# Runs only when primed



## trawson (Mar 13, 2018)

Hi All ...

New here ... a big storm coming tomorrow so I went out to make sure the snowblower worked. This is a Craftsman 28" 9 HP (247.88790). The electric starter just grinds and has for a little while, probably something stripped, so we have been starting it manually until we can fix that in the spring.

So today I find that if I use the normal manual start procedure -- open the choke, open the throttle, prime twice, and pull -- it starts and fires for 2 - 3 seconds, then dies. It does not restart if pulled again, regardless of choke position, though you can hear the plug firing. It always restarts --- and dies 2-3 seconds later -- in the same way if primed again. Keep doing that and it just floods.

I removed the fuel line connection at the bottom of the tank drained all the gas and refilled it with fresh gas, and I put in a new plug as the old one was somewhat blackened. This caused absolutely no change -- the behavior is exactly the same.

The obvious conclusion is it is not getting fuel through the normal route, only through the primer. There is only one fuel line so I don't see how it could be blocked, the primer and regular operation would use the same line -- right? So what would cause this? Could there be a straightforward remedy or is this likely to be a carb rebuild or something? Do I just have to bite the bullet and shovel tomorrow?

Thanks for any help,

Tom


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## arienskids (Jan 26, 2018)

your fuel line could be collapsing internally or your main jet could be plugged up. i would start by dropping the carb bowl and checking the jet then i would check to see if you are getting fuel flow at the other end of the fuel line


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## Sblg43 (Jan 18, 2014)

Sometimes, when an engine will only run for a few seconds, I will slowly keep priming for those few seconds, to see if it continues to run. Eventually, it may stay running on it's own without priming. Sometimes, it works itself out. If that works, you might nurse it through the storm. But that's just a band aid. 

A carburetor cleaning, rebuilding or replacing may be in order. If the fuel line is original and the machine is old, it's a good idea to replace the fuel line as well.

The electric start may be weak and not fully engaging the starter gear on the flywheel.


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## trawson (Mar 13, 2018)

Thanks very much for the quick replies. They matched my underlying vague idea but with much more detail than I can summon on my own. I appreciate the education.

I doubt I will be able to do much with the carb before the storm, it's too late tonight so it depends what conditions are like in the AM. I suspect shoveling will be the order of the day.

New carb for this machine is about $50 - $70 so that factors into how much time it is worth putting in to repair ...

Tom


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## cranman (Jan 23, 2016)

Drop the bowl..move the float up and down a few times....it may be stuck up and not letting fuel into the bowl. When the float is down, fuel should be pouring out of the carb.


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## arienskids (Jan 26, 2018)

new aftermarket adjustable carbs are around 10 bucks and take a half hour at most to replace


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## 1132le (Feb 23, 2017)

takes about 15 min to do a quick carb clean on a 9 hp tecumseh


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## trawson (Mar 13, 2018)

OK thanks!! I'll see if I can do any of this in the morning. I do have an enclosed garage to work in, though not heated, we'll see how cold it is.

Tom


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## trawson (Mar 13, 2018)

Good news and bad news here .

The good news is it's running perfectly.

The "bad" news is it had nothing to do with the carb. Took the carb cover off, tapped the bowl to see if that would free up the float, but didn't want to open it up all the way because I had a full tank of fuel and no shutoff. After a lot of work I got it started by pulling and priming a lot, but it ran very slow and rough. Tried letting it clean itself up and it started running slightly smoother, but still low power.

Then while hanging around waiting just on a lark I tried nudging the throttle linkage and bingo, full speed! The linkage is through a spring wire and corrosion was preventing it from moving when the throttle handle was lifted. With a little lube it works perfectly and starts easily.

So it really wasn't getting fuel, but the problem was a closed throttle, not a dirty carb.


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## gibbs296 (Jun 22, 2014)

Glad you got her going. The thought of cleaning up after a storm by hand is not a pleasant one!


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## Sblg43 (Jan 18, 2014)

:3tens:


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## HCBPH (Mar 8, 2011)

trawson said:


> Good news and bad news here .
> Then while hanging around waiting just on a lark I tried nudging the throttle linkage and bingo, full speed! The linkage is through a spring wire and corrosion was preventing it from moving when the throttle handle was lifted. With a little lube it works perfectly and starts easily.



No matter how well you lube it, over time it's going to rust back up in all likelihood. Best plan to replace it when you can rather than hang it up. I've had more machines than I care to think of with that issue, never found a long term solution other than replacing them.


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## cranman (Jan 23, 2016)

needle nose vice grips on the fuel line when you need a quick shut off........


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## Dannoman (Jan 16, 2018)

A fuel shut off valve would be a good thing to add on when you have a chance. That way you can shut the valve and let the machine run dry after using it.


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