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Discussion Starter · #1 ·
My grandson was given a nice Cub Cadet 122 with a K241 Kohler engine. Was able to get it running fairly easily by cleaning carb and cleaning and setting the points. The problem we are having now is that if you crack the throttle the engine stalls. If we open the throttle slowly the engine takes the gas and runs fine. The carb is clean and is getting plenty of gas from the tank. I've had this problem with other engines in the past and was able to correct the problem by adjusting the carb. No matter how I tweak the high and or low adjustment screws the problem stays the same. I'm thinking could it be a leaky intake valve? The engine starts up easily hot or cold, and the problem exists hot or cold. Usually a valve problem will show up with hard starting at some point. I might add that it looks like a new carb. The previous owner had it set up as a pulling tractor and seemed well maintained. It had sat for about a year though with out being started.

Figured I'd ask you guys cause someone might have a simple answer.
 

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I am not questioning your carb cleanliness but if it was mine I'd tear it down again and check the low and high speed jets. I have a k241s engine in a wheelhouse and have had to do it before. I think it is easy to loosen trash, not get it all out, and it finds its way to a new resting place.
 
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I had to clean my onan carb out three times because I didn't fully clean it, I didn't blow it out to get all the particles of cut rubber out when I changed fuel pumps.
 

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Discussion Starter · #4 ·
Hopefully you guys are right. I was able to actually see through and feel air through all the holes, but you are right. It is worth another look at the carb. A trick I've learned is to stick the carb and parts in boiling water. It does its work in all the unseen places, and water won't hurt anything while removing dirt that petroleum based products wont dissolve. Thanks for the reply.
 

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Discussion Starter · #5 ·
Ok, It took a while but I figured out what was wrong with it by putting two problems together I've had in the past with full size tractors. One of the tractors had a new carb on it that turned out to have too small of an inlet hole in the needle and seat, causing the tractor to not get enough gas under load. The other tractor had a miss adjuster high idle screw causing it to not take gas when throttling up. Anyhow I came up with an original carb off of a junked 122. I compared the inside parts of the two carbs. The high idle needle screw and its mating part had larger holes in them than the other carb. using the larger parts fixed the problem. Lesson learned: If one buys a new carb compare the internal parts!
 
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