Clutch

[Michael james]

I was thinking of getting a Honda GX390 engine for my drift cart
The original engine GX200 clutch is F*** so I am going to buy a new one, problem is I dont know witch one to buy OR witch PTO shaft for my GX390 the engine is at http://engines.honda.com/models/model-detail/gx390
PLEASE HELP!

 

[Russ2251]

You want the "Q" type PTO shaft which is 1" in diameter.

 

[r_chez_08]

You can get either a 1" centrifugal clutch or a 40 series torque converter. I have one of these i could sell you. IMO the torque converter is a much better choice, i swapped a cent clutch for a torque converter and the power seemed to double.
Rob

 

[Michael james]

would a torque converter have better speed and acceleration.I am not shure how they work

 

[Michael james]

Do they have better top speed and acceleration. I dont know how they work.

 

[devino246]

Do they have better top speed and acceleration. I dont know how they work.

Yep and yep.

There are no gears, no complicated controls or levers and neither manual shifting nor clutching is involved in these systems. The unique design of the movable face in each "driver" and "driven" member causes automatic, infinitely varying and thus smooth shifting action between the system's low and high range ... with constant optimum ratio between engine and drive wheel. Since these devices consist of a belt and two variable pitch pulleys all working together harmoniously, serving as both clutch and transmission, they are often called a "variable speed drive system". Weather-proof, completely mechanical and occupying minimum space, they can operate mounted in any position and are adaptable to a wide variety of applications. Each Comet System is fully automatic and can be used anywhere that control by engine throttle alone is desirable. Since ratio selection and "down shifting" is automatic, braking and vehicle control are enhanced. Even engine and drive train component life (sprocket, chain, bearings, etc.) is extended since shifting is smooth and not subject to the hazards of manual control. The years of Comet engineering experience, fine materials, special processes and control procedures for quality that are used in the manufacture of Comet Torque Converter Drive Systems are without peer.

 

[Michael james]

 

[r_chez_08]

the torque converters basically double your power, and increase your speed by 10%.
you can buy a cent. clutch for about $150 for a good one. i can sell you a torque converter for $330 brand new if you want (its a genuine comet one, hard to come by)
Rob
edit:
How does a torque converter work? The drive clutch is activated by centrifugal force from the engine crankshaft. The moveable sheave of the clutch is forced in as the RPM of the engine is increased. This contacts the drive belt. The drive belt will then be forced to a larger diamter within the clutch sheaves, thus pulling it to a smaller diameter within the driven unit sheaves. The moveable sheave of the driven unit is forced out, allowing the belt to seek its smaller, high speed ratio diameter. As this happens, the speed from the engine transferred to the final drive is increased.

 

[Michael james]

thanks

 

[r_chez_08]

they are really good- i put a 40 series on my go kart and it went a lot better and the clutch is a hella lot more durable than the cent. clutch i had.

 

[Michael james]

cluch

are they hard to install and would the type 40 fit my GX390
"Q" type shaft could you show me a pict does it fit on as easly

 

[Michael james]

my carts engine
shaft diameter is 1"

 

[r_chez_08]

the 40 series would fit onto your gx390 with a bit of fabrication and stuff.
The driver would slide right on, easy!
the driven needs a jackshaft: http://www.bmikarts.com/shop/?shop=1&cat=272
you would need a sprocket for the jackshaft. you can either buy one that goes under the engine or one that mounts by bearings welded to the kart.
rob

 

[Michael james]

getting a new GX360 engine mounted is hard. putting a torque converter on is
dam near impossable, where can you fit it on.I would happly pay someone else to do it for me. these is the go cart im going to put it on to.

 

[r_chez_08]

The jackshaft can go under the motor. Its up to you. I can get more measurements if you want, however could you grab me a pic of under the chain guard?
Rob

 

[Michael james]

I think im going to go with a cent.I will put a torque converter
on my other go cart

 

[Gator]

i think a cent clutch would be just fine on that kart, it looks light and isnt a hardcore off road kart, and would be easier for mounting room.

I just installed a gx340 clone on my kart, my kart its a little bigger than the one you posted, my kart is dead axle, from a dead stop on pavement i can bark the tire, turn left i can smoke it, the engine pulls me (250lbs) well. Its geared 10/60 and tops at 30mph ungoverened.

I used the noram 1600 clutch, its rated to 15hp. A step up would be the noram enforcer, ive read people using this one on 35+hp engines and doing great.

For that engine to fit you will need to make a motor mount for the larger eng bolt pattern, and you will probably need to cut the end of the frame off where it bends up and around the present engine.


Is your kart live axle?

 

[anderkart]

Do they have better top speed and acceleration.

Yep and yep.

Your first 'Yep' is spreading a total Myth here.
(cintrifical or disk clutches dont rob power from the additional friction/drag caused by a tight belt/spring-loaded pulleys and jackshafts like t/c's do!)

I guarantee you wont see competitive go karts with T/C's racing at the Bonneville salt flats or most any (sprint or oval) racekart tracks for those very reasons I mentioned. Clutches with a single drive chain offer higher top speed potentials!

But I totally agree with your second 'yep'.

T/C's do indeed offer the advantage of much better acceleration than any Centrifugal or Disk-type clutches. They are a much better choice for heavy or off-road/hill-climbing karts, or for any riders that do a lot of low-speed or stop and go type riding.

 

[r_chez_08]

I think im going to go with a cent.I will put a torque converter
on my other go cart

Ok, should be good. Whats your other kart?
Rob

 

[anderkart]

I was thinking of getting a Honda GX390 engine for my drift cart
The original engine GX200 clutch is F*** so I am going to buy a new one, problem is I dont know witch one to buy OR witch PTO shaft for my GX390 the engine is at http://engines.honda.com/models/model-detail/gx390
PLEASE HELP!

Depending on if your running a #35 or a #40/41 chain size and your gearing needs, I'd suggest a Noram Star or Noram 1600-series clutch:--> http://www.out2win.com/catalog/noram.html#1600

Or here's the best clutch available:--> http://www.out2win.com/catalog/noram_enf.html
But unlike those 2 above, it will hang way out at the very end of your engines output shaft. So it would require you to move the motor mount over a couple additional inches more to compensate, so your sprockets would line up...

You've also got some tough choices to make regarding how many teeth you want your clutch gear to have...

If you wanna "drift" or do any off-road/hill climbing, Id suggest you order your clutch with the smallest/lowest tooth-count available. (10 to 13 tooth) for the best acceleration abilities.

But If you'll be only riding in large, flat, hard-packed dirt or pavement areas and want the most top speed, you could consider a clutch in the 16 to 18 tooth range.

Or, a 14 or 15 tooth model might be good compromise of decent acceleration and top speed.

How many teeth are on your rear sprocket now?
and how tall are your back tires?
and how much will the drivers weigh?
and what type of terrain will you mostly be riding your kart on?

How many teeth were on your old gx200 clutch? Were you satisfied with the top speed and/or acseloration you got from that engine?

Keep in mind that your GX390 will have the same 3600 max RPM/top-speed unless you remove the engines Governor. But compared to a gx200, the GX390 would always have MUCH more torque, better acceleration, and you could choose to gear it for higher top speeds.

Here's a link to our speed calculator:--> http://www.diygokarts.com/speed-calculator.html
You should experiment and learn your potential top speeds with different gearing combinations, before committing to your clutch gear-size...