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Lawnboy 6431 won't start cold

16 years ago

So, in another post, I related how happy I am with my old '87 LB after unplugging the exhaust ports thanks to info found on this forum.

Perhaps someone can troubleshoot this new, minor, but annoying problem. My mower refuses to start when cold . . . when it has not run for a week. In order to start it, I have to tip it on its side, take out the plug, squirt a drop or two of fuel into the cylinder, replace the plug, and pull the starter cord. It will start on the first or second pull in this way. Once it has run, I can start it even when it has nor run for an hour or so. Even when hot, it won't start unless I choke it, and that seems a bit odd to me, also.

I know the choke is functional, because, when running, if I move the throttle control to the choke position, the engine will flood out and begin to stall until I return the throttle control to its normal position.

So, what do you think is causing this behavior and how do I correct it?

Having to prime when cold isn't a huge demand from a 21-year old mower, but it is less than gracious. I'd like her to be perfect if possible.

Suggestions welcome.

Caruso

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Comments (7)

bill_kapaun
16 years ago
I'd physically look at the choke plate to make sure it's closing all the way. If it's open just a little bit, it may cause problems. When it's running, you have much higher airflow. Starting with minimal air flow through the carb is a different dynamic.
carusoswi
Original Author
16 years ago
Will check it physically this weekend.
Thanks for the reply.
Caruso
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j0nes
16 years ago
Try taking the air filter off ... if it starts, then you have a clogged air filter ... Also try replacing the spark plug. You can also pull the coil off and sand down the contacts and sand the magnet on the flywheel ... It will help it fire alot better. Good luck
walt2002
16 years ago
I believe a clogged air cleaner is going to have the opposite affect he is experiencing, also, a little rust does not affect electro magnetic flux, there is no contact point.

Choke is not fully closing.

Walt Conner
walt2002
16 years ago
Well contact area where coil mounts, yes.

Walt Conner
1saxman
16 years ago
So that model is choke-start only, no primer button? I guess that's why they put the choke AND primer on the Duraforce.
carusoswi
Original Author
16 years ago
Well, I won't be able to check this until the weekend, but, I did have the carb off the machine twice during my trouble shooting a couple of weeks ago - perhaps I goofed when re attaching it.

OTOH, it's probably been years since I started that mower using just the choke. I always attributed the problem to old gas in the fuel line.

Now, I'm thinking that some little thing may have gone bad over the years that, with correction, will solve this problem.

It's not a biggie to me, but, now that I have her running so well, I'd like to cure this if possible.

Thanks for the replies.

Caruso

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