UTV Question

Working on a 13 hp Honda engined, 2wd, single 2 person seat, American ....forget the next word of the brand name.....Trail Wagon. Question is
about the Continuously Variable Transmission connecting the engine to the differential/tranny.

Complaint was "seems to be slipping". Not a lot of hours on this adult driven machine,

I removed the covers and saw that the belt and the sheaves were slick so I cleaned them up. On the belt I took 220 grit and rubbed the glaze
off the sides and shot it with some belt dressing. Belt now looks new. Acceleration from ⅓ throttle is superb....hang on. Don't figure I have a
bad belt if I can do that now. While the covers were off I watched the drive clutch manipulate the drive sheaves from wide apart at idle to WOT
and it was all a seamless process.

If the idle rpms are set too high, you can't shift into gear. Slowing down to the recommended 1400 allows the drive clutch to back off the belt
and (with it flopping) the tranny can be shifted (FNR), and the engine NOW holds a good solid idle and accepts throttle; got that part all ironed
out.

So my thinking is that since the belt can't be in contact with the sheave sides at idle, it has to be loose......and here's the question: Therefore
when you accelerate, you have to wait for the sheave to close onto the belt providing enough tension for it to transmit power to the rears. If you
press down on the accelerator they close too fast and when making contact you get a good jerk. If you just touch the accelerator you have to
wait maybe 15 seconds for the belt to be picked up.

This makes for a sloppy, clumsy start. Once the vehicle is moving throttle movements up and down produce smooth responses.

Is this how they operate on this type machine?
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I have zero experience with these types of drives but after Wikipedia and several UTube demonstrations I am duly impressed with the design.
The designer was good at what he does and it certainly fits the application. Problem with all those examples, the applications were other types
of vehicles so I didn't know if the UTV system might be different. The ones I saw seemed to hold the belt tighter at idle, not loose on the drive
end which would make for a smoother take-up and start off.

Thanks for your time,
Mark

The belts on these things are very sensitive to wear. The width of the belt is critical to them working right. You really need to get the specs from the manufacturer and check the belt to be sure it is within spec. I had to change the belt on my kawasaki teryx because it wasn't acting right similar to what your describing, and I couldn't see anything wrong with the belt I took off. This is just my experience with them.

Same as a snowmobile. We have Polaris side by side and a Polaris 4 wheeler. Both act the same as you describe. Belt is loose on the primary clutch until proper engagement rpm is reached and then they grab. Have had snowmobiles my whole life up until two years ago. Different springs, ramps and rollers can be used to adjust engagement rpm and change shift characteristics. What you are describing seems normal for that type of transmission.

when we were getting our first UTV, that was the only thing relayed to us was if you buy one with a belt, have a new one on hand always!
i went with a honda with automatic tranny.

I have to ask....What is a UTV?

You need to check the side clearance between the driving sheave and the belt at idle. There is supposed to be only a certain amount of clearance, may tell you what it is in the operators manual. Too much and you have to rev it up before it engages the belt. Sounds like you have too much. Also do not use belt dressing on the belt.

I was going to add that when a belt gets glazed a lot of things can get screwed up. Keep one or two spare belts handy. Up in heavy snow country you got to be crazy if you don't carry that spare with you. Just a thought for you.

Similar to our Gators. Make sure they are idling at the right speed or you won't shift without grinding.
On one of ours it's a bit of a pain...slowly accelerate, nothing happens and then the slip clutch moves and it grabs. I cleaned it up and shot some spray teflon lube inside the clutch and it seems to engage much smoother.
Note : don't spray the sheaves where in contact with the belt.

That type system can be improved with an idler pulley that only slightly ingage's belt. The easiest to install,trickest for kids to operate and most dependiable is manually engaged after shifting into gear and disengaged when machine start's moveing. Trickest to install.easiest for kids to operate and requires tweaking time to time is engaged until break is pushed then re-engages when break is released. The principle of operation is to take up slop to slightly tighten belt until eccelerator is pressed after shifting into gear.

(quoted from post at 20:42:36 01/01/17) I have to ask....What is a UTV?

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Called a "Utility Vehicle" like a side by side machine.

I think the transmission you are talking about is used on my go-cart and UTV's. Someone told me it's also used on snowmobiles. I think it may be used in ATV's.

The width of the belt is critical for correct operation. My belts are made of Kevlar. If the pulleys are rusty, it will eat the sides of the belt.

