Lawn Boy 10525 990series (1999-2000 manufactured) won't start

[zeebanker]

Gentlemen-
New to the forum. I'm helping an older neighbor with his Lawn Boy. He had it at his cabin, under a deck for over a year and this summer when he went to start it, it wouldn't. I said I'd help because I'm reasonably handy and have some experience servicing my own Toro 20037.

So after reading these forums and researching online, I learned that it has a Tecumseh 2-stroke engine. There was water in the gas tank, rust/water in the carb and the engine was seized (couldn't pull the start cord), blade is rusted and the thing is generally in bad shape. I took everything apart and this is what I did so far:

1. Cleaned out the carb, replaced the main jet
2. Emptied the gas tank, cleaned and dried it
3. Replaced the air filter
4. Replaced the fuel line and added an in-line fuel filter
5. Took apart the recoil shroud and mechanism, cleaned them both
6. Removed the blade and mulching blade - both are rusted and beyond repair
7. Removed the muffler, cleaned and replaced it
8. New spark plug
9. Sprayed non-silicone engine cleaner in the engine. Bore/piston didn't seem to be in a bad shape at all. Turns fine now.
10. Brake works fine (needed to lube the cable a bit).
11. Have left the self-propel mechanism alone for now. My goal is to get the engine running first.
12. Cleaned and replaced the primer line and put a new primer bulb in (old one was beginning to fray)

Put everything back together. Put clean gas and 2-stroke engine oil (50:1 ratio as seemed to be common). There's a spark (visible with plug outside). There's gas in the carb.

Pulled it. Nothing. Seems to pull ok, but I can't tell if there's enough pressure (I don't know how tight it should be, my Toro feels tighter).

What next? Appreciate any and all troubleshooting help.

 

[tom3]

I'd suspect bad reed valve or bad crank seals. Not sure that old mower is worth all that work, and might start getting into some serious money

 

[zeebanker]

Thanks Tom. I did notice some rust on the lower reed valve. I cleaned it best I could, but didn't actually take it out of the engine.

 

[zeebanker]

I'd suspect bad reed valve or bad crank seals. Not sure that old mower is worth all that work, and might start getting into some serious money

How would we test / eliminate those?

 

[intruder1500]

Maybe worth a try....take out the air filter and squirt some fuel straight into the carb throat....prime 3 times ….set choke ….and pull away! Worked for me when my 10525 was being stubborn.....until I cleaned the carb. Now back to one pull start.
PS - you will probably have some difficulty getting the mulching blade. I bought a junk mower just to get that.

 

[tom3]

Don't know if you can do this on that motor but, When my old LB won't start I get out the drill, chuck up an adapter and a socket that fits the flywheel bolt, spin away. Usually will start it up and teaches it a lesson. Make sure the motor brake is not on, cross bar on upper handle deal. When the motor starts keep the drill running while you pull it off.

 

[FuzzyDriver]

Tom3: I use a cordless drill to check compression (no sparkplug, so obviously not going to start). It seemed too dangerous to me to use this method to start the mower....but having said that, there is an adapter that they make to convert a breaker bar into a ratchet. So, if you DO use your electric drill to start it, then it could take off and whiz the ratchet rather than tearing the drill out of your hand. Any thoughts on that?

 

[tom3]

That sounds like a pretty neat tool actually. Never had a problem with the drill going wild but have had the socket stay with the motor and had to shut it down to get it off. We live dangerously here in Appalachia.

 

[1saxman]

BTW, its not a Tecumseh engine if its a 2-cycle. Lawn-Boy was using Tecumseh 4-cycle engines on models like the 10684. Your Dura-Force 'E' engine was the last 2-cycle made by Toro/Lawn-Boy.