Predator 670 - Shifting & Governor Help Needed

[cadman777]

Hi,

This is my first post in this forum. Been reading a lot of threads in an attempt to 'get edjumakated' on the subject.

This concerns a ClubCar long golf cart with a predator 670 engine retrofit.
My neighbor took it to me b/c I'm the 'neighborhood mechanic'.
This has quite a learning curve!
Anyway, I finally got the engine running decent (original carb!), but now it rides all out or nothing. I noticed 2 things I'm struggling with:
1. The engine governor keeps fighting the gas pedal. So I am constantly having to 'feather' the gas pedal to get it to run at a steady rpm.
2. When I get the rpm's to a certain point in an attempt to get the mph down to nice easy ride (like around 10 mph), the clutch cycles in and out and the mph's die. In order to get it up to speed again, the throttle has to be 'feathered', which is a PITA.

Some pertinent info:
1. The engine was 'hacked', so the springs and throttle setup only has the engine governor connected to the cross-link that actuates the carb throttle plates. Also, the throttle cable is connected directly to the engine's governor lever. I really want to eliminate that governor, b/c it pushes real hard against the throttle actuation, but I'm not sure if that will be a problem with red-lining the engine. If so, then I need a fix for the governor over-powering the throttle.
2. The governor on the rear dif. is disconnected, so it doesn't play into this scenario.
3. Otherwise, the engine is stock with a better spark plug (the guy bought Champion, I would have bought NGK...whatever!).

Any help is appreciated!
And thanks to all the members who have made this a very informative forum!

[TheNewGuy]

I ran the cable from the pedal to the throttle plate on many carts with several different engine setups. No mechanical governor at all, your foot is the governor. I also installed a tachometer to monitor RPM. The cable can be adjusted so the throttle plate won't open all the way.

[cadman777]

Excellent, thanks, that's what I want to hear!
That'll be my next move on this machine.
I'll report back on the outcome when it's done.

Can you recommend a good waterproof tach that's reasonably priced?

[sho305]

There is only a couple tachs that work, Vegas had one and there is a equus or something you have to get it with the pickup for the small engines. You can run straight throttle just dont hold it on the floor for a mile that might not be good. Usually they wont pull that much rpm stock anyway. You might get better valve springs it depends on the engine. Second best is use the trans governor but at higher speed they will fight the throttle also. If you just want to check rpm you can get the little digital mower ones but they arent that great and most only last a few years and go dead. Stock my G9 cart and later with a clone would do around 4600 and not much power past 4K. Now the clone is all built up it revs much higher.

[cadman777]

Thanks, I'll check it out.
It's not my ride, so I can only tell the guy not to blow it up.
My goal is to make it run slow and if he wants fast, then he can have it with the press of the pedal.
Thing is, they disconnected the dif governor, so I don't even know if it works. The lever flops around and there's orange permatex around the seal. My guess is they opened it up and removed the governor parts. So that one may not even work.

[slonomo]

The Equus 8068 is the tach that most of us use for big blocked carts. With that said, it doesn't always work with the 670. I don't understand why, I just know I have had 2 of them and I couldn't get it to read correctly. There are some threads about it on the forum, but I went to Google to find info. Some have figured out a way to wire the tach to the coil without using the inductive pickup connector, and that worked. It seems there were a few different ignition systems used, different parts sourced from different parts of Asia kinda thing. Some systems will work, some will not, no one really knows how you know what system you have and if it's the type that will work or not.

That same Equus 8068 worked on my Vanguards, clone, and VC440/460 engines. I also used it on a Kawasaki mower engine once. All using the inductive pickup.

I gave up on using a tach on the 670's and used my "ear" and learned not to run it hard.

"The New Guy" is right, just bypass the engine governor and run the throttle cable direct. You can find some videos on that, but if you've rigged up throttles before you won't have any trouble. Might have to fabricate a little bracket and such.

"Sho" is also right about the rpm. These engines shouldn't run past 4600 rpm if you want them to last. If you build the bottom end you can, but even then, you have to remember these are tractor engines lol.

[sho305]

Yeah my 420 hit 42 gps with 22 tires and stock gears, then the steering got a little strange lol. I don't run it on roads so I never go that fast normally. It also blew oil into my fuel pump doing that. They say the cam will run 6K rpm. But it runs good on trails it pulls a lot harder now and thats all I wanted. Its too bumpy to get much over 30-35mph or I run out of room. My clutch shifts at 4200 rpm when I last checked it, at about 30mph the rpm climbs after that. Running a pumper slide carb now with a foot long intake the carb is over the crankshaft, due to in the G9 the stock carb is out back in the dirt. And it has a rod, cam, head cut, shaft rockers, etc.

But like I said stock cam and engine usually they puke at 4600 and you usually wont damage them if you don't keep it there long just run a little less than max rpm. If you run roads you will have to deal with that, I'd kill myself going fast on trails and stuff lol. Some people adjust the governor to 4K rpm and run it stock that way, I took my governor out and plugged the hole. It just works better without a governor, the throttle works better.

[cadman777]

Thanks for the info Slonomo. I'll keep it in mind.
Today I spent 4 hours welding up all the cracks in the main frame and one of the seat frames. Tomorrow I'll work on the front end frameworks.
Man is this think a mess!
Then I'll try that direct connect to the carb throttle plates.
Do you guys think the driven clutch on the rear dif is activating too soon, and maybe I need to put new springs in it?

[cadman777]

Sho, thanks for the info on the RPMs.
I think I'll add a tach so the guy doesn't blow his engine, b/c he likes speed!