The idle speed of my kaw 4010 mule is critical. 950-1050 rpms. Anything faster, you will grind gears shifting. I bought a good tack. It's a wire that goes around spark plug wire. A good tack takes the guess work when it come to setting the idle speed.

The colder it gets, the faster my engine idles for a few seconds on start up. The computer sees it's cold and speed up the engine. If I don't wait for it to slow down and jam it in gear, tires will spin and gears will grind.

I worked on a friends go-cart. He leaves his outside in the elements. Both his pulleys were solid rust, belt was gone. Good think his belt is only about $10. I keep a spare belt for my go-cart.

I have the same on my snowmobile and Mule. On all the snowmobiles that I have had the pulley on the trans. should have a little lube on the shaft. I use a dry lube and just give it a light sho. The clutch should be open at an idle and the torque converter will be shut. You can see the shaft while the machine is off on this pulley. The clutch never gets lube because it will get on the belt

I've had 4 wheelers and snowmobiles with that drive set-up for 25 years. As others have said, I would put a new belt on it and keep the old as a spare. Then make sure the clutch on the engine isn't sticking or the plastic guides (?) the rollers ride on don't have notches worn in them. At only 13 hp, you shouldn't be getting jerking out of that setup. My 100+ hp snowmobile was always smooth as silk from 0 to 115.

The secondary pulley should be in tight contact with the belt when the machine is at a stop because the secondary should have shifted back while coming to a stop. As others have said snowmobilers tune and adjust their secondaries to get the back shift just right, so that it is ready for a smooth reapplication of power. You want to also insure that the deflection or free play of the belt is correct. This is also adjusted on the secondary by shimming between the sheaves. The primary wants to be completely open while stopped, the the spring inside it makes it engage smoothly as you give it the gas to take off.

WOW!!!!!!!! GREAT JOB GUYS. THANKS. Now I'll sort through your handiwork.

1st reply working my way down and again, thanks to all.

At rest, the belt is even with the top of the sheave on the secondary pulley. Again, I do know that the switching of gear ratios from high torque
to high speed with both primary and secondary sheaves functioning, does occur. Sloppy primary connection. I'm where you indicated.

Belt is $110 + $6 shipping. Lady is of limited means and if I understand that what we have is what it's supposed to be and she accepts it then we will stay here. Otherwise she will be out the cost of the new belt. If I knew for sure the belt was bad enough to require replacing, I'd recommend it to her and maybe buy it for her. However, moving down the list and with how it performs other than the initial engagement, I think it's grabbing sheaves just fine. Thanks.

There is roughly a half inch gap between the rear of the belt and the drive shaft, horizontally, between the primary shaft and the belt at current idle position. Belt rests on itself and doesn't touch shaft. I assume you mean dry lubing the primary shaft to assist in the clutch driving the primary sheave against the belt. I'll do that and ensure that it doesn't get on the belt. Thanks.

Working through your comments:

1. I called the mfgr and had a super conversation with a very knowledgeable lady who was able to pull up this machine by serial number and give me the part number of the OEM belt. Looking that up I am assured I have the correct belt installed. It is 1.1" wide and has cooling fins on both sides. Edges show no signs of fabric deterioration, just were slick. I pulled up the belt to see if it was fabric wrapped (wanting to sand the sides if it wasn't) and it wasn't. The belt was cut from stock with the layers exposed. I see that Kevlar belts are available but don't know it this is reinforced with such or not. That was one of my initial questions: Has the belt stretched to the point where it should be almost touching the shaft when at idle or is this the length. Measurement solved that question.

2. The machine was suffering from sincere neglect and nonuse. Battery wasn't discharged, it was dead...1+ ohm across terminals. Total jam up of fuel system to the point where neither butterfly in the carb would move, the float was stuck and light yellow varnish was everywhere. First time I saw the effects of ethanol. I say that because I have been around engines long enough to see varnish caused by gasoline we had back when Tetrahethral (spelling) Lead was added to the gas. Engine oil was blacker than any diesel tractor I ever owned. Gas stunk. Had 3 soft tires, one flat due to a thorn puncture. Windshield was broken.

