My Tractor Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
I have an 8461 commercial that i picked up from the garbage about 7 or 8 years ago. Cleaned it up and got it running (just disassembled and cleaned carb and new fuel line) but now it refuses to start. Has been bullet proof until now. I have changed the gas (have not run it this year) put in a new spark plug (e3), checked for spark which looks good, completely disassembled carb took out everything and cleaned thoroughly. Compression is up to 120 with a full pull. Still nothing I fear a leak in the case some where. Is it worth tearing down further or am I missing something simple. Even if i pour a little gas in the carb it will not run. There are some pinholes in the muffler. Seems a waste to junk it but it may be more trouble than it is worth. Although I have not seen anything close to it being produced today.
 

·
Registered
Joined
·
2,534 Posts
Check for clogged exhaust ports and make sure the crank seals are seated.
 

·
Registered
Joined
·
4,418 Posts
Def. Do not scrap it. That is one of my favorite models right there.

I would agree with ODF, pull the muffler and see if the exhaust is clogged...

On another note, not saying this is your problem but i had a lawn boy with an E3 plug in it, it wouldnt start at all after a bunch of pulls. Put a Champion cj 14 plug in it and it ran.... Not sure if it was a coincidence or what...
 

·
Registered
Joined
·
351 Posts
Def. Do not scrap it. That is one of my favorite models right there.

I would agree with ODF, pull the muffler and see if the exhaust is clogged...

On another note, not saying this is your problem but i had a lawn boy with an E3 plug in it, it wouldnt start at all after a bunch of pulls. Put a Champion cj 14 plug in it and it ran.... Not sure if it was a coincidence or what...
probably already checked but didnt notice if you had, but have you checked for spark?? could be a bad cdi???

hope this helps!!
 

·
Lawn-Boy fan
Joined
·
256 Posts
Seems like you have everything to make it run....compression, fuel, and spark. Next, I would see if the fuel actually making it into the engine (spark plug getting wet?)? If so, it may not be a strong enough spark to ignite the fuel.

Are you positive the fuel is good? I know you said you changed it, but have you tried a squirt of starting fluid down the carb to see if she will fire at all?
 

·
Premium Member
Joined
·
5,747 Posts
Make sure the reed valves are clean. If they do not seat, you have no crankcase compression and the engine will not breathe, doesn't matter how much spark, cylinder compression, or how much gas you prime it with. Remove the plug and turn the engine slowly, you should feel a slight resistance as the piston compresses the crankcase charge, and hear a pop as the transfer ports are uncovered.
 

·
Registered
Joined
·
357 Posts
Had that happen to me once, I was using a 1976 vintage Lawn boy
Special and shut it off to take a break, came back and it would not
start , had spark ,had fuel but dang near pulled my arm off. So
I took the carburetor off of it to find an Earwig (beetle) had some how
crawled into my carburetor and got stuck under one of the reed valves!
That was a first for me and I would not have believed it until I saw it.
How it got past the air filter I haven't a clue! Crazy Stuff!!!!!:fing20:
 

·
Registered
Joined
·
1,977 Posts
i gotta go with the other fellas, possible reed obstructon,
clogged muffler,
& i use a plain ol cj-8,or ngk c5s
works good
 

·
nothing of interest
Joined
·
1,025 Posts
Had that happen to me once, I was using a 1976 vintage Lawn boy
Special and shut it off to take a break, came back and it would not
start , had spark ,had fuel but dang near pulled my arm off. So
I took the carburetor off of it to find an Earwig (beetle) had some how
crawled into my carburetor and got stuck under one of the reed valves!
That was a first for me and I would not have believed it until I saw it.
How it got past the air filter I haven't a clue! Crazy Stuff!!!!!:fing20:
I had one that sucked up a stick once, lodged the right side part of the reed open.
Don't know how the guy did it, but he did.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #13
Took the muffler off and everything looks good to me. I went and got acetylene for the torch but the puller pulled the collar right off easy peasy. Everything looks good to me besides the aformentioned pin holes in the muffler. The mower seems to be getting harder to pull and somtimes pulls back against the rope. This seems to be getting worse. Reeds looked good although I have not checked to see if they would seat properly although I suspect this is not the problem. There doese seem to be a little too much play in the crankshaft. I ran out of starting fluid cleaning the carb (i use that stuff mostly for cleaning) so I might try that later. I am thinking it must be sucking air in and this adding resistance that I feel when pulling. This is an important part that I left out earlier but it has been happening inconsisantly. It will pull fine and then on the 3rd or 4th pull it will almost get stuck and not be able to make a full pull. Any more suggestions and doese this warrent a full tear down although it is getting closer and closer.
 

·
Registered
Joined
·
2,534 Posts
Sucking air won't make it harder to pull. Sounds like you may have a flywheel key that's been damaged. That is if it's kicking back.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #18
The problem with the pulling happens even when the spark plug cable is not connected -so no spark. With no spark plug though it pulls very easy like it should.
 

·
4K Poster!!!!
Joined
·
5,064 Posts
Probably not timing then, I would squirt a little fuel mix directly into the cylinder and then see if it fires. If it does fire then you probably have a crankcase compression issue, ie upper or lower seal, reed leakage. Probably wouldn't hurt to put a compression gage on the cylinder to see just what kinda compression it is making on top of the piston.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #20
Took the carb off of the 8461 and put it on a 7351 that has been sitting for about 8 years (just for parts) and it fired right up and runs like a top. Mowed for about 2 hours today. You gotta love these old f,s. I think I have a major mechanical issue with the 8461 and I decided to tear it down and find out. I am having problems pulling even with out any spark. Thanks to everyone who helped I will start a new thread on the 8461 tear down.
 
1 - 20 of 20 Posts
Top