1980 MTD 918 - 'Ol Rusty!

Rustbucket Garage wrote:

Brianator wrote:

I've never seen it done like that before, with that said... good stuff!

As for motors... avoid Tecumseh Snow Kings from snowblowers, I know they can easily be found and for cheap but there's a reason for that, they like to snap the connecting rods even at stock engine speeds!

Little off topic, it’s been a while since I’ve watched an autopsy on one of those snow kings but all the ones I’ve seen were a result of low oil. Don’t seem to be a necessarily bad motor, considering they made them for around 30 years I’d say they’re pretty decent.

I almost wonder if it’s because people are late for work, need the driveway cleared, in a hurry, aren’t checking the oil and running it till it dies. JMHO though, sounds like you’ve got the voice of experience talking!

Anything’s better than those stupid Briggs singles that puke rods and compression releases! Lol.

Well if they aren't too bad, maybe I'll snag one because I realized now, the Kohler I was set to get is a vertical shaft, and this tractor used to have a horizontal shaft motor....

Unless it's not that bad to modify the pulley and clutch setups to work with vertical?
The transaxle has the input shaft on the side though so I'd have to twist the belt if I go vertical...

The toughest part I found about building a twisted belt system from scratch was the clutch, that was quite tricky. The Kohler could be converted to horizontal shaft with a oil pickup tube and a different carb intake, I think that's all it takes to be honest.

Keep your eye on Kijiji for a Honda clone, good deals pop up every now and again

Silver_Pharaoh wrote:

Well if they aren't too bad, maybe I'll snag one because I realized now, the Kohler I was set to get is a vertical shaft, and this tractor used to have a horizontal shaft motor....

Yeh, the tecumseh would be my recommended path, they are also generally really cheap.

Brianator wrote:

The toughest part I found about building a twisted belt system from scratch was the clutch, that was quite tricky. The Kohler could be converted to horizontal shaft with a oil pickup tube and a different carb intake, I think that's all it takes to be honest.

Keep your eye on Kijiji for a Honda clone, good deals pop up every now and again

Yeah I keep checking just in case!

PizzaKitty26 wrote:

Silver_Pharaoh wrote:

Well if they aren't too bad, maybe I'll snag one because I realized now, the Kohler I was set to get is a vertical shaft, and this tractor used to have a horizontal shaft motor....

Yeh, the tecumseh would be my recommended path, they are also generally really cheap.

What do you guys recommend for HP? Stock was 16HP, is there a minimum where you guys find these tractors just dont have enough ummph?

It's a bit dependent on the size and weight of the tractor plus rider AND the actual make and age of an engine as well... older cast iron 10hp Briggs, Tecs and Kohlers actually have alot more power behind them than most people would realize, definitely more than enough to get you into trouble turning bigger tires with a mild pulley swap! Lol. With that said, overall 12-14hp is the sweet spot in my opinion and anything above that I don't think is required for what were doing because we're never going to use it.

I agree with @Brianator except my sweet spot is 15-18 but my tractors are pretty heavy.

I've seen where some dudes made due with 212cc.  (6.5hp)

MightyRaze wrote:

I've seen where some dudes made due with 212cc.  (6.5hp)

Yes, if you gear it right, I think about 30 kph is about the limit, a Tecumseh snow blower engine will be about 8 hp

Brianator wrote:

It's a bit dependent on the size and weight of the tractor plus rider AND the actual make and age of an engine as well... older cast iron 10hp Briggs, Tecs and Kohlers actually have alot more power behind them than most people would realize, definitely more than enough to get you into trouble turning bigger tires with a mild pulley swap! Lol. With that said, overall 12-14hp is the sweet spot in my opinion and anything above that I don't think is required for what were doing because we're never going to use it.

MightyRaze wrote:

I agree with @Brianator except my sweet spot is 15-18 but my tractors are pretty heavy.