Got all those problems fixed and initially had a hard time keeping the engine running at a low enough rpm to shift without having to do as you said...jam it in gear......didn't want to do that as it didn't sound good and the accompanying lurch of the vehicle. Snake oil played a big role in moving from almost fixed to fixed on the engine idling properly. "Sea Foam" was the icing on the cake. I dumped a full can into 5 gallons of fresh gas and with a fresh oil change, cleaned up carb and fuel lines and a new battery, just ran the engine till it would idle smoothly. As I got the engine running correctly I could adjust the idle down to where I could shift with out crunching and idle properly.

3. No computer on this baby. Wants the choke full on, but once it lights off (immediately, no throttle, just choke) I can push the choke in and she idles. I let it run for a couple of minutes before shifting.

4. Pulleys on this machine seem to be aluminum and were polished with some belt friction shine/goo on the belt contact surfaces. I Chem tooled and steel wool cleaned the crud off them.

Thanks

Yes made for two persons side by side. Thanks

Yeah a manual control, like a clutch for the automatic clutch would help loads. Thanks,

(quoted from post at 07:21:06 01/02/17) There is roughly a half inch gap between the rear of the belt and the drive shaft, horizontally, between the primary shaft and the belt at current idle position. Belt rests on itself and doesn't touch shaft. I assume you mean dry lubing the primary shaft to assist in the clutch driving the primary sheave against the belt. I'll do that and ensure that it doesn't get on the belt. Thanks.

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Belts for my Snowmobile are over $200.00 at dealer but I get mine on line. Reading your description of the start again makes it sound like a weak spring in the primary. There are probably many options for that spring, to enable the kind of start that you want. Some snowmobilers put a very strong spring in there so that their sled will "launch" when the RPMs reach engagement. Before reinstalling either pulley on its shaft, by all means lubricate that shaft to facilitate next removal, but whatever you do don't get any lube other than graphite inside either pulley. Any oil or grease that you put in there will ultimately turn to glue when combined with belt dust.

"On one of ours it's a bit of a pain...slowly accelerate, nothing happens and then the slip clutch moves and it grabs." As I mentioned earlier, will dry lube shaft to assist primary sheave in smooth movement onto the belt. This may be the smoking gun I'm looking for.

I can surely understand the significance of your comment. This lady drives it around her 10 acres and goes about ? down a rock road to her son's house on occasion. Thanks

I downloaded the manuals for that machine and see no dimentions....would be nice if I had some. After I did use the dressing and got the belt nice and sticky, I realized what you said about no dressing so I deliberately pretty much wore it all off. Seems to be a fine line between the extremes of too slick and too tacky. Thanks

A JD "Gator" single seat 2wd type thing. Utility, covered, windshield equipped, all terrain vehicle with a pickup type tilting bed in the back........and seat belts! Grin. Thanks.

OKAYEEEE! Another great answer. I will however, go out this morning and lube up the primary shaft with dry lube just to have that done. Thanks

I'll check it again. Spec is 1.1". I really want to be sure if I ask her to pay for a new belt and considering her situation, will try to get her to accept the shaky start. Course, I don't know if it has always been that way since she acquired it used. Will ask her when I take it back and have her drive it. Thanks

While reading through the answers I formulated a course of action with regards to lubrication. I'll pop the belt and spray the primary shaft with
dry lube all around. Let it dry. Run the machine with the belt off to get the clutch to working and watch the movement of the sheave vs rpms.
Stop and do it again. Then clean the sheaves to remove any lube that may have gotten on them. Then reinstall the belt and see what happens.

I did check the belt availability online and it's running $100-110 for the OEM belt. I remember seeing the Kevlar material in something I read
while looking but don't remember if it's one of those belts that meet OEM specs. Thanks again

Ok folks. You really came through for me. Hope I can repay the effort to somebody in need down the road on something pertinent to them.

Thanks again,
Mark

(quoted from post at 08:48:05 01/02/17) While reading through the answers I formulated a course of action with regards to lubrication. I'll pop the belt and spray the primary shaft with
dry lube all around. Let it dry. Run the machine with the belt off to get the clutch to working and watch the movement of the sheave vs rpms.
Stop and do it again. Then clean the sheaves to remove any lube that may have gotten on them. Then reinstall the belt and see what happens.

I did check the belt availability online and it's running $100-110 for the OEM belt. I remember seeing the Kevlar material in something I read
while looking but don't remember if it's one of those belts that meet OEM specs. Thanks again

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Since it is what my owners manual for my sled says, I will pass on to not rev it very high with the belt off.

(quoted from post at 20:42:36 01/01/17) I have to ask....What is a UTV?

Click to expand...

Utility Task Vehicle