Craftsman mower won't start. Cleaned carb. What else to check?

ilyaz

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
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Choke carb is on the left, primer carb on right... on the primer carb you can see a small hole drilled below the top left bolt hole, that's where the air gets pushed into from the primer. Your choked carburetor doesn;t have that, so it will not prime.

So here's another photo. No cable or anything like that, plus a thread for some sort of bolt ("?"), so the whole thing does seem out of place.

Did I reconnect the spring correctly? ("??")

So from the looks of it, are my options:
1. Get a new carb. Would need a primer carb, not a choke one, right?
2. Permanently fix the choke in the closed position.

c.jpg
 

ilyaz

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
Put a piece of tape on the top that will hold the choke closed, and then try to start. It probably will.
But once it does, it will run very rich, unless you pull the tape off quickly.

Will try. But another thing I noticed earlier was that the spark plug was dry when I pulled it out. Do you think closing the choke like this will help with that?
 

Fish

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
Yes, the choke being shut causes a lot more fuel to get sucked up into the engine, kind of like a shot of gas from the primer...
 

Scrubcadet10

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
That threaded hole is only there because you have the wrong carb. thats the mount for the auto choke arm, which you do not have
you have the primer airbox, you need a primer carb. if you permantley close the choke, your mower will never run right.
The choke is only used when cold starting the engine.. just like when you press the primer it shoots extra fuel into the intake for easier starting.
And yes that governor spring is hooked up correctly, though once running you may have to stretch it to increase RPM.
 

ilyaz

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
Yes, the choke being shut causes a lot more fuel to get sucked up into the engine, kind of like a shot of gas from the primer...

That threaded hole is only there because you have the wrong carb. thats the mount for the auto choke arm, which you do not have
you have the primer airbox, you need a primer carb. if you permantley close the choke, your mower will never run right.
The choke is only used when cold starting the engine.. just like when you press the primer it shoots extra fuel into the intake for easier starting.
And yes that governor spring is hooked up correctly, though once running you may have to stretch it to increase RPM.

OK, so I closed the choke and it started right away. Seemed to be running OK although not perfectly smooth. So it looks like the problem is the wrong carb.

If I keep the choke forced closed like this, will I be burning too much fuel and putting more stress on the engine than needed? I am thinking of keeping it this way for now while looking for a salvage mower with a compatible primer carb to cannibalize. Or should I replace it ASAP?

Also, if I do end up buying a new carb, are there cheaper alternatives to SearsPartsDirect where I'm still likely to get the right part which won't fall apart quickly? Saw a bunch of what looked like fitting carbs on Amazon and eBay but don't know if I can trust them.

Thank you much for all the help!
 

Scrubcadet10

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
personally i haven't had good luck with the chinesium carbs, engines just a run a bit funky..., also, you may need to stretch the governor spring some to gain RPM, since these carbs dont have an idle circuit that feeds the engine at low rpm, if its running at low RPM, it may run rough.
Just search for briggs and stratton 799868 carb and see what prices you get.
But ultimately its your money, so you do what your finances allow you to.
Oh, did you open the choke after you started it?
 

Fish

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
Just use the choke to start it only. See if it stays running if you take the tape off and let the choke flapper spring open.
You could rig up a cable or pull to move the choke, so it can easily be opened or closed.
 

ilyaz

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
personally i haven't had good luck with the chinesium carbs, engines just a run a bit funky..., also, you may need to stretch the governor spring some to gain RPM, since these carbs dont have an idle circuit that feeds the engine at low rpm, if its running at low RPM, it may run rough.
Just search for briggs and stratton 799868 carb and see what prices you get.
But ultimately its your money, so you do what your finances allow you to.
Oh, did you open the choke after you started it?

The mower model is 917388521, so on Sears Parts Direct I am seeing part num 498170. Is this the same as 799868 ?
 

Fish

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  • / Craftsman mower won't start. Cleaned carb. What else to check?
Put up the model numbers off of your engine, the Sears site is not too reliable.
 
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