Speed control messed up

[rigoletto]

MTD Rider, from 1998. Speed stick goes from 1-6. Lately any setting from 1-5 goes sooo slow, like never before. The difference between 1 and 5 is hardly noticeable, and when going up a slight hill the mower almost stops, until the ground levels out and mower speeds up a bit again. BUT when speed stick is placed on setting #6, the mower takes off like lightning! Sheesh- at 5 so slow, a tad faster than 4, then at 6 , look out! Why does it do that?

Thanks, people.

 

[bertsmobile1]

Time for a pair of new transmission belts

 

[rigoletto]

Time for a pair of new transmission belts

What do they call transmission belts on the parts list? Drive belt? I do not see anything listed as transmission belt. I do see a V belt on the list.

 

[rigoletto]

Then there also TWO different variable speed belts. Which one? My MTD is model 13A4667 F118, if that helps. Thanks again.

 

[StarTech]

MTD 9540280A Engine to Variable Speed Pulley
MTD 9540370 Variable Speed Pulley to Transaxle

Highly recommend buying MTD OEM belts as these mowers are very picky on their drive belts.

 

[bertsmobile1]

Both of them
Vari drive belts must be replaced as a pair.
Get them from a mower shop or a dedicated mower parts retailer, either shop front or on line .
I usually fit Stens or Gates belts that are exact OEM dimensions

 

[rigoletto]

Thanks, but those #'s are not listed in my parts diagram. I show 754-0370 and 754-0280.

But why does my speed #6 go fast as heck if my belts are old? One was replaced last year and I mow only about 8x per year.

 

[StarTech]

Thanks, but those #'s are not listed in my parts diagram. I show 754-0370 and 754-0280.

But why does my speed #6 go fast as heck if my belts are old? One was replaced last year and I mow only about 8x per year.

MTD superseded the 754 prefixes to 954 prefixes several years ago but many IPLs still haven't been updated to the new numbers. And "A" suffix is a newer revision of the part.

And as said both belts needs to replaced as a set. Just replacing one or the other is just leads to problems later as one that not replaced will give problems. Besides it only take a little longer to replace both at the same time. This way if a shop doing the work you only get charge for labor once not twice.

And it is just physics as I personally have this happen here in the shop too with my personal mower where it would not climb a slight grade except in the top speed setting.

 

[rigoletto]

So good to know as I never knew that. So, I will order both belts using both NEW #'s above. Will report back with results!

 

[rigoletto]

Wow, a year already!! I did install the new engine to variable speed pulley belt, a Stens. And wow, so much better! The other bely had only been replaced recently, so I didnt bother. BUT, Now, where before just about all speeds from 1-5 were sluggish, and 6 speed sent the mower speeding out of control, now all speeds behave nicely! Except 4!! Why is it that speed @#4 is behaving badly, meaning when the mower reached a slight incline, it almost comes to a stop. Sheesh! Then I put it in 5th, and all goes well. Speeds 1, 2, 3, 5, and 6 react predictably, as in going a bit faster, but #4 forget it! I dont get it, people. It actually comes to a dead stop on approaching a slightest incline.