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Discussion Starter #1
Hi everyone,

My question is about an old MTD Ranch King that has some odd problems. I am already looking for its replacement, but can't stand it that I can't figure out what is wrong with this one. Hoping you all can maybe point me in the right direction.

There are two problems:

1. It acts like it is in super tall grass even if it's only like 6 inches high. The engine will slow down and eventually stall unless I disengage PTO or stop the tractor and let it "catch up."

2. When I go to shut the thing off with the key - it keeps running. I have to throttle all the way down and use the choke to stall it out. (replacing ignition switch did not help)

Problem 1 started first. I have no idea if the two are related or not.

I rebuilt the deck for this 4 years ago and put a new idler pulley on it this year - the blades seem to move as freely as they ever have. The carburetor is clean and linkage working. It throttles up and down fine. Runs like wildfire so long as I'm not cutting grass!

Thanks to anyone who wants to take a shot at either of these problems!

Sam
 

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1) 6" grass is really a lot of grass. This could be something as simple as dull mower blades or a heavily-caked mower deck. It may be that your governor springs are out of adjustment, however. You'd need to provide your engine model number ("######-####-##") for more help there.

2) Sounds like you have a break in your coil's kill wire. This black wire runs between the "M" on the ignition switch and the engine's coil. Trace the spark plug wire(s) back to their point of origin to find the coil which will be mounted at the periphery of the engine's flywheel, and verify that there are no breaks in that small black wire between that coil and your ignition switch.

Touching the small black wire to ground stops the coil from producing spark -- and that's what you want.
 

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Discussion Starter #3
Absolutely! Kill wire must have gotten damaged when I took off the front to do the spark plugs. Thank you!!!

The engine still slows down more than it used to. Six inches may have been an overestimate. It didn't take much.- certainly not as much as it used to. The deck is pretty clean. I seem to have found a sweet spot on the choke (much much smaller than it used to be) where it does the best. I will download the manual and look at what it has to say about governor springs next.

Thanks for the tip and I'll be back to let you know how it goes!

Sam
 

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any engine that has to be choked to run hard is typically a fuel-air mixture problem...carb...just bite the bullet and kit it. They're all easy to rebuild on the little briggs engines.
 

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Discussion Starter #6
Here is the S/N:

422707-1214-01

The model number of the tractor itself is completely worn away. So.... no MTD manual. I'm going to grab the engine manual though.
 

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It's very common for these carbs to plug up, and the fact that you have to choke it to keep it running suggests that that is what is occurring.

1) Remove the top air filter cover, air filter, and the long metal channel thingy that sits under the filter so that you can see straight down into the carb. You can leave the flat, bottom half of the filter cover in place. When the engine is running you should be able to watch gas coming out the jet, but we'll get back to that later...
2) Looking at the engine from the front, there's a hex plug on the right side of the carb near the front and bottom with an o-ring seal. Remove this; if you've been running the engine recently there should be a small amount of gas that pours out so be prepared to catch it.
3) If you can look up that hole you'll see the brass nozzle behind it with a small hole in the center. Take a thin copper wire (like one strand of a multi-strand copper wire) and stick it up this hole because it's undoubtedly plugged. You can also remove that jet with a screwdriver but it might be stuck tight.
4) Replace the plug, poor a tablespoon of fuel down the top of the carb, and start the engine. If you managed to unplug the jet properly it should run much better with less choke. If not, you'll probably need to disassemble and clean it -- take careful pictures of the governor linkages/springs under the carb so you get it hooked back up right.

Due to the design of the carb the jet just sucks up particles at the bottom of the bowl -- because that's where the jet's intake is. If you have debris in your fuel line you might need to do this multiple times. Being able to look down the carb (with your face a practical distance from it, mind you) you should be able to see how well gas is coming through it.
 

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Discussion Starter #8
OK! Clean the jet - tractor runs great for a while. Had to repeat a couple times but she has been going strong for a week with just a few sputters every now and then. The wire from a trash bag tie with the plastic striped off worked like a charm. Can't thank you enough because my deal for a replacement mower fell through. Now to replace that starter.... yeah, it's all busted. At least I know it will run great once I do. Thanks again :)
 
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