Lawnboy 8402 School me on this commercial mower with a Duraforce 2 stroke

andyd

andyd

Joined
Sep 25, 2004
Messages
9,877
Location
Marshfield , MA
I travelled 130 miles to acquire this 'jewel' listed on Craigs List Free Stuff. It has the orange tank and wheels on an aluminum deck with a capstan drive. The shroud is black with chrome grills. I have a couple F series LBs. This is my first Duraforce. Supposedly, it ran last yr. Quick scan over at the Tractor Forum and can't find much positive. Bad coils and plastic carbs. Haven't had a capstan drive since my first mower. I have no need for another classic LB, just couldn't pass up a free commercial All info gratefully accepted :cool:
 
There was a brand new lawn boy 2 smoke at the loca lhardware store for a couple of years and I finally went in to see if I could get a deal on it and it was gone !
 
I bought a new Lawn-Boy with a Duraforce 2-stroke when I got my first house in 03'. It went through a few coils and I replaced the carb.
The better Champion spark plug, not the basic one, last longer than the original NGK did. I gave the mower to my dad months ago and he didn't like pushing it and got a Toro Personal Pace.


I used Supertech outboard oil mostly. The spark plugs I used were the Champion EZ start and lastly the Champion Premium. I know everyone thinks NGK is better, whatever.
 
I’ve never heard of a Lawnboy 8402 with a duraforce. Can you post a pic of the mower ? When I look up an 8402 it shows it as a one year mower built in 1983.
 
2013ecof150 said:
I’ve never heard of a Lawnboy 8402 with a duraforce. Can you post a pic of the mower ? When I look up an 8402 it shows it as a one year mower built in 1983
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OOPs . Thank you. I found the Lawnboy Timeline https://www.lawnboy.com/en/about

F Series started in 1978 and the Duraforce in'98. So under that black shroud and chrome is a good ol' F series. I've got at least 2 of those on rotted steel decks. That makes this a keeper even if the engine is toast. :cool:
 
if that mower you have is in good shape, it’s definitely worth keeping and fixing. From the few mins of research I did they seem to be quite rare.

make sure to check the crank seals. On a mower that old it’s likely they leak, or have disintegrated altogether. Especially the lower seal.
 
2013ecof150 said:
if that mower you have is in good shape, it’s definitely worth keeping and fixing. From the few mins of research I did they seem to be quite rare.

make sure to check the crank seals. On a mower that old it’s likely they leak, or have disintegrated altogether. Especially the lower seal.
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Unfortunately, the deck is cracked behind the RF wheel. No big deal to fix but.. I pulled the plug and poured some MMO in. seems to have compression, but something is dragging. I'm hoping the drag is related to BBC, not internal. Recoil could be rusted and binding. The neat thing about the F series is that I was able to revive 3 of them just by cleaning up the carb/governor and magneto. Whatever, its going on the parts pile for now. :cool:
 
Just a little more idiot's delight. Got the 8402 to run on carb cleaner. Mag is OK. Won't run on fresh fuel and recoil starter needs attention. Back to battening down the hatches so Lee will pass us by. :cool:
 
I returned to the root of my Lawnboy jones over on My Tractor Forum's Walk behind sub forum. been a member since early 2000s I posted news of my find and, got some positive feedback. I asked about a service manual and one of the veterans gave me a link to a pdf. Looks to be a fun project for the winter :cool:
 
The My Tractor Forum walk behind section is probably the closest thing to a Lawn Boy forum out there, and sometimes I think they should retitle it that :)

A month and a half or so back, I visited the moderator of that section at his home/shop and bought two mowers from him along with a bunch of other LB goodies. He has quite the collection, along with some pretty amazing users. He had fun showing off his electric start Liberty(1976 red/white/blue painted and shrouded) which he uses weekly.

Really a great place, though, for Lawn Boy knowledge and I find it to be a really positive forum atmosphere.
 
I spent Saturday taking the engine apart. Most of time was spent spraying PB Blaster and oil onto the end of the crankshaft as I pounded on a 3/8 fine thread bolt to remove the clutch brakeI saw a you tube where a guy rehabbed a D series engine that had a stuck ring and scuffed piston. I was working on a 40 yr old FREE commercial Lawnboy. I figured it had been used to death. Taking this engine apart was a wasted effort. I can see cross hatching in the cylinder and both rings were free. I'm going to replace a few seals and gaskets and maybe get the crack heli-arced. I drilled the end of the crack and hope it doesn't get bigger for now. More later :cool:
 
andyd said:
I spent Saturday taking the engine apart. Most of time was spent spraying PB Blaster and oil onto the end of the crankshaft as I pounded on a 3/8 fine thread bolt to remove the clutch brakeI saw a you tube where a guy rehabbed a D series engine that had a stuck ring and scuffed piston. I was working on a 40 yr old FREE commercial Lawnboy. I figured it had been used to death. Taking this engine apart was a wasted effort. I can see cross hatching in the cylinder and both rings were free. I'm going to replace a few seals and gaskets and maybe get the crack heli-arced. I drilled the end of the crack and hope it doesn't get bigger for now. More later :cool:
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If you want to mess with Lawn Boys much, do yourself a favor and get a tool kit. Some of the tools in mine I have never touched and likely won't in the immediate future, but I know there's at least one if not a few purpose made tools in my kit for dealing with the BBC assembly.

They crop up on Ebay from time to time. There are some super handy things in there that you will use all the time depending on what you deal with, and of course some you may never use. Mine has the special tool used to set up the D engine governor, which makes setting one a 5 minute job that almost always gets them correct provided that nothing else has been messed with and your governor springs aren't fatigued(setting it is a trial and error affair if you don't have the tool). There are also oil seal pullers and seaters, and plenty of other things. I think I paid $150 for mine, and it's been well worth it for me even though if you only have a single mower it may be tough to swallow paying that much.
 
skyactiv said:
I bought a new Lawn-Boy with a Duraforce 2-stroke when I got my first house in 03'. It went through a few coils and I replaced the carb.
The better Champion spark plug, not the basic one, last longer than the original NGK did. I gave the mower to my dad months ago and he didn't like pushing it and got a Toro Personal Pace.


I used Supertech outboard oil mostly. The spark plugs I used were the Champion EZ start and lastly the Champion Premium. I know everyone thinks NGK is better, whatever.
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I have always had good luck with champions as well ! have been using them for 30 plus years in my ope.
And my old outboard always ran better with champions .
 
Yah that is what most of my F series came with. I broke the bottom ring GRRR. Luckily, I found NOS rings,seals, gaskets and a float, needle and seat kit. I had no problem finding the 6006DU bearing it needed too. Gonna splurge on a 1/4 torque wrench at HF..More later come November or so. :cool:
 
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