MPT 1200, Cruise Speed - Larger Wheels or Cluthes? To Lift or not to lift?

[Tfastle@aol.com]

Last fall I got an MPT1200 (350 MCI) with the engine blown up, apart and in a box, seats covers shredded from exposure, and tires flat. With the help of members of this forum I was able to get the engine cleaned up, parts ordered and it put back together. I have about a tank of gas through it and it seems to be running well so that is good. It accelerates very nicely, seems to have very good torque and goes up hills with no problem. The only thing is, it's natural cruising speed is a bit slow. By natural cruising speed I mean that point where a vehicle seems to cruise comfortably without having to work hard, labor or over rev. I understand that is a "feel" thing and everyone probably "feels" it a little differently but I would guess most people that have driven a lot of different vehicles understands what I mean. When I take off it pulls very nicely and as the engine revs to a point that feels, RPM wise, like it would be a good cruising speed we are only going 9-10 miles per hour. It will go faster but it feels to me like you are working it a bit to do that and I wouldn't want to run it like that for a long drive. If I push it, it will go about 15 mph and doesn't seem to hit the rev limiter in the ignition but that's about where it hits the rev limiter in my head so I back off.

I would guess, in the case of this MPT 1200 (and I assume all of them), that it's because this rig is designed to be more of a, as it's other name would suggest, Workhorse and was designed to drive and pull more like a tractor than a sedan.

We plan to use this at our lake house to tool around, run back and forth and just have fun on as opposed to do a lot of work with it. (I actually think I will end up making it so I can remove the bed and put another seat on the back.)

So, I am wondering if I am correct about these rigs - are they in stock from really not what you would call "cruise around" rigs and more work oriented? It seems to me if I were to put larger wheels on it then it's natural cruising speed would go up but I would sacrifice some torque. I am sure there is a happy medium that makes sense. Those of you that have done this, what size tires would you recommend? It looks to me like I could put some 20" tires on it without having to lift it. Does that sound correct? My concern with that is that 20" tires probably won't make much of a difference, or would they? If I go over 20" I am guessing I would need to lift it. Which would be fine if it's the best way to go and allows for me to address my concern. What I don't want to do is overdo it and end up with a rig that looks cool but is completely gutless because it struggles to overcome the inertia of the wheels that are too big.

Or, are the clutch(es) the best way to address this? I am guessing it could be addressed via the cluth(es) but is probably better via the wheels/tires. Anyone have thoughts on that.

While I do want it to look decent I am not overly worried on the looks front. Clean look is good by me. Nor am I looking for it to be a racer - just run nice, relatively strong and be dependable.

Any thoughts, advice and input, especially from those who have done some of these things to MPTs, would be greatly appreciated. If Trig123, JponLKN or Cartmaster happen to see this would love to hear your thoughts! You all have been a great deal of help on this project so far and, I believe, are familiar with these MPTs.

Thanks to all!

[trig123]

I own two MPT 1200's. Actually one is a Refresher Cart but its the same as the MPT 1200. Its my low rider.

These MPT carts should have the 11 hp engine with 28 degree driven clutch.

The TXT's normally have the 9 hp engine with 36 degree driven clutch.

One of mine has the stock wheels and tires. Of course it pulls a hill better than the other one which is lifted 4 inches with 22 x 11 x 10 wheels and tires on it.

The none lifted one don't have the top end speed but it walks up a hill much better than the lifted one.

I can tell you look wise the lifted one is much better looking. You can see for yourself which looks better. That is my shop cart .

I rebuilt both driven 28 degree clutches. One needed a new center piece in clutch. I installed new ramp buttons on both.

Lift that thing and put you some nice wheels and tires on it. I recommend the 4 inch lift and of course mine has the larger 22x11x10 tires on it. If your driven clutch is good it should pull a hill fine unless you overload it.

I also have a TXT that is part MPT 1200 It also will walk up a hill with just me and my dog in it This is one I plan on giving to my granddaughter maybe this year.

