 15 seconds ) identify a cylinder which has been damaged. You only need to be able to see the top 1/3 of the cylinder. Have you even looked at the manual I posted?

Thanks, however, the reason I did what I did was because the base flange gasket leaked oil pretty badly. Also, I wanted to learn something as I've never done this before.