1980 MTD 918 - 'Ol Rusty!

Brianator wrote:

You'll need to replace the trans pulley regardless if you're scrapping the VariDrive, the groove is designed for 11/16" wide belts and regular 5/8" belts don't tend to grip them so well. How fast you want to go? A 6" in the rear and a 6" on the engine should get you to about 11mph with 25/26" tires, put an 8" on the engine and you should see 15mph. I wouldn't go much more extreme than that, apparently 2300s don't like being oversped TOO much although I don't understand why after seeing inside of one.

Thanks for the link!

No problem!

Ahh shoot, I already bought a 6.75" OD pulley from Princess Auto, the 6.75" was cheaper than the 6.25" so I said what the heck. Pulley on the transaxle is about 7" OD.

The Princess Auto pulley can take A or B belts in addition to 4L & 5L. Seems "B" belts are 21/32" wide so closer to 11/16" than 5/8" maybe that'll be okay for now if I can find one?

Yeah sitting on 25" tires for now, I'm not sure on top end speed, this isn't gonna be a racer.... Yey maybe lol. Think I'm good with 20Kph or about 10Mph. Still need to see how she handles before I go cranking up the speed.  

Did you get cast iron or the weld on pulley? I've had great luck with the weld on ones and like that I can tack and test them before fully welding. Have you removed the trans pulley yet? I could be splined, keyed or tapered shaft, hopefully it's keyed but if it's not I can probably help!

My experiences with the VariDrive pulley vs 4L/B belts is just that, MY experiences maybe your pulley would handle it better than mine? I will say yours looks like it's more vgrooved than mine which is more flat than V so it's worth a try! Crank up the speed, you have low gears in the trans to keep it at a comfortable level until you get used to the machine and do more upgrades.

Are you considering entering the Build Off? You definitely qualify

Brianator wrote:

Did you get cast iron or the weld on pulley? I've had great luck with the weld on ones and like that I can tack and test them before fully welding. Have you removed the trans pulley yet? I could be splined, keyed or tapered shaft, hopefully it's keyed but if it's not I can probably help!

My experiences with the VariDrive pulley vs 4L/B belts is just that, MY experiences maybe your pulley would handle it better than mine? I will say yours looks like it's more vgrooved than mine which is more flat than V so it's worth a try! Crank up the speed, you have low gears in the trans to keep it at a comfortable level until you get used to the machine and do more upgrades.

Are you considering entering the Build Off? You definitely qualify

Cast iron sheave pulley, the one that tightens on the shaft as you tighten the bolts.
I'll definitely give it a try with the belts, maybe I'll be lucky!

Never thought about the build off to be honest! What's involved?

Oh you used Tapered lock! I've considered it to be honest but it's more expensive than the weld on ones so I haven't.

You can check out the rules HERE and see if it's up your alley! It could be the last one for awhile as interest has waned in recent years so it could be your only chance. The jist of it is that you have 11 months to build the baddest rig but you need to actually BUILD a tractor not just tear one apart, put it back together and do a few a few small mods to it. Your tractor is in shambles (no offense intended) and incomplete so in my opinion it's the perfect canidate to enter, you're going to build it anyhow right....? Lol

Budgie was not a native vari drive tractor but was a native jackshaft belt twist setup, with about the same frame and trans as your tractor. Clutch build started at about this post and went on in the thread:

https://www.atltf.com/t5779p100-mtd-budgie#93444

I have a video from when it kind of broke hahaha. Hope it helps. Please bear with me as I was worse at explaining things back then than I am now haha

Threw up another old video in case it might be of any use to you. This was an excellent feeling clutch with a very linear slip-to-catch. Probably my favorite clutch I've built to date.

Brianator wrote:

Oh you used Tapered lock! I've considered it to be honest but it's more expensive than the weld on ones so I haven't.

You can check out the rules HERE and see if it's up your alley! It could be the last one for awhile as interest has waned in recent years so it could be your only chance. The jist of it is that you have 11 months to build the baddest rig but you need to actually BUILD a tractor not just tear one apart, put it back together and do a few a few small mods to it. Your tractor is in shambles (no offense intended) and incomplete so in my opinion it's the perfect canidate to enter, you're going to build it anyhow right....? Lol

Ahh okay, I'll check it out!

Yeah the taper lock pulley was about $37 all together, not terrible but yeah.

RichieRichOverdrive wrote:

Threw up another old video in case it might be of any use to you. This was an excellent feeling clutch with a very linear slip-to-catch. Probably my favorite clutch I've built to date.

Thanks Richie! looks like a similar setup to whats already in my mower, I think I'll follow your examples to come up with something. The videos definitely helped me visualize what I'm actually looking at.

