sputters on full throttle
 

Cub Cadet 2007 SLT 1550 Lawn Tractor. Kohler Courage 25 Horse. sputters at full throttle and smooths out with choke. I think it will die under a load. New $40 carb. new gas line from tank to carb. I've read about drilling out "Welch plug: to find adjustment screws and adjust high - low settings like a chain saw. I don't know and can't find where to do this. Screw on top and side don't change problem and I admit I don't know what they are for. I can adjust my chainsaw and weed eater but I can see the adjustment screws and find instructions if I forget which is which. Can't find a video on this $40 carb- how to drill $40 carb; just weed eaters . I think I need to see one like mine. Anyone here familiar with this procedure and problem? Thank you for your time.

Cub Cadet 2007 SLT 1550 Lawn Tractor. Kohler Courage 25 Horse. sputters at full throttle and smooths out with choke. I think it will die under a load. New $40 carb. new gas line from tank to carb. I've read about drilling out "Welch plug: to find adjustment screws and adjust high - low settings like a chain saw. I don't know and can't find where to do this. Screw on top and side don't change problem and I admit I don't know what they are for. I can adjust my chainsaw and weed eater but I can see the adjustment screws and find instructions if I forget which is which. Can't find a video on this $40 carb- how to drill $40 carb; just weed eaters . I think I need to see one like mine. Anyone here familiar with this procedure and problem? Thank you for your time.

Not to offend, but I think before you attempt to learn about attacking a carburetor with a drill,
you should focus on learning about dis-assembling a carburetor and thoroughly cleaning one.

"new $40 carb" So did you buy a carb specific for your Courage 25hp or did you just buy a carb that looks like your oem carb ?

Thank you for your reply
 

No offence taken. I went through the original carb several times with success. Then it started corroding. Then I rebuilt the automatic hydraulic transmission and that was 10 years ago. (special thanks to the ace that explained why I didn't see anything wrong with it. Great Guy. Still no problems. Could I do it again? probably, but it would be like the first time. My car is 20 years old and other than tires; no one has touched it but me. The instructions in how to post on this site said to be honest, so I admitted and thought I might get a better by answer having done that. Most answers to questions on other site as well, leave out things they assume I should know. (opposite to what you said But you have a right to your own opinion. I've said things and was asked to keep my opinions to myself. I used the wrong words to say- not everyone has the $ to do it the way you are suggesting. So don't worry about it.
P.S: So, what are those 2 screws for?

Thank you for your reply
 

Yes, made sure the numbers were right and it showed Cub Cadet SLT 1550. I found videos of other carbs and where to drill, but not this one. I don't want to guess on something like where to drill.

I have never worked on, not seen a carburetor that has adjustments under a welch plug.
All welch plugs that I have ever removed are simply meant to seal a chamber where two or more straight passages running at different angles come to a confluence at the exterior of the carb body.
Granted, when the plug is removed the passages revealed can be drilled for cleaning or to be enlarged but there is nothing adjustable in there.
Mainly the plugs are removed to clean the passages that are exposed. Drilling or punching a hole in the plug, which is soft metal, is a common way to remove them.
Once removed, the plug must be replaced with a new one which can be a PITA to find one of the proper size. Some rebuild kits provide them, some don't.
Since yours is a new carb, it is possible there is manufacturing debris lodged inside some where. I'd try dis-assembly and lots of poking and probing with thin wires and compressed air.

I'll just add my expierence with inexpensive carbs from various non USA built.
Its a 50-50 bet.
Some work well others are not even close to working properly.
If a carb with the choke activated, works as it should, it is displaying a lean condition.
Lean can be caused by a blocked passage, or a wrong main jet installed, or a poor copy of an OEM carb.
Without seeing your carb or being familar with it, I cannot help you with adjustments.
At $ 40 it does not lead me to have much confidence it is quality built and correct for the application.

I have purchased little inexpensine carbs for weed wackers and some are correct right outof the box with not even needing low/high/idle screws adjusted, others will not run correctly no matter what ones does.
My experience is the bad ones can't even be used for parts because the fastners are metric not SAE so they don't fit.
Just my take on what I've seen.
In your situation, I would try to use your oem carb if at all possible.:bigthink:

Do you have a fuel pump or is the fuel system gravity feed ?