My 2 cents

[JPonLKN]

Well, I guess first of all, they are designed to run around 15 MPH, and they are designed to run up to a point where the governor on the transaxle takes over and pushes the throttle closed a little to a point where it maintains that speed. Entirely normal and what it is supposed to do. I am guessing you found the technical manual...there is a section in there that discusses how to go about setting that. To begin with, download a GPS speedometer on your phone if you haven't already, turn it on, and run it while driving the cart. You should floor the cart and let it accelerate to top speed. If its getting over 15 and the governor on the transaxle isn't pulling the throttle back, you need to adjust the governor. For testing purposes and for short durations...you can't hurt the motor, as the ignitor has a rev limiter that kills ignition/spark...you can't over rev it. I wouldn't run it there for long term, but for testing purposes, it won't hurt the motor if you happen to get up to that speed. Before we go further...you should do that to make sure there is a problem. My mom is an old lady, and she doesn't like running her car at highway speed for fear of blowing up the motor. We need to take "Feel" out of it.
Now, it is possible that your driven clutch isn't shifting...
since you are running and driving it, I'll assume the drive clutch is closing and engaging the clutch properly, but the driven clutch operates based on "realized load". It should start with the belt flush to the outside perimeter, and as you accelerate, the clutch spreads apart and allows the belt to ride further down, shifting the drive train. It is called a CVT, or Constantly Variable Transmission. As one clutch opens, the other closes, and vice versa. If you are starting with the belt at the top edge of the driven clutch and it doesn't open, you will rev up, have a ton of torque, but no speed. All the ones I have experienced started where they should, opened up on speed, but wouldn't upshift or close as I would approach a hill, basically keeping it in high gear when it should down shift. I took one apart and the button screws were all broken. Maybe Trig, Cart, or CP will chime in on your situation, but I have never seen one "stuck" and not open up. I've driven several and they only really seem like they are screaming as you approach 20 mph. 21 is about max before the ignition rev limiter in the ignitor kicks in and shuts down spark. I didn't have a tach on them, so I don't know what RPM that happens at. I would guess between 3500 and 4000.

If you have a workhorse, your driven clutch will be a 28 degree unit and not a 36 degree one. It provides more torque. The 36 degree units are provided on TXTs. As the diameters are the same, overall top speed for Workhorses and TXTs are the same. The difference is the rate of change of the belt diameter for a given "experienced load" on the drive clutch. The 1200 in the MPT name refers to the weight capacity for the machine. It is designed to haul quite a bit. If 15 isn't fast enough for you, upping to 20in tires will get you a few more MPH for the same RPM. Going to 22" or 23" tires should be just fine, but I haven't done it. I think Cartmaster has, but I think he is running the 295 head on his 350. I'll let others chime in on tire size and usability as mine are all 18" so far. My next task on my 1200 is to mount my lift and 23" tires, so I will be able to answer after that, but haven't done it yet.

[trig123]

JPonLKN, I have had a driven clutch stick. The cart hit the rev limiter quick, almost like it was starving for gas.

I was told at a service school 20 years ago that these engines shut off at 3750 rpm's. I am sure that is close.

There was one year these carts didn't have the rev limiter built in ignitor, I think first year they came out. I am sure they figured out pretty quick that part was needed.

[Tfastle@aol.com]

Thanks for the replies. I probably didn't phrase it well in my original post. I don't think anything is necessarily wrong, I would just like a less torque feel and a more cruise feel. I do understand how the clutches work and they look and seem to be working fine. When I ran it hard it did go right up to 15 and did not hit the rev limiter. If it had another 1-2 mph per hour don't know, I didn't floor it try. But I can and likely will to see. I guess I am more looking for the best way for it to cruise at a bit of a higher speed. I don't mean I want massive top end speed, but on a flat being able to cruise at 15mph without the engine having to work as hard (about like it's working at 10mph now). I suspect my best bet is to go with larger wheels, probably 22 or 23" as trig has suggested.
For those that have done that, do they still pull relatively well. I don't mean pulling a boat up a ramp but take off and navigate moderate hills ok?
If I do lift it 4" or so what is the best kind of kit, spindle or other and why?
Thanks!

