G16 low speed - limit secondary opening idea?

[Canuck12345]

I am once again about to modify another G16 that will only ever be used at the lowest possible speed.

With appreciation I have received some great ideas in the past from the more knowledgeable cart guys here on the forum, such as cut secondaries, heavier springs etc. They have all done a good job at giving more low end torque and at reducing the cart speed, but I am still searching for more ideas that would completely stop the cart from accelerating to higher speeds.

To be clear, the cart will only ever be used to climb/descend steep (ish) hills with a 300-400lb load on board. From experience the value of having the clutch engaged going downhill (thus providing engine breaking), is equally as important.
Going downhill we ride the brake at the same time as the throttle to engage the clutches, this helps with run away coasting. It is going downhill that the cart wants to shift up and goes too fast for the terrain.

My latest idea (which might be crazy??), is to modify the secondary clutch so that it cannot open at all.

If the idea isn't going to cause major clutch/belt problems, I was hoping to get suggestions on how to best go about preventing the secondary from opening.

Thought about welding a ring around the inside of the sheaves low enough in the sheaves such that the belt will not contact it, but not sure that the heat from welding might make the sheaves brittle???

Also thought about simply bolting through both sheaves, but was worried they won't hold given the rotational forces.

Thought about a combo of stitch welds and bolts??

Lastly, could the spring be removed and the shaft filled with spacers?

Would anyone know why this wouldn't work and have any suggestions on how to lock the sheaves from opening?

Thanks

[Gearhead1956]

LOL,
Now that's just the opposite of what every one here is trying to accomplish. Don't know if you will find anyone with real life experience on that. But some thought on what may work, reverse engineering.

Just my first thought.
The secondary clutch only reacts to the movement of the primary. So I am thinking if you limit the movement of the primary would keep it in a lower gear. Thinking you could just pull the primary apart and put a sleeve over where the belt rides to keep the two halves from coming together as much.
Also using a little longer belt would keep the engine rpm's a little higher for more HP at a lower speed. I think

[Canuck12345]

Yes I am kinda backwards on this.

I plan to have the heaviest primary spring I can get to keep the rpm up and the belt low in the primary.
I was thinking a fresh wide & tight belt would keep me in the power range.

From the other two carts I have already done and used, it seems any movement from the secondary increases speed more than we are wanting.
Unfortunately we have to lift the carts and increase the tire size to clear the rocks, the larger tires change the ratio in the wrong direction for us.

Maybe limiting the primary is the way to go which might require me to fab up some custom ramps with stops in them. If so now I am wondering if the power of the engine could cause the primary to fail?

It could said we are trying to make more of an off road rock crawler than anything else.

[Gearhead1956]

(I was thinking a fresh wide & tight belt would keep me in the power range.)

Thinking a wider tight belt will engage at a lower ratio but also at an engine rpm so low you would not be in the power band?

A 2 stroke sled engine with stock clutch and rear end gears!! My friend has one like that and all it has is low end! But it still does about 20 mph

[sho305]

I would try a cut sheave with a umax spring, preload more than stock. I would pop the primary and make a sleeve or bushing or spacer to limit how much it closes, you will have to experiment with this. I would set the factory speed governor low as you want, you still get full power under that speed. Far as engine braking I just don't think it would give you much even if you did get it to stay in gear, its a 10hp engine. I would look at disk brakes or better yet front brakes.

You might run up to a 1.25 belt but have to be careful they do not always engage properly. A longer belt usually hurts low speed performance, a shorter belt can help a little but basically does the same thing as a wider belt. You need to be careful because changing the belt size can cause you to not reach the lowest gear ratio. With a cut sheave you might be able to run longer belt but doubt it is that much difference, unless cut sheave makes the belt tight on the clutches. If the clutches are worn a slightly wider belt can work better.

The cut sheave is the only thing that will give you a lower (higher number) ratio I know of, aside from gear changes, and you need the belt lowest in primary that does not engage and half out of the secondary to get it. Make sure the tension cable is working if it has one. *Remember a wider belt goes higher in the secondary=lower gear (that also what a cut sheave does) but too wide will drag on the primary and make the cart creep on the starter. Find the best fit.

[Canuck12345]

Thanks Sho305, I have done a fair bit of snowmobile clutching and get what you are saying.

I really like the idea of a bushing inside the primary to limit the closing as this will not be effected by the rotational forces.

I will be looking around now for a heavy primary spring to keep the rpm up and a new secondary spring wound up tighter than stock to reduce the opening.

Thanks everyone!

[sho305]

I ran the kevlar belt from CPP, it was 1.25 wide best I could tell. It worked like a charm on my G9 clutches and with a cut sheave and umax spring. Put a clone in and still ran that setup with success. I put a 94c primary on because I could not get more rpm from the modded G9 clutch and it dragged in the belt. It would not engage right. I could not move the engine enough it hits the trans nearly and the gen is on front of it. So had to get a normal cart belt 1 3/16, a normal gboost not the kevlar. It works good now but still trying to figure out how to get the kevlar back on. Its a really nice belt that did not wear, double cog, I would recommend it if you need it. I guess my 94c is more picky about belts, is also new with no wear on it.