300:1

[bwalker]

I can't recommend upping the speed if you are doing it for someone else for liability reasons Blade tip speed needs to be to factory spec so you are covered if something gets thrown from under the deck or out the shute and hits someone/something

Its my personal mower that gets used at my house by my FIL due to the fact that I am gone all summer. I run it maybe three times a year in September when I am home.
I also have the mulch blade and fan wheel setup on mine so debris isnt as much of a issue.

 

[bwalker]

BTW I never realized it till today but LB has a "air injection" type air cleaner setup like Husky. The air box draws its air from around the flywheel.

 

[Al Smith]

The big end rod bearing is a cage less needle bearing that run s on a silver/babbit shell type bearing instead of running on the crank

Well,ok Ben,here we go again.Do the bearings run on the babbit or the crankshaft?Now,bear in mind I'm not picking on you,as I normaly do.However,silver or not,babbit is soft,needles are hard.How,pray tell would this work???I do not know of any babbit harder than navel brass,this would not be hard enough for a needle bearing.Needles balls or what ever,have to run in a hard race,Just the way it is.

 

[PES+]

I think the insert is chrome and it goes in the rod

WE do need a splitting hairs smilie

 

[dtnodya]

32, 40, or 50:1 will all work fine. I run 40:1 and don't really have a good reason why. I know that on older saws, most of the people that I learned from used to use a lot of oil in the mix. These folks (for the most part) still have excellent running saws that are OLD!!!

But I run 50:1 sometimes too ... If a saw manufacturer recommended 100:1, I would not do it. :Eye:

 

[RiverRat2]

I suppose I would try it @ 75 or100:1

with my Pull on or homie!!!!!!!!!!!!!!!!

But only after one of yall did it first LOL

 

[bwalker]

Well,ok Ben,here we go again.Do the bearings run on the babbit or the crankshaft?Now,bear in mind I'm not picking on you,as I normaly do.However,silver or not,babbit is soft,needles are hard.How,pray tell would this work???I do not know of any babbit harder than navel brass,this would not be hard enough for a needle bearing.Needles balls or what ever,have to run in a hard race,Just the way it is.

The big end of the rod is encapsulated in a shell type bearing that has a hard coating of what looks like silver, but could be chrome. Under neath this silverish coating is a soft material that looks lead based/ie babbit and underneath that is a metal shell. The needle bearings ride on this shell and on the crank journal.
I have no idea why they did it this way.
I rebuilt a ww-2 surplus gen set once with real babbit/cast on bearings. I had a heck of a time finding a place to re cast them
et

 

[Al Smith]

Perhaps it was done that way to provide a type of shock absorber to protect the needle bearings??? One of the short falls of needles or balls for that matter is the inability to take a shock load like a plain bearing.If you think about it,a lawnmower would in fact put a temendous shock load on a connecting rod.Due to the fact that a 2 cycle engine does not provide enough lubrication to oil a plain bearing,this evidently was the method they used.

 

[jhellwig]

The big end of the rod is encapsulated in a shell type bearing that has a hard coating of what looks like silver, but could be chrome. Under neath this silverish coating is a soft material that looks lead based/ie babbit and underneath that is a metal shell. The needle bearings ride on this shell and on the crank journal.
I have no idea why they did it this way.
I rebuilt a ww-2 surplus gen set once with real babbit/cast on bearings. I had a heck of a time finding a place to re cast them
et

That is the was most all lawnmower engines are made. No need for anything of the roller needle or ball variety when there in no side load.

 

[bwalker]

No need for anything of the roller needle or ball variety when there in no side load.

They use roller also. In other words a plain bearing and roller bearing on the same journal.

 

[jhellwig]

Oh I see now. You said there was a bearing in there also.

I was reffering to the numbers upon numbers of briggs engines out there with nothing but metal on metal.

 

[Al Smith]

Yes indeedy but a Briggs engine is a 4 cycle,oil in the crankcase,splash lubrication using an aluminum or brass rod,depending on the age of the engine.

A Lawnboy is a 2 cycle engine,oil in the fuel,not nearly enough lubrication for a plain bearing.

 

[PES+]

Update.....I was shaking my head

The new Jiffy ice augers with the Tecumseh 2-strokes have a plain bearing in the big end
There is one over at the local J-red dealer and we had trouble looking up the parts as he is waiting for the new parts mart relist and the last micro fiche is missing the later models of 2-strokes