Lawnboy piston help

Mobil, Yamaha and others have synthetic, and yes synthetic is better than Lawn boy oil , my Evenrude lets me use a leaner mix with synthetic as do many manufactures state this. Lawn boy just isnt on the bandwagon yet, synthetics have proven less wear, with an aluminum cilinder this is important.

im not blowin smoke, i been engine machinist since 1973. it is aluminum jug with cast iron cylinder liner. ive rerung and rebored many. parts arent much,just your time maybe,or lack of skill.

Too bad Lawn Boy uses a cast iron cylinder! I am not going to argue if synthetics are better or not, all I know is a properly maintained engine running regular oil will run for years. I am not sure it is worth the extra expense. Lawn Boy's oil is a good dino oil. Good enough that the mower will run until the rest of it falls apart first. Greg

If you have re-bored & re-rung many Lawn Boy's, where do you get the piston and rings? Lawn Boy does not offer them! Not for Lawn Boy's own two cycle engine anyway. Newer ones that come with a Briggs or Tecumseh you can get OS for. Greg

You are right, the mower is 25 years old, runs well, and I am just thinking of rebuilding it because I want to, not because it is absolutely necessary. The crank is slightly bent and if I can find a new crank this winter then I will put it in there. I need to decide if replacing the rings is worth my time.

Lawn boy oil has gotten me 25 years of service from this mower, I am not knocking it at all. Personnally I think synthetic is better oil, and I would use synthetic if I knew where to find it, etc., I run synthetic in my cars now because they seem to do so well.

Fish

Well I got a lack of skill in reaming a cylinder for sure. If you were my neighbor I would try this on my mower, but I am not sure what re-boring/re-reaming my cylinder will cost. If its over $40.00 for boring and for new piston and rings, well, I would have to consider the option. Do you know where I could get a quality boring on this cylinder in the columbus ohio area?

Should I consider NAPA for the re-boring? Where can I get the OS piston and rings?

Thanks, Tom

lawnboy oversize pistons are available from rotary,primeline,sunbelt ,stens.

Anybody even sell LawnBoy labeled oil any more? I thought since Toro took over the brand, they were using generic engines.

aem sends...

You can still buy it. Greg

Care to produce any part numbers? I can not find OS Lawn Boy pistons in my Stens catalog. I will have to dig for my Rotary catalog, but I know it is here somewhere! Greg

Have you looked for a short block instead of rebuilding? I don't know if they are available for that age of mower, but IIRC they were not that expensive. Also check around, somebody locally should have some junked out mowers laying around you could scavenge parts from. Greg

lucas,

I may be interested in going the OS piston/rings route, depending upon my conversation with the machine shop later this morning. I think if I can get it bored for under $50.00 I may go through with it just for the fun of it. Could you help me find the os piston and rings? I dont know a darn thing about sizing, and I dont want to have to rely on the guys in the shop, they may not have a clue.

Thanks, Fish

Does LB make any mower engines anymore? On the website all the models listed are powered by Briggs, Tecumseh or Honda. Seems like the only place you find the Duraforce (their updated reduced emission 2-stroke) engine is on the snowthrower.

I was never a big fan of 2-stroke mowers but I always liked that smooth hum from double the power strokes.

OT but when did Sears abandon Tecumseh for Briggs?

might want to ask your questions at

Lawn Boy dumped the 2-cycle engine in just the last year or so. EPA regs are tough on 2-cycle engines. IIRC, the Republik of Kalifornia does not allow them any more. Personally I love the LB 2-cycle engine. Low maintenance, no oil to change. In the spring, sharpen the blade, clean the filter and go. Sears has used B&S for years, even while using Tecumseh engines, but Tecumseh was their primary engine supplier. I believe Sears still uses either, depending on the equipment. Greg

Well frankly I'm surprised 2-stroke wasn't outlawed on everything but the smallest handheld equipment (leaf blowers, chain saws, etc.) long ago.

I have seen these short blocks for this mower, what is a short block?

THanks, Fish

A short block is an assembly of the crankcase , piston, con rod, and crankshaft. All new parts, just add your old carb, shrouds, flywheel, and ignition and you are ready to go, Greg

Thanks, Fish