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J.R., Small Engine Technician
Category: Small Engine
Satisfied Customers: 7445
Experience:  Owner of outdoor power equipment business, repairing all makes and models.
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I have a year 2000 Craftsman riding mower. Model No. 917.271050.

Customer Question

I have a year 2000 Craftsman riding mower. Model No.NNN-NN-NNNN Power plant is the single cylinder 15.5HP Kohler Engine (CV-15) with a Walbro LMK Carb.

I have been trying to get it to run properly for a few days now.

Symptoms: Tractor will start fully choked but die when choke is opened....however...if I drop the throttle bar from fully choked all the way to idle it will remain idling quietly with no issue.....the other symptom worth mentioning is that while fully choked I can stuff a rag in the air intake in an attempt to snuff out the motor and it will continue to run...suggesting its getting air from somewhere else?

I have performed the following maintenance to try and correct my issue:

- fresh oil change to 10w30 Castrol (synthetic)
- new plug Champion RC12YC
- New Kohler brand air filter and pre-cleaner
- new kohler fuel filter
- new kohler oil filter
- new fuel shut off solenoid
- new battery

I have pulled the carb and hit the inlet pickup with carb cleaner and can see the carb cleaner coming out of the sprayer...looks fine? Regardless the carb is bathing in a carb dunk tank as I type this. I ordered a new carb rebuild kit this morning (so it will have fresh gaskets) and got some fresh fuel line to try as well. I also plan on trying brand new high octane fuel (I may have mixed old and new fuel...I don't recall).

Would appreciate it any input to help get this mower working properly. If these final upgrades fail...I suppose my next purchase is a new carb?
Submitted: 6 years ago.
Category: Small Engine
Expert:  J.R. replied 6 years ago.
I think the problem is in the carburetor. Let me know what you find once you have it back together and we will go from there. The carb is the first place to start.
Customer: replied 6 years ago.

I agree the carb is the first place to start...but I'm not ready to rule out other culprits. With respect to the carb....if it idles well (as my tractor does) I'm guessing I really just need to concentrate on the main jet as this is what seems to be not working correctly (although I can watch carb cleaner spray out the main without issue).


I'm letting the carb soak for 2 hours, hitting it with carb cleaner then compressed air...then repeating this process. I plan on doing this for much of the next 24 hours. If I'm gonna clean this bad boy I need to know I did a thorough clean so I can potentially rule the carb out soon.


Any other tips of the trade you can share to help bring this mower back to life?

Expert:  J.R. replied 6 years ago.
The only other thing you may want to check is the valves. With it running with the choke On, but not off still says that it is a carb problem. Let me know.

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