LawnBoy Engine dismantling, cleanup and rebuild

[kibble]

Ok, per Russ's challenge, I am starting this thread to keep track of the work I will soon embark in related to the LawnBoy I acquired several months ago. In an earlier thread, I posted some pics of the engine and received some advice and tips from the master mind of the LB powered kart himself, Russ.

Work that needs to be done includes:

Dismantling of the engine to clean out carbon deposits and other debris I observed after removing some parts the first time.

Cleaning everything on the outside to make it look spic and span, for aesthetics mostly.

Reassembling the unit.

Adapting and attaching the Tillotson HL239B carb I bought for it on eBay.

figuring out a solution for the air filter.

Fabricating some sort of exhaust for the unit.

and making a mount so that I may attach the unit to my kart for testing once it's all up and running.

This is all I can think of for the time being. There may be some improv as I go along but that's to be determined.

Ok, Russ, how's this for a start? :toetap05: :arf:

 

[Russ2251]

Ok, ok. I leave you alone now.
As far as air cleaner goes, I used a Tecumseh unit with excellent results. Attaches to Tillotson without any mods. Washers are needed under carb mounting screws as they can interfere with choke shaft causing it to bind. Part number TC-730127 (attached pic). Available at www.m-and-d.com .
I later switched to an old L-B air cleaner only because I like the look of it.
Second pic is air cleaner mounted on Tillotson HL (Briggs 2 cycle).

 

[kibble]

That's a pretty nice looking cleaner, I went ahead and ordered one. Now I'll need a fuel tank too, but I kinda like the one you showed me before with the attached mount.

 

[kibble]

Dude, I've been searching and searching trying to find the post you put up about where to get that gas tank but I can't find it anywhere. Would you be so kind as to post the link where you got it? I would really like to get one like that as it would make things easier.

 

[Russ2251]

Found it here. Post #27:
http://www.diygokarts.com/vb/showthread.php?t=910&page=2

 

[kibble]

Awwww ghetto! It's from the same place and I already placed the order for the air cleaner!

 

[Russ2251]

Big arms...Small brain.

 

[kibble]

Big arms? What, are you checking me out?

Eh, it's alright, I emailed them to see if I can still add the item to my current order. If I have to pay extra, no big deal.

 

[Russ2251]

In the future, if there is something you're looking for, let me know.
Chances are, I have already researched and located it.
I am very familiar with old engine parts (as well as new) and I usually know what can/cannot be used/adapted.
Many different air cleaner configurations can be used "as is" or easily modified to make them work on Tillotson HL's.

 

[kibble]

Thanks man, I see you're not only good for harassing others.... :arf:

Anyway, I got to do just a bit of work today on the LB. Not much, just took off the head and the part of the engine that has the reeds on them. I'll post up some pics for you to analyze. I'll be drilling out the hole for the vacuum pulse now that I have it dismantled.

What do you recommend for using to clean the insides? What did you use to seal the fitting for the vacuum?

 

[kibble]

Ok so here's some pics. They should all be pretty self explanatory. There's one of what the reeds look like inside the crankcase, one of the cylinder where you can see the crosshatch marks, and one of the needle bearings on the piston rod. There's one of the piston at TDC. As you can see, it's only about 1/16 from the very top of the wall. Putting the head on with no gasket isn't a problem because it won't hit it. I'll use the stuff Russ said to use to seal it.

There's a lot of crusty crap on the piston and some on the head. I think they ran this engine with the wrong mixture of oil. The stuff on the head is crusted on the side where the exhaust port is. There's so much oil in there that the plug looks like it's fouled.

I need to give the insides a good cleaning.

Russ, what did you use to seal the crankcase back up? I noticed there's a really thin film of some sort of clear stuff, but it's not a gasket.

 

[Russ2251]

What do you recommend for using to clean the insides?

Kerosene and denture or tooth brush and disposable paint brushes.

What did you use to seal the fitting for the vacuum?

J-B Weld. Hole should be drilled slightly offset (toward flywheel, see pics). Offset will allow clearance for torquing of bolt that secures crankcase to cylinder. After hole is drilled, lightly sand immediate area around hole so J-B weld has something to grip on. Kind of like roughing up a tire tube before you patch it.

what did you use to seal the crankcase back up?

Refer to service manual. Says to use Loctite #515. Use same stuff for head gasket substitution.
DO NOT RE-USE OLD SEALS.
Please, please, please refer to service manual that you downloaded.

 

[kibble]

Please, please, please refer to service manual that you downloaded.

Yes, I was gonna do that, but now I gotta find it.

 

[Russ2251]

Incidentally, barb should be metal and not plastic.
If plastic, J-B Weld may not hold it securely.
Don't be chintzy with how much J-B Weld is used.

 

[kibble]

I bought some 1/4" brass nipples. that's similar to what you used, isn't it?

 

[Russ2251]

I bought some 1/4" brass nipples.

Perfect!

 

[kibble]

Got me some JB Weld today. I still need to find the 515 and kerosene, I don't have either of those.

 

[kibble]

Apparently, Kerosene isn't as easy to get as I thought it was. Can I substitute paint thinner for kerosene?

 

[Kenny_McCormic]

Apparently, Kerosene isn't as easy to get as I thought it was. Can I substitute paint thinner for kerosene?

Gas station? You could probably use some hoppes #9 gun cleaning solvent, its mostly kerosene with some ethanol and ammonia. I have used it to clean aluminum receivers without a problem.

 

[kibble]

Hmmm I'll take a look at a gas station next time I go.