Lawn boy crank seal replacement. anyone done one?

[matt167]

I recently picked up a freebie mower down the road. It was green and I knew what it was so I threw it in the truck..

It's about an '84- '85ish Lawnboy 7072 Special.. I cleaned the carb, stuck some fresh TCW3 mix in it, and it fired off in a few pulls, but exhaust and oil mix above the deck told me it needs crank seals... I mowed my ditch with it ( blown up 2 4 strokes in the past from it ) and it ran about 10 mins and runs itself out of gas, then will run another 10 mins after it cools.. Pretty much confirming that it needs a lower seal.. Anyone done one? I'm not sure the local mower shop will work on a 36 year old mower, even if most parts are available from Toro still

For those that don't know Lawnboy was an OMC product from it's beginning until the early 1990's when Toro bought the brand

 

[racerone]

I cut with a 67 model myself.----You just need the seal dimensions.-----I usually install a seal that is also used on an outboard gearcase..----Why would you say it needs a crank seal.-----Test for spark when it stops I say.

 

[matt167]

I cut with a 67 model myself.----You just need the seal dimensions.-----I usually install a seal that is also used on an outboard gearcase..----Why would you say it needs a crank seal.-----Test for spark when it stops I say.

I can prime it rapidly and get enough fuel into it that it it will fire up for a second, and it acts like it runs out of gas. Can hear it go a little leaner before just dying... The exhaust blows out above the deck and the deck is oily.

 

[GA_Boater]

Find you Lawnboy mower here for seal and other part numbers - https://www.partstree.com/search/?t...walk+behind+mower+1984+sn+c00000001+c99999999

 

[racerone]

Crankshaft seal has nothing to do with carburetor running out of fuel.----The exhaust blowing out on the deck might be the gasket between the cylinder and muffler !

 

[matt167]

I thought with a 2 stroke, a blown lower seal would make it not pull fuel? I would be sure that the muffler/ cylinder gasket is blown as well... For sure it's a fuel issue. 2 pulls and it comes to life cold.. I'll admit, I'm not the most well versed with 2 strokes.

Sure is nice and light for mowing the ditch/ bank.

EDIT: Sure is a carb problem.. It will run without a hicchup on the low speed setting, but click it to high and it runs out of fuel pretty quick. Since this carb uses the low speed jet on low I'm pretty sure, it makes sense it would run different