# new gx240 carb surging



## orangputeh (Nov 24, 2016)

frustrating when you take the time to replace your gx240 carb brand new and it surges.
no. it's not oem. 

$55 new. $12 aftermarket. Original carb is 30 years old and i plan to take it apart and thorough clean. it needs a new float or needle valve i think because it is slightly flooding . I already tried cleaning it out once and it ran fine yesterday for about 30 minutes but today it was spitting gas out of the breather tube of the valve cover again.

those 2 parts cost more than the whole aftermarket carb. i guess i could have just switched over parts from the new one and seen but i wanted to take the carb completely apart and do the whole thing. plus i never tried one of these aftermarket carbs. Have used OEM Honda carbs. was just curious on how well it would work. 

takes maybe 1/8-1/4 choke and runs fine but that is not the point. yes i put on the new gaskets.
But maybe i did miss something.


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## YSHSfan (Jun 25, 2014)

Likely an air leak or it is jetted to lean (not for a snowblower). 
Try swapping the idle jet from the OE carb (if they are compatible)


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## JLawrence08648 (Jan 15, 2017)

Carb surging is the result of something wrong in the low speed, partially clogged passageway, or rust, deformed needle valve.

Aftermarket carbs are not as good as the original, everything is cheaper, thinner, and many times a steel fuel bowl which you do not want! Please! However you can swap over your aluminum fuel bowl. But they are cheap and most times instant smooth running. On occasion you'll find a leaky one. I prefer to order from a company that has an 800#, check on Amazon or the internet, order from eBay.

If you are doing a lot of repairs at the least you need a carb cleaner dunk gallon. And preferably an ultrasonic cleaner, a somewhat powerful one. You test them with a piece of aluminum foil.


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## orangputeh (Nov 24, 2016)

YSHSfan said:


> Likely an air leak or it is jetted to lean (not for a snowblower).
> Try swapping the idle jet from the OE carb (if they are compatible)


i will try that first thing in the morning and check back.


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## orangputeh (Nov 24, 2016)

YSHSfan said:


> Likely an air leak or it is jetted to lean (not for a snowblower).
> Try swapping the idle jet from the OE carb (if they are compatible)


tried it but no change. maybe i should have cleaned the new carb before putting it on? It starts easy and runs great . just need that 1/8 to 1/4 choke. not acceptable .


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## RedOctobyr (Mar 2, 2014)

You shouldn't have to clean a new carb. The jet in it may be a little too small. I know there's been a lot of discussion about re-jetting recent Honda engines. Perhaps you can use some of that info, and get a slightly larger main jet for the new carb. 

After reading some of that thread, I looked around, and saw that you can get carb drill kits for ~$10 on Amazon. If they had the right size, that could be a useful thing to have available. You could likely use the drills to help check a jet size, as well as to open it. 

If you suspect an air leak, you can try to test for it. If you spray carb cleaner at where the carb mounts to the engine, that can be a way to check for air leaks at that location. If the engine sound changes when you spray, then it's drawing in air, and carb cleaner, at that spot. But this test may be tough with a blower engine. Without an air filter to help provide separation, it's easier for any "over-spray" to be drawn into the carb's intake, making it seem like you have an air leak, when you don't. I think I've also heard of people using, say, a lighter. Don't actually light it, just squeeze so it starts putting out butane, and move it around the carb/engine mount area. If the engine sound changes, you're pulling in butane. 

Obviously you need to be careful with either method. 

Also, if the carb float was sitting at the wrong height, that might be able to contribute to an engine running lean.


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