I think if I come up with some clutch system close to yours, then I could use the speed control lever as a handbrake for hillclimbing or whatever since the varidrive will be bypassed.

Any idea on the brake setup here?
I've got a silly hinge in there just to mock up a few things, and whenever I press the brake hard, it gets stuck, I even swapped out the spring for a stiffer one to help try and return the brake but no luck.

I adjusted the clutch rod so it engages the brake later when pressing the brake/clutch pedal but still she gets stuck.

It came with the disc brake and the KH400 caliper.

Anyone have pics of what they did for the brakes?
Or maybe y'all know a better way? (Am I missing parts maybe??)

Edit: I gotta skedaddle to work, but just looked at the manual real quick, looks like it was attached via spring the brake/clutch pedal? That sounds odd??

I wouldn't be concerned until I've taken it all apart, cleaned it up and lubricated what needs to be (the rotor should float on the shaft and the moving parts of the caliper). The return spring is alreadly there on the right side and it's huge, looks like it should be fairly simple to rig the handle up as a hand brake too which is a bonus!

Brianator wrote:

I wouldn't be concerned until I've taken it all apart, cleaned it up and lubricated what needs to be (the rotor should float on the shaft). The return spring is alreadly there on the right side and it's huge, looks like it should be fairly simple to rig the handle up as a hand brake too which is a bonus!

Yeah I think I should be able to have it act as a handbrake, that would be sweet
I've already taken apart and cleaned the caliper pads and the rotor does float on the shaft nice and free. Everything else though is a smidge stiff, wd40 helps but I agree definitely needs to be gone though again.

That spring isn't supposed to go there, but I think I'll keep that bigger spring on the brake setup anyway.

The one I had worked on had a similar issue until I had rebuild and readjusted everything after it was all hooked up, I even added a return spring to the caliper lever which may or may have not been done at the factory. That bolt with the jamb but on the outside allows you to adjust when and how hard the brake applies, if you haven't already that should all the taken apart and greased.

Brianator wrote:

The one I had worked on had a similar issue until I had rebuild and readjusted everything after it was all hooked up, I even added a return spring to the caliper lever which may or may have not been done at the factory. That bolt with the jamb but on the outside allows you to adjust when and how hard the brake applies, if you haven't already that should all the taken apart and greased.

Ahh I see you have a spring on yours as well! The return spring is a good idea, I think I'll see if I can put on on the caliper in addition to the big one up top.

I have played with the jamb nut, but I don't think I have it quite set right, I have it a bit extra tight right now to try and see if it helps prevent the brake from getting stuck being pressed down all the way. I'll play with it this weekend for sure

Budgie originally came with a clutch brake. You can see here I just cut the little lever plate off and swapped the clutch pedal shaft end-for-end so i could have a left foot clutch. The slot in the plate there hosted the brake rod.


larger version for context


ok so red arrow is the bottom side of my clutch lever. yellow arrow is the spring that attaches (seemingly) directly to the caliper, and between the spring and the lever is what's left of the original brake rod, that followed the path of the yellow line, up to the clutch pedal.  


The brake lever here was stock but I added a bit onto it for more leverage. You can see the little plate i added for a parking brake lol.


I always intended to remove the spring from the brake setup but never did. Sort of limited braking power. I don't remember if there was a return spring at the caliper. Seems like there was. Make sure to take your caliper apart and clean it when you get it, the pin in them tends to rust up and stick.

If i had known these machines would prove to be so popular I would have taken more pictures! An MTD with a 2300 was unheard of back then!

You definitely want to start with the brake loose and barely working then slowly adjust it until it's how you want it but until it's driving under power you can't really...

That pic is from when I installed a 2300 in a vertical shaft engined Craftsman DGT6000 which never came with one so everything you see there is custom.

RichieRichOverdrive wrote:

Budgie originally came with a clutch brake. You can see here I just cut the little lever plate off and swapped the clutch pedal shaft end-for-end so i could have a left foot clutch. The slot in the plate there hosted the brake rod.


larger version for context


ok so red arrow is the bottom side of my clutch lever. yellow arrow is the spring that attaches (seemingly) directly to the caliper, and between the spring and the lever is what's left of the original brake rod, that followed the path of the yellow line, up to the clutch pedal.  


The brake lever here was stock but I added a bit onto it for more leverage. You can see the little plate i added for a parking brake lol.


I always intended to remove the spring from the brake setup but never did. Sort of limited braking power. I don't remember if there was a return spring at the caliper. Seems like there was. Make sure to take your caliper apart and clean it when you get it, the pin in them tends to rust up and stick.

If i had known these machines would prove to be so popular I would have taken more pictures! An MTD with a 2300 was unheard of back then!

