Is the Lawn Boy 5024 blade collar threaded?

[FuzzyDriver]

If you don't already have it, you should get a copy of the Lawn-Boy service manual. It will give you quick answers to most questions you have: 1950-2000 Lawn-Boy Service Manual
Yours is a D engine and I am familiar with F engines. The last bottom seal I replaced I had the engine out already, so it was super-easy to get to. If you search the manual for "seal" you'll find lots of information on seal replacement. You should be able to pick the seal out and slide it off the shaft since you have the collar off.

The only luck I've had with collar plate rework was one where the previous owner had put on a blade with holes that were too small to go over the ridges on the collar holes, which bent the collar evenly toward the engine. It sounds like you really had to booger yours up to get it off, so you should probably just replace it.

You mention the stiffener, Do you still have an original, flat blade on? Your photo has the blade off already, so I can't tell. If you've replaced the blade with a Tri-Cut blade (i.e.your blade is newer than 1982), you should not be using the stiffener and washer. Search manual for "9-15" (without the quotes) and you'll jump right to the page.

It goes without saying that since you are down there working on it already, you should clean your exhaust ports.

 

[kinsler33]

Thanks. I should be able to rebuild the collar if I can't find a new one. This mower is from 1975, and I did not post a photograph. My guess is that there's a lower plate that I can unbolt to get at the seal, for I cannot think of a seal puller that would pull a seal from a hole several inches deep--unless the seal was somehow displaced. The remnants of a fuel filter remain around the main jet, but rather than fight with parts I just installed an in-line filter on the gas line.

I'll report on further progress.

Mark Kinsler

 

[FuzzyDriver]

OK, good luck. Like I said, I haven't worked on D engines, and looking at your photo I see that yours is self-propelled so there's also that assembly in the way. Did you find the D-engine seal replacement procedure in the manual? There's a guy here that knows a ton more than me on these mowers, RivetS, Maybe he'll join the conversation.

 

[tom3]

Been a while but seems like on my mower the actual bottom of the motor is about an inch above the deck plate. Might be much easier if you just pull the motor off the mower?

 

[kinsler33]

My mower is the two-stroke non-self-propelled 'brick top' Lawn Boy, or Lawn Bo because the 'y' got obliterated by gasoline. The photograph was posted by someone else. The blade shaft pokes out of a fairly long snout at the bottom of the engine, and the bottom seal is a few inches inside said snout. You can take off the muffler and clean the exhaust port without removing blade or blade collar, but in this case I've got very low crankcase vacuum. I don't know where the leak is: I re-set the top seal, which had blown out of place and was hanging on the upper shaft (the rubber was fine, so I just sort of glued it back in) but that did not solve the problem. Wondering if the bottom seal could be at fault I did a test consisting of a plastic bag stuffed down the carburetor's craw and the air cleaner foam stuffed upon that. Surprise: the motor started and ran, albeit slowly. So it's getting air from somewhere: either through the lower seal or through the throttle pivots or perhaps somehow through the fuel primer plunger, which I've just thought of. Is that a possibility?

Mark Kinsler

 

[FuzzyDriver]

Oh, my. Until your latest post I was thinking that was a photo of your mower! You've got some good attention on your other thread, so I think I need to move to that one.

 

[kinsler33]

Oh, my. Until your latest post I was thinking that was a photo of your mower! You've got some good attention on your other thread, so I think I need to move to that one.

I finally removed the blade collar by drilling a pair of holes in it, bolting the thing to my heavy-duty puller, and using such brute strength as I can summon up at my advanced age. By this point the blade collar was about as bunged up as one could imagine, so I reinforced it with a piece of iron pipe and a lot of brazing.

The rest was more straightforward than I'd thought. I un-bolted the lower muffler casting and then the aluminum plate that lies under the engine. I also unbolted the engine itself--just three bolts.

To remove the lower seal I used a long sheet-rock screw to punch a small hole in the seal's metal housing and then drilled out that hole to about 3/32" or 1/8" or so with my hand drill. Then I firmly screwed the sheet-rock screw into the hole I'd made and used the claw on a crowbar (the claw on a claw hammer works, too) to pull the seal right out of the engine casing. Part of the seal seemed to have been damaged--the rubber had torn--so that might have been the difficulty.

After assembling everything I find that I still have fuel-delivery problems. The mower will run for a while while there's fuel in the bowl, but it won't stay filled. I replaced the fuel bowl drain with a nylon fitting that would accommodate some very thin clear plastic tubing, and this arrangement allows me to look at the fuel level in the carburetor bowl. (The tube is formed into a U-shape).

So research continues. I think I've still got a real air leak somewhere, so I've applied o-rings to the throttle-plate shaft and to top of the primer pump. I shall re-assemble things tomorrow and maybe matters will improve. Advice is always welcome.

Mark Kinsler (and it turns out that all my message notifications from this group were in my spam box.).

 

[FuzzyDriver]

Wow, you have gone through a lot of work on that mower. Good job so far! Be sure to use anti-seize on the color and threads when you put it back together, and torque it to 50 ft-lbs.