I've seen where some dudes made due with 212cc.  (6.5hp)

PizzaKitty26 wrote:

MightyRaze wrote:

I've seen where some dudes made due with 212cc.  (6.5hp)

Yes, if you gear it right, I think about 30 kph is about the limit, a Tecumseh snow blower engine will be about 8 hp

Well the 2300 weighs probably 50LBS, I've takes some things off the tractor like the deck mount and there some parts from the PTO left on it, but the guys if the PTO were already removed when I got the mower. Plus I'm a heavy guy so I'll lean towards the 14HP side of things probably lol.


Speaking of pulley swaps, looks like the 2300 has a 6.5" pulley on it. What do you guys think should be the pulley on the motor? I don't want to overspeed the 2300 by an insane amount but a bit extra would be nice to have I think?

I've run a 4 inch on the trans and 7 inch on the engine with a 2300.  Just don't get it wet.  It will slip like crazy. LOL

I am currently running 5 inch on Trans and 7 on the engine with my tractor Dirty Rat.  I get decent speed.  No land speed records.  

My friends tractor has a 2300 with a 6.5" trans pulley, with a 6.5" on the engine and 25" tires out back he can get up to about 12mph which is enough to feel a breeze and fling mud out of the tires. A 8" would probably get it close to 15mph and a 10" to 17-18mph all this assuming 3600-3800rpms. I've heard that the 2300 doesn't take to being oversped too much but I'm not sure why, I've seen the guts and they look good and are oil filled. I'd make sure to add a vent if it doesn't have one (some come with them and others don't) so pressure can't build up in the case.

MightyRaze wrote:

I've run a 4 inch on the trans and 7 inch on the engine with a 2300.  Just don't get it wet.  It will slip like crazy. LOL

I am currently running 5 inch on Trans and 7 on the engine with my tractor Dirty Rat.  I get decent speed.  No land speed records.  

Brianator wrote:

My friends tractor has a 2300 with a 6.5" trans pulley, with a 6.5" on the engine and 25" tires out back he can up to about 12mph which is enough to feel a breeze and fling mud out of the tires. A 8" would probably get it close to 15mph and a 10" to 17-18mph all this assuming 3600-3800rpms. I've heard that the 2300 doesn't take to being oversped too much but I not sure why, I've seen the guts and they look good and are oil filled. I'd make sure to add a vent if it doesn't have one (some come with them and others don't) so pressure can't build up in the case.

Yeah I was hoping and thinking about 30Km/hr top speed, which would be attainable with the 4" and 7" pulley setup MightyRaze had tried. But that would put the input RPM at around 6300, almost double what the 2300 is recommended to have... Has anyone tried that long term??

Not personally no, my Massey Ferguson is hitting 15mph but is only at the start of it's journey and my friend doesn't have much seat time on his rig yet. A different friend has been running his 633a hard for over a year without any issues and he's getting up to 27mph!

Brianator wrote:

Not personally no, my Massey Ferguson is hitting 15mph but is only at the start of it's journey and my friend doesn't have much seat time on his rig yet. A different friend has been running his 633a hard for over a year without any issues and he's getting up to 27mph!

I guess it all depends on how you treat the transaxle too and it's condition?
Mine had zero water in it when I drained it, just thick black gear oil which I swapped out. I'm hoping that means the bearings are in good shape.

I was looking back I think I had a 6.5 engine, 4 inch trans (that i know).  I was hitting like 19mph but not sure of engine RPM.  I'd guess about 3800-4k with 25's on the rear.  Most people's carnage are from bouncing them (transaxle) off rocks, clutch dumps, gear grinding.  Keep your seals good and keep oil in it.  Water out. It should last.

MightyRaze wrote:

I was looking back I think I had a 6.5 engine, 4 inch trans (that i know).  I was hitting like 19mph but not sure of engine RPM.  I'd guess about 3800-4k with 25's on the rear.  Most people's carnage are from bouncing them (transaxle) off rocks, clutch dumps, gear grinding.  Keep your seals good and keep oil in it.  Water out. It should last.