Thanks for the pics! I like the end-to-end rod idea, will probably swap to that later on. For now I'll keep it stockish to get it going for now

Brianator wrote:

You definitely want to start with the brake loose and barely working then slowly adjust it until it's how you want it but until it's driving under power you can't really...

That pic is from when I installed a 2300 in a vertical shaft engined Craftsman DGT6000 which never came with one so everything you see there is custom.

Yeah fair point, I'm going to work on the clutch system this weekend, not sure if I should use the varidrive shaft somewhat or just run a long belt from engine to trans. Seems simpler with a long belt?

Would definitely not use the VariDrive pulley but you may potentially need to add an idler in there somewhere, maybe not though.

Brianator wrote:

Would definitely not use the VariDrive pulley but you may potentially need to add an idler in there somewhere, maybe not though.

Well we will find out, I'll pickup a belt tomorrow and test fit it. I used an old extension cord to measure the length, came out to 95 1/4" long. Closest belt Princess Auto has is 96" so I'll try that. They have a 97" if I find it's too tight or something.

Brianator wrote:

Would definitely not use the VariDrive pulley but you may potentially need to add an idler in there somewhere, maybe not though.

Could maybe lock the variator to one side and use it as a single pulley for the clutch, similar to what I did with my jackshaft. As for idlers I do know that I had to add one to pick the belt up off of the steering shaft and another on the top side to raise the belt in the same place so it didn’t touch itself. I think I wound up with 3 idlers plus the jackshaft for the whole setup.

RichieRichOverdrive wrote:

Brianator wrote:

Would definitely not use the VariDrive pulley but you may potentially need to add an idler in there somewhere, maybe not though.

Could maybe lock the variator to one side and use it as a single pulley for the clutch, similar to what I did with my jackshaft. As for idlers I do know that I had to add one to pick the belt up off of the steering shaft and another on the top side to raise the belt in the same place so it didn’t touch itself. I think I wound up with 3 idlers plus the jackshaft for the whole setup.

Not a bad idea, I tried the 96" belt, not long enough. 97.5 is just not quite enough slack, so I either buy the 100" belt and have a bunch of slack, or I move the motor back an inch and see if that's enough.

Otherwise belt alignment was good, I ran the engine with wheels in the air and the belt stayed in the pulleys quite nicely so that's a good start

You have a clutch setup already!?

Brianator wrote:

You have a clutch setup already!?

I wish! That's today's project if time allows. At least figure out the basics of it.
The 97.5" belt has some slack, but is just tight enough to still spin the transaxle.

I'll snap some pics in a minute

Thinking this is where the clutch will be. I planning on stealing the old PTO idler by the motor and putting that where the lower V groove pulley is currently in the pic below.

Without actually being able to feel around and see it's hard to advise BUT it looks like you're on the right track, you already have a double pulley clutch thingie there. It looks like if you got rid of the VariDrive pulley that there'd be enough room for that to swing clockwise to engage the belt and it should put the linkage point at the right spot to connect a rod from the pedal. Keep in mind you need enough slack in the belt that the wheels won't engage when the tractor is on the ground and the clutch is disengaged, it's hard to try and size a belt without a functional clutch setup and belt guides installed (the have a braking effect and keep the slack where you want it).

I know tomorrow is Christmas but I'll be down your way to visit my parents and could make time to swing by for a little bit if you'd like?

Brianator wrote:

Without actually being able to feel around and see it's hard to advise BUT it looks like you're on the right track, you already have a double pulley clutch thingie there. It looks like if you got rid of the VariDrive pulley that there'd be enough room for that to swing clockwise to engage the belt and it should put the linkage point at the right spot to connect a rod from the pedal. Keep in mind you need enough slack in the belt that the wheels won't engage when the tractor is on the ground and the clutch is disengaged, it's hard to try and size a belt without a functional clutch setup and belt guides installed (the have a braking effect and keep the slack where you want it).

I know tomorrow is Christmas but I'll be down your way to visit my parents and could make time to swing by for a little bit if you'd like?

Yeah that varidrive has to go, moving the motor back 1 inch gives me enough slack to completely remove the belt from the pulleys with ease so that's got to be enough!

That would be sweet if you can come by, but I don't think I'll be in the garage at all tomorrow, girlfriend would kill me plus we got a crammed house this year    some time in the new year or spring would work better I think if that works for you!

No worries, I couldn't have stayed long anyhow. I'll let you know next time I'll be down that way.

Brianator wrote:

No worries, I couldn't have stayed long anyhow. I'll let you know next time I'll be down that way.

Works for me man!
If things work out maybe I'll be able to bring the tractor out your way and we can go for a ride