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Chris727

Command Sovereign runs on choke only

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Chris727

I have installed a CH18 into my 75th anniversary tractor. It runs on choke only (or if you hold your hand over the carb creating vacuum). The fuel pump is working and I have even tested with a gravity fed tank held above the engine. I have since cleaned the carb (it was already spotless) and the situation has not improved. I can hear the fuel solenoid clicking so I know its getting power. What I don't know is if the plunger is pulling in. Will these run on choke even if the solenoid is closed?

Thank You.

Chris

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RayS

They won`t run with the solenoid closed. I am betting Brian is correct on a plugged passage. A Command that I bought a couple years ago that sat for 5 years with out the gas being drained acted the same way.

I took the top off blew it out with air. I used one of those needles used to inflate basket balls. Soaked it in BLT`s cure all Seafoam and it runs great. Just maybe luck though.

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farmtoybuilder

My guess is blocked passage in main jet or carb still! But as Ron and goatfarmer mentioned check for leaks at manifolds as well. Did you soak it overnight in carb cleaner?

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Burntime
quote:Originally posted by RayS

They won`t run with the solenoid closed. I am betting Brian is correct on a plugged passage. A Command that I bought a couple years ago that sat for 5 years with out the gas being drained acted the same way.I took the top off blew it out with air. I used one of those needles used to inflate basket balls. Soaked it in BLT`s cure all Seafoam and it runs great. Just maybe luck though.


id="quote">
id="quote">Bob finally came around to seafoam? I thought he was all about stabil? Guess once you use it you realize its "magic in a can!"

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Chris727

I never had the manifold off the engine. As far as the inside of the carb, its a Kehin singe barrel carb and is a pretty simple design. If I recall there was only one removable jet and I had it out and put new o-rings on it. There was no dirt or varnish visible before cleaning. No I did not soak it overnight. That would probably ruin the plastic choke lever (which I had broken the tip off of and had to install a new $40 shaft kit to replace). I suppose I will try spraing around the base of the carb with some cleaner to see if I can ID an air leak, if not the carb will be coming off again.

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BLT
Originally posted by Burntime
quote:
id="quote">Wrong got misinformed again. I stay ahead of my carb problems with Stabil and use Seafoam as a door stop that I won as a door prize.:D

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RayS
Originally posted by BLT
quote:
id="quote">Wrong got misinformed again. I stay ahead of my carb problems with Stabil and use Seafoam as a door stop that I won as a door prize.:D
id="quote">id="quote">I couldn`t resist. I knew I would get a response out of you even if it took you awhile:D.

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Chris727

UPDATE:

I had a siezed CH25 sitting on the floor with a Kehin carb. It was slightly different but I tried swapping the solenoids (same) with no change in operation. Finally I swapped the entire CH25 carb over to the CH18 in the Sovereign. The unit would now run properly without choke at a range of RPMs. The CH25 carb is similar but has an accelerator pump and an idle mix adjustment (from a much older engine). I took the CH18 carb apart again and no dirt was found and passages all blew through clean. I am not sure the removable emulsion tube is installed properly. Further investigation is required.

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fishnwiz

You need to be sure that the emulsion tube is clear and all the tiny holes clear and be sure that it is screwed all the way in and down tight.

Best of luck

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CVSB10JCS

I have a question...how do you adjust the carb with everything put together? My Command 18 runs rough and i put a new air cleaner & pre filter on but still dont see how to get at the screws if there are any???

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Chris727
quote:Originally posted by CVSB10JCS

I have a question...how do you adjust the carb with everything put together? My Command 18 runs rough and i put a new air cleaner & pre filter on but still dont see how to get at the screws if there are any???


id="quote">
id="quote">Most of the newer engines do not have adjustable carburetors. You may need to clean it out. My much older 25hp carb has an idle mix screw and it is accessible through a hole in the carb solenoid bracket. My 2007 engine does not have any mixture adjustments.

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CharlesC

All, just wanted to thank you for the information in this thread. I bought a late 90s sovereign with a kohler ch18s just last weekend. Looked it over and test drove with no big issues observed. However, after the 2.5 hr trip back, the engine surges or governor hunts with the choke open. Read some articles online here and on my tractor forum, then pulled the carb off on Friday. I pulled the carb off, did not disasmble it, drained it, clean it out with carb cleaner, and tried to clean & blow out the open ports on the top of the carb. It runs a little better, but still surges if the choke is open more 1/3.

Hopefully, I'll have time next weekend to remove and tear down the carb. I do have one question though. Is the gasket between the upper and lower halves reusable? I doubt it, but I have reused them on several Briggs L-head engines. I need to look for a gasket and other softwoods kit for the carb.

I've also ran about a gallon of gas thru with sea foam while,working this weekend. I did notice that the engine seemed to run hotter, so I took it easy.

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RayS

The upper gasket on mine is an O-ring. I had issues with my Command because it sat about 3 - 4 years before. I bought it. I took the top of and blew out the ports, reused the o-ring and reassembled it. I haven`t had a problem in the past 2 years since I don that. If you haven`t destroyed the o-ring you can reuse it. I reused mine and haven`t had a problem since.

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