Yeah I kinda figured they were being abused, I've seen the insides of the 2300 online, looks strong and well built.


For motors, I have a line of a brand new 15HP Princess Auto horizontal, and I found an older version Honda GX340, both a similar price. What's your guys opinion? I don't know which way to turn. I know the Hondas are great, but the 15HP is brand new....

To me it would depend on the overall condition of the Honda, if it starts easily, runs really well and has good compression I'd choose it because well, it's a Honda! Lol.

That's a toughie but I'd definitely investigate the Honda if it's a fair price.

If me, I'd probably get the new one.  You don't know the use and abuse the 340 had.  Plus maybe some kind of warranty on the new one?

Brianator wrote:

To me it would depend on the overall condition of the Honda, if it starts easily, runs really well and has good compression I'd choose it because well, it's a Honda! Lol.

That's a toughie but I'd definitely investigate the Honda if it's a fair price.

I'll dig into it more and see whats what!

MightyRaze wrote:

If me, I'd probably get the new one.  You don't know the use and abuse the 340 had.  Plus maybe some kind of warranty on the new one?

Probably no warranty, not sure when the seller bought the new motor.
Fair point on the Honda, looks like something was bolted to it, I'll see if I can find out what life it uses to have.

Motor acquired!

I had a weird shift today so I had a chance to visit my dad's and help him out with a tree and his tractor tire, in return he gave me this Honda GX390 complete with battery and electric start!

We did a compression test and it had 150 in it after all these years sitting

That's awesome man congrats!

Yeah can't wait to start it up! Gonna wash my summer rims tomorrow before I store them so I'll powerwash the Honda too then check it over and test it out.

Need to make a mount plate for it, find some pulleys and a few other things.
Hoping to have it running under it's own power before we get lots of snow that way I can test it out on some snowhills

Got it running! Vid link below,

https://drive.google.com/file/d/17DBmzNK5y8LvFgXa8Ay-kBSv_oxSiWq8/view?usp=drivesdk

Needed the valves adjusted to run. Before adjustment I was barely able to turn it over and the electric start could barely get it going. The exhaust valve was completely loose so the automatic compression release wasn't working.

Rather than try to locate a voltage regulator that is compatible with the bolt in charge coil, I'm going to use a new delco-remy alternator that was lying around here. It's a 3 wire and I've watched enough videos now so I think it'll do good once I hook it up. Gonna focus on that later though, for now I need to mount the motor and get the original fuel tank reinstalled on the tractor.

I'm gonna leave the Honda fuel tank on as a "reserve" tank for long treks or whatever. Anyone used an electric fuel pump on these tractors? I saw a few 2.5-4psi versions that might work if I put a tee inline after the pump and route the other hose back to the tank to avoid overfueling the carb.

Sweet little honda! Funny, the only 390 I've been around was in my shop because it needed the valves adjusted. That thing would about pull your arm out of socket before I fixed it! The delco alternator should be a nice addition, I had one in budgie for a while but never really used it- the 6hp didnt need a battery and the 18hp had it's own charging system. As for the electric pumps, it really depends on the carb. I've seen them work with some and some it floods out like crazy. Doc Sprocket did say that a good carb should hold back 5psi of air when you turned it upside down.

Someone told me once that it was a common thing to put a big harley carb on a suzuki samurai back in the day, but the stock fuel pump would overpressure them something fierce. They would add a return line after the pump with some sort of fuel filter in the return line. The filter in the fuel line would add just enough resistance to keep fuel in the carb, but not so much to where it would overpressure it. You might try something like that.

In the mean time, if your charging is 6amp or less on that engine. I've seen some guys use these on clone engines.
Kohler 233959 | Diode, 6 Amp Harness

I've thought about electric pumps too but don't like the idea off adding electronics unnecessarily especially when the Briggs style pulse pumps are so cheap plus they're easy to swap out on the trail if needed. An electric pump has no reference to demand so it will try to pump the same regardless of engine rpm, they might work great though so maybe you could be the test horse to find out!