36 vs 28 degree driven clutch EZGO/Clone

[jrv97240]

What is everyone running on their EZGOs with a 420 clone? I purchased a started project that included all the parts so I have a brand new 28 degree driven clutch on my cart. It obviously is causing me to run much higher RPMs before shifting out. Would I be better off going to a 36 degree with a clone? I drive 100% on pavement mostly cruising the neighborhood. I have 23" tires and a rear seat if that makes a difference.

[sho305]

I think it depends, with a yamaha the stock clone is perfect on stock clutches and runs great. Its just like stock power but twice as much. When I started modding my clone and needed more rpm I ran into problems. I modded the clutches and changed springs in the secondary (yamaha have no spring in primary) and drilled the weights in the primary. It worked then more mods and found I could not get it to do more. Finally I had to move to a different primary and found a 94c cheaper and got that. Its not the best but working fairly well. Of course then the secondary was all wrong and I had to change it all because of the new primary clutch. I had a stiffer umax spring in there and took it out, changed the preload to more than before. Did a bunch of setups on the 94c went to more spring but cut it shorter and forget what pucks it has now, but its close and will run any max rpm I want it to, about 4K right now. Its not as good when you go slow around the yard is the only real down side, it wants to rev. I have calmed it down now but still needs more tinkering. But the 94 is an old sled clutch and was never really designed to run this slow with a 2000-2500 engagement or so. At higher rpm its pretty good.

So I guess what I mean is it depends on what you plan to do with the engine and what clutches you will run.

Funny part is the 94c was for an ezgo.

[LostHusker]

You could always try the different settings on the clutch, the spring can be set to three different spots. The first spot is most common for most clutches, the middle one provides a little more torque, and I can only imagine the 3rd spot would provide even more torque. Now I have a 36 clutch but like what I get from the middle position of the clutch but still playing with that. I am running a vanguard but hopefully this will give you an idea...

[sho305]

Thing is the twins have tons of bottom end, so if the clutch shifts too soon or too low of rpm it is great with a twin. The clone needs to rev to over 3K at least to make good power, while the twin is making a lot at even 2K+. It you mod the clone which is easy and cheap to do, you need to let it rev more yet. I need to see 4K on the tach when I floor it or I don't get full power. A stock cam twin would be way past full power at 4K they don't rev like that. Everyone told me a variation of the stock ezgo setup I had in my 94 was the best and I could not get it to work, because I had a clone. The twin likes that setup but my clone with some mods needs to rev more. The stock clone I did likes 3600 no more than 3800 shift, and that is right where the stock yamaha clutches shift at WOT. It has no governor and an automotive airbox and muffler, otherwise all stock. The clone I run I have done a lot more stuff to and soon it will have new rod and cam.

The secondary spring if you can change the preload; tighter will give more rpm at low throttle and maybe little more WOT. It will me more zippy and quicker to respond when you gas it, it will rev more when going steady lower speeds. Less preload will make rpm drop when you let up on the gas, at steady speeds, going down hill, etc., but it will still rev to almost the same rpm WOT just may be more sluggish to rev as quick.

[LostHusker]

Originally Posted by sho305

Thing is the twins have tons of bottom end, so if the clutch shifts too soon or too low of rpm it is great with a twin. The clone needs to rev to over 3K at least to make full power, while the twin is making a lot at even 2K. It you mod the clone which is easy and cheap to do, you need to let it rev more yet. I need to see 4K on the tach when I floor it or I don't get full power. A stock cam twin would be way past full power at 4K they don't rev like that. Everyone told me a variation of the stock ezgo setup I had in my 94 was the best and I could not get it to work, because I had a clone. The twin likes that setup but my clone with some mods needs to rev more.

Great info,

[sho305]

I had a heck of a time with it, at the time everyone had used the 94 on twins not clones so nobody knew there was a difference. I have had the clutches off there minimum 20 times changing setup on them. Now my secondary spring that was new broke so have a new one to put in again, not sure why it broke.

Best I can tell you is get a tach even a $15 mower tach if you have to. Drive around and gas on it and feel when it pulls hardest, not the loudest, not high rpm, but when it pulls you in the seat. That rpm is the area you want to be in when it is shifting at WOT. With a CVT shift rpm is the rpm you see at full throttle until the clutch has shifted all the way, then its just a high gear more or less and you hear rpm start to climb. Most stock lawn or cart engines that will be maybe 3000-3800 rpm range. If it pulls harder when it hits full shift and revs more near top speed then its shifting too low. If it pulls hard out of the hole and then less when it revs, its too high. When I got close I set a run up to about 25+mph when it was just fully shifted and starting to rev more, I would run it and see what my rpm was. The higher it was the faster I was going in that set distance. Pain to manually figure this all out but hey it was fun to mash the gas all those times.... I set the clutch to run under 4K rpm and over and it was fastest right at 4K.... but that is just my combo.

If you had money you would just dyno the engine and then set your clutch to shift at peak power, engage at max torque or just under depending on how hard you want to launch.

See with a stock lawn engine or most 4 stroke cart engines they all run good HP and shift at 3600 or so, and so they all shift pretty well sort of. Soon as you go messing and modding things they don't necessarily work together anymore.

[jrv97240]

This is my 2nd clone. The first was a yamaha and I did some experimenting with the uMax spring, heavy torque spring, and the normal spring with various preloads. I ended up using the stock spring. The is my first EZGO though so was mainly just wanting to hear from people who have clones and the 28 and 36 degree clutches on what works best? If the 36 works fine I will probably go that route so I dont have to run so many RPM driving around in my neighborhood.

[jjastram]

What timing for a "Which Clutch to Use" thread. I just broke my driven clutch, this afternoon, trying to remove it. With a Vegas Carts 460 in my 2001 EZGO, should I replace it with the 28° clutch or 36° clutch? Vegas Carts say to use the stock clutch, but I'm not concerned about how fast it goes. So what would be the best one to use?

[sho305]

IIRC the 28 helps it rev more under load because the helix has more angle? You have to remember this is how the clutches react to torque. You shift rpm is set with the primary clutch and at full throttle. The secondary spring and helix (ramps) will change how it shifts some but mostly change how it shifts at light throttle compared to full throttle...or how it reacts to the engine torque. Either it reacts a lot and revs, or it does not and rpm stays the same when you mash the gas. So the secondary changes mostly rpm at light throttle and primary at full throttle, of course if you mess with one it can affect the other.

If you have a lot of rpm driving slow you need less preload in your secondary, or less spring (need a weaker or shorter spring). I have this issue with the 94c because it works differently than the G9 clutch on it before. Also make sure your belt is not too tight, I found the tight belt on the 94 makes it not want to shift. It shifts better once the sheave moves in a little. Conversely if you have stock power a tight belt can get you more rpm on take off and help you.

I took the umax out and found the stock (but new) spring worked better with this clutch but using more than stock preload. I think because the umax is stronger it puts pressure on it at rest and takeoff. The stock spring with more preload put more pressure on the ramps and less on the sheave, so it has less taking off but comes on more while it is shifting at speed.