MF 135 Perkins Gas Carburetor Problem and Question

Hi List,

First, I am having what I assume is a carburetor problem (Zenith carb) with my 1974 135 Orchard model. It stopped suddenly during operation. After doing a basic check, I have a good spark and gas to the carb. This happened about two months ago, but then the tractor ran with no problem after sitting for a couple of days. Also, on another occasion there was gas running from where the air intake tube connects to the carb. I replaced a cracked hose (but I don't assume it that corrected the excess gas problem). Lastly, the wire that connects the carb solenoid to the starter is broken--and my attempts to solder it back to the solenoid were not successful, so it remains detached. However, if I am correct having the carb solenoid connected is not neccessary to run the tractor.

So, I have a carburetor problem, right? Any other idesa?

It seems that my options are either to rebuild the carb or purchase a new carb. Any others?

How difficult is it to rebuild the carb with a kit (I'm just a backyard mechanic, but reasonably intelligent). If it's tricky to get things adjusted correctly I'd rather have an experienced mechanic do it.

What are the pros and cons of rebuilding the carb vs. buying a new one besides the cost? If I choose to buy a new carb, any suggestions as to the best source?

Thanks for any info you can offer.

Rob from Washington (State)

Rob,The fuel shut off solenoid will work w/o wire
but won't do it's job to shut off the fuel,hence
the gas in the hose. We used to replace that fuel
solenoid with a 1754 158M91 "old fashioned" valve
and be done with the problem. I would almost never buy a new carb. Most often a genuine clean
with a long soak in carb cleaner, a needle &seat,
and gaskets will make it like new. Chuck

Thanks for the info, Chuck. In your opinion, is a carb rebuild something a novice mechanic should attempt, or should I have the local MF shop do it? I"m fairly mechanically inclined, but I"ve never done a rebuild before. Typically, I"ve found that the instructions that come with afer-market parts aren"t all that descriptive. Thank you for your help!

Also, Chuck, any idea where I can obtain the part you mentioned? I did an Internet search by part number including the AGCO parts book, and I didn't come up with anything. I'm thinking that if all else fails my local MF dealership should know--right? Any ideas will be greatly appreciated. Thanks!

Hi Rob, You can do it, nothing hi-tech and basic
outside adjustments would be in your owners man.
That part might have to be ordered thru dealer,or
poss no longer avail?? I would also check the $$
years ago the solenoid was expensive and the mech
valve was cheap but sometimes things turn around.
I always advise a good soak in carb clean-cleans
out the "lime" Check out auto supply or a garage
may agree to put in his "soaker" o'night. Chuck

Rob:

The solenoid is an anti dieseling solenoid that shuts off fuel flow to the main jet once the ignition has been turned off.

The tractor will run without a functional solenoid only if the tapered valve is removed (ground off) from the solenoid (if this has not been previously done, which is not uncommon due to the cost of the solenoid).

Disabling the solenoid will cause the engine to diesel (run on) after turning off the ignition switch, especially when hot. To minimize this, you will need to use the correct heat range plugs and adjust the idle to the recommended 350-400 RPM. It will also help to allow the engine to cool down a bit before shutting down.

Do not allow the engine to diesel upon shutdown as if often runs backwards, which, of course, means that the oil pump is alwo turning backward. You can, of course, stall it with the clutch.

Dean