Clutch And Gearing Adjustments
 

Everything is peachy a year after swapping the VC625 into a 1996 TXT. The 780R clutch and 8:1 gears give the desired top speed. At low speeds like pulling wheeled garbage cans to the road it runs about 2,000 rpm which is OK. But driving like that and picking through tight spots I would like to have a bit more throttle control via a higher rpm. Also, I can't spin the back tires on grass or gravel like many of us can. Not that I want to, it seems like there is something still needed.

I was wondering if my driven clutch might be upshifting too soon. It is the original 22 year old clutch that hasn't been touched. Maybe the spring is weak or I should adjust/swap the spring?

Re: Clutch And Gearing Adjustments
 

If that clutch is 22 years old, I'd replace it if it was me. That big block engine has 3x the torque of the original engine, if not more. That clutch wasn't designed for that much torque to begin with, and after 22 years it can't be up to the abuse the new engine is giving it.

Re: Clutch And Gearing Adjustments
 

So would you rebuild with a stock 36 degree cam, new buttons, and new spring then a little more preload to keep the rpm higher when driving slowly?

Re: Clutch And Gearing Adjustments
 

Another area to consider here how linear is your throttle plate movement versus your gas pedal. The clone carbs use a very small amount of movement to go from idle to wide open where as the gas pedal end of the system produces a large amount of movement so is wise to see when your throttle is wide open in relation to your gas pedal.Most of the time if this isn't correct you get a very jumpy cart at low speeds.

Re: Clutch And Gearing Adjustments
 

With the release of the throttle anchor bracket from VC it allowed me to better regulate the pedal to throttle relationship. My situation isn't really caused by a too-sensitive throttle pedal. More I would like it to stay in low gear a bit longer before it shifts into high ratio. I don't want to raise the drive clutch engagement rpm, just have it hang in low gear a bit longer so I can be more like 2500 rpm and still under 8mph. The taller rear gears contributed to the issue but it seems like the driven clutch may be responding too early.

I probably didn't state my thoughts perfectly in the opening post.

Re: Clutch And Gearing Adjustments
 

On a yamaha you can change the secondary clutch preload by using the different letter # combo's. Also by adding a stiffer secondary spring. Alas I don't know what is possible on the EZGO brand. It is funny I had to experiment with primary spring set up on my HD cart and both primary and secondary set ups on my yamaha to get them both to shift over as quickly as possible

Re: Clutch And Gearing Adjustments
 

At this point I would invest in the 780 comet primary. The 780 should more than handle the power from your engine, they typically engage around 1600-1800 rpm. This clutch is proven to offer years of smooth engagement. About $250 landed.

The shift profile is typically controlled by the secondary clutch. With a performance secondary, you will have more aggressive angle on the sheaves as well as a heavier spring. This will give you more low end because it will not upshift out of as quickly, staying in "low gear" longer. It will also allow a quicker downshift, so if you are cruising along and punch it, it will really take off. Again about $250 landed.

Make sure you get a heavy duty belt, like a Kevlar type. The added torque will require a little better belt to stand up to the heat/friction and also to last longer.

Re: Clutch And Gearing Adjustments
 

The drive clutch is the VC 780R that came with the 625 engine kit. It engages at around 1700-1800. It seems like the secondary starts to shift at about 23-2500 which is fine if all I did was street riding. But I do a lot of slow speed driving at 5-8 mph. At the 8 mph mark it really starts to want to shift into high gear. Per my seat of the pants guess. I would rather see it wait until after 10-11 mph.

Re: Clutch And Gearing Adjustments
 

I watched you work through that and thought my situation was opposite too. Hopefully I will be as successful as you were.

Re: Clutch And Gearing Adjustments
 

Oh I misunderstood, I thought you said the clutches were original.

Ok so we are dealing with the secondary then. Invest the money in an EZGO performance secondary. I had a TXT and used the heavy spring in the stock clutch, no good. It was way too stiff. It wouldn't shift at all until you rev it up past 3k. I switched to the performance clutch, much much better. There are also different springs you can get, as well as clock positions on the clutch for the spring preload as Ray suggested. It's not the same as the Yamaha clutches and the spring is way more difficult to deal with. But the idea is the same.

What you want is for the engine to rev up more before shifting correct? A performance clutch will do this.

Did you talk to Aaron about your dilemma? I'm certain they have run into this before and likely know exactly what you need.