Lawn Boy 2 Cycle Engine Seized

[Manjo]

I was fixing a grounding problem on the LB and I accidentally disconnected the automatic oil feed line. I reconnected the line and ran the engine for about an hour. Then the engine started to make strange noises and suddenly stopped. I tried to re-start the engine, but I could not turn the engine with the pull starter.

About an hour later, I tried the pull starter and I could turn the engine, but it would not start.

I have not had a chance to check anything, but I'm afraid I seized the engine either because the oil line came loose, or the automatic oil-to- gas system failed.

If the engine seized, what will I have to replace/repair? The engine is one of the last 2-cycle Lawn Boy manufactured themselves. Right now I think I would need a new piston and piston rings. Will the cylinder have to be honed or rebored?

Thanks in advance for your help, tips, suggestion, comments.

Manjo, Lawn Boy self-propelled with auto starter and auto fuel mix (oil automatically added to fuel)

[pheeh.zero]

What model is this? I have worked on electic-start LBs, self-propelled, and 4-cycle ones...wasn't aware of an oil-injected model!?

[dpb]

Manjo wrote: ...

...

All of the above at a minimum -- if it's Al block, there may not be enough lining material to rebore cylinders. Bearings and shaft probably as well. In all, if it actually ran w/o lube, new engine is probably cheaper than parts will be and the rebuild is a question anyway depending on how badly scored it is and whether warped head as well.

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[Manjo]

It's a 1991? model M21EMRD. I'm away from my manuals (by several hundred miles), but the LB online service manual is ibwpmm.pdf. It's been a great mower. Started easily and ran well until the engine kill mechanism failed and I got in there and accidentally screwed the auto oil injection system.

Until 1994, I had been using a 2-cycle push Lawnboy for 18 years. When it died, I naturally went with another LB 2-cycle.

If the parts costs get too great and I can't find a decent replacement engine, I'll reluctantly go to a self-propelled 4-cycle lawn mower.

Manjo

[Husky]

[Manjo]

Husky,

I've been away and on the road for the last 6 weeks and I'm only starting to look into the problem. I'm finding what you're saying to be true. There are a couple of web sites (non-LB) that have the crankshaft and some gaskets ($245) and other parts (many $'s). I'm going to tear down the mower this week and try to assess the damage and required parts. If I get lucky, I might find a similar used parts- engine. Otherwise, I'll be looking around the stores for a 4-cycle repalcement. Home Depot already has clearance sales on riding mower and I suspect there will be other good deals as the summer winds down and turns into Fall.

Thanks, Manjo

[trader4]

Geez, a 17 year old 2 cycle lawnmower with a seized engine? And you have to ask here what to do with it? Put it into the scrap heap.

[ransley]

245 for parts, for 275 I just got a 6.75 hp Toro with adjustable drive speed. Since when did lawnboys have a seperate oil system, i dont think they ever did.

[Manjo]

e quoted text -

Being a CYB (Cheap Yankee Bastard) and always interested in tinkering a bit, I'd like to keep the old girl running if I can. My previous LB ran for 14 years and ended up on the trash heep. It was still running like a top (with a wobble heare and there) and cut the grass. But what you write is probably true.

Manjo

[Manjo]

LB Model M21EMRD circa 1991. I think it was the last series of LB manufactured engines. Freshlube Oil Injection system mixed 2-cycle oil with gas. I have no idea how it did it, but it did it well for 17 years.

$275 is probably a bargain for a new mower and I will look into a new mower soon.

Thanks,

Manjo