[trig123]

Originally Posted by Tfastle@aol.com

Thanks for the replies. I probably didn't phrase it well in my original post. I don't think anything is necessarily wrong, I would just like a less torque feel and a more cruise feel. I do understand how the clutches work and they look and seem to be working fine. When I ran it hard it did go right up to 15 and did not hit the rev limiter. If it had another 1-2 mph per hour don't know, I didn't floor it try. But I can and likely will to see. I guess I am more looking for the best way for it to cruise at a bit of a higher speed. I don't mean I want massive top end speed, but on a flat being able to cruise at 15mph without the engine having to work as hard (about like it's working at 10mph now). I suspect my best bet is to go with larger wheels, probably 22 or 23" as trig has suggested.
For those that have done that, do they still pull relatively well. I don't mean pulling a boat up a ramp but take off and navigate moderate hills ok?
If I do lift it 4" or so what is the best kind of kit, spindle or other and why?
Thanks!

I like the drop axle lift. 4 inch is enough for me . Just the right enough space between tires and body. My opinion only.
This pretty much explains things.
https://www.golfcarttiresupply.com/g...what-they-are/

[slonomo]

Mine does 19 mph with the governor cranked all the way. I backed it down to 16 mph. It seems super slow after driving my 670 powered G1 But 15 mph is faster than walking. Heck, I'm not sure I could run that fast, not for long anyway lol.

I think if you don't have any hills to climb, or trailers to tow, a TXT 36 degree driven clutch will give you the "cruise feel" you are after. I know what you're saying. On takeoff, the 28 degree clutch is a little touchy feeling, grabby like. It feels like it stays in "low gear" way too long. But again, these were made for working so...

[Tfastle@aol.com]

Sorry for the slow reply, had to leave town for a few days.

Thanks for the additional information and the link to the article about different methods of lifting. I have read sometimes when you lift a cart with a 4 stroke engine it changes the angle at which the engine sits and you have to run a lower level of oil. Is that always the case or more model specific and how much you lift it? On an MPT would you run into that and if so, at what level of lift. Although, I would agree that 4" looks like a good amount.

On the driven clutch, what does the angle refer to? Angle of what? I gather it's something internal, maybe ramps, and it's not the sheaves - and with the 28 degree the lesser angle the less rapidly (maybe because it requires greater centrifugal force) it allows the belt to move to the inside or center of the driven clutch? Has anyone here done that, put a 28 degree driven clutch on an MPT? Did it lessen torque but increase speed? Might be a good way to go.

[slonomo]

Originally Posted by Tfastle@aol.com

Sorry for the slow reply, had to leave town for a few days.

Thanks for the additional information and the link to the article about different methods of lifting. I have read sometimes when you lift a cart with a 4 stroke engine it changes the angle at which the engine sits and you have to run a lower level of oil. Is that always the case or more model specific and how much you lift it? On an MPT would you run into that and if so, at what level of lift. Although, I would agree that 4" looks like a good amount.

On the driven clutch, what does the angle refer to? Angle of what? I gather it's something internal, maybe ramps, and it's not the sheaves - and with the 28 degree the lesser angle the less rapidly (maybe because it requires greater centrifugal force) it allows the belt to move to the inside or center of the driven clutch? Has anyone here done that, put a 28 degree driven clutch on an MPT? Did it lessen torque but increase speed? Might be a good way to go.

Yeah, too much angle and you could change the way the oil is distributed in the crankcase. Oil starvation is the risk.

The 28 degree vs 36 degree I believe is the ramp angles.

[JPonLKN]

I would guess you have a 28 degree now. 36 degree is the TXT driven clutch. It is embossed on the outside of the clutch...peek around...you will see it.