MF 65 throttle adjustment

masseyluver · Oct 27, 2022

I'm new to this forum so if I'm in the wrong place please let me know. I have a great running MF65 that I just picked up. The only trouble is that the throttle won't stay put. Run it up and when you let go it jumps down into idle. I tried adjusting the nuts on the plate behind the battery but nothing changes. I feel like there should be a friction disc on there or something but as it is everything just turns. I'll try to post a picture if I can figure out how. Thanks for any advice.

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Dieseltech · Oct 27, 2022

There's a steel disc between two cork friction discs. The throttle shaft has two raised keys that enter the two slots on the steel disc. When that area wears
or shears the throttle shaft keys off, throttle won't stay put. I have a crude, but permanent fix. Remove the oil pressure gauge, then the hold down parts and
shaft. Remove the two cork discs and if good cut through one side into the shaft bore and set aside. Replace the steel disc, spring, top plate and shaft. With
the steel disc down against the carrier, slide the spring and top plate up out of the way on the shaft. Now use an arc welder and weld the steel plate and
shaft in two or three places through the oil pressure gauge hole. After it cools replace the two cork discs and reassemble. I've done this on several 50 and 65
models, 165 and 175 too over the years and never have any more throttle trouble. Even if a new shaft and steel disc are used, it WILL get loose again, and
making the cork disc tension too tight makes the shaft and disc wear even faster.

Eric in IL · Oct 27, 2022

There should be two cork friction washers a metal washer and a star shaped friction spring. The slots in the metal washer that are supposed to have a good fit to the ears on the throttle shaft wear out and become a sloppy fit.

You can fix the fit by brazing or welding the slots shut and filing them back out for a snug fit.

jt501 · Oct 27, 2022

we had this problem on a gas mf65- turned out that the governor was sticking/frozen, and once it was freed up the idle worked as it should.

masseyluver · Oct 28, 2022

(quoted from post at 12:53:46 10/27/22) we had this problem on a gas mf65- turned out that the governor was sticking/frozen, and once it was freed up the idle worked as it should.

Thanks a lot. I'll give these ideas a try. I appreciate your expertise.

Felix5 · Jan 4, 2023

That sounds like a great fix. I'm pretty new to all this. If at some point you could share pictures of like what the fix looks like it would help me so much. I have no idea what it's supposed too look like under the dash but definitely feels like it's missing parts to have the throttle function properly on mine as well.

MF 65 throttle adjustment

masseyluver

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Dieseltech

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Eric in IL

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jt501

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masseyluver

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Felix5

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