Torque converter replacement- kit or just drive clutch and driven unit?

[mdavis20]

hello all, new to the site and a newbie with go karts. Have a manco 706-b with a comet 30 series torque converter that I’d like to swap with new parts (driven unit doesn’t seem to open up properly as the rpm’s climb). I want to go ahead and get a new drive clutch while I’m at it. I see the full kits out there complete with mounting plates and covers, but I think I only need the drive clutch and driven unit. My kart has a thin black sheet of metal that acts as a mounting plate I think, but it doesn’t look like the thicker plates that come with the kits. Question is: Do I need a kit, or is it ok to simply replace the driver/driven units? (Pictures attached for reference, already started to take some bolts/nuts out).

 

[Denny]

It should be ok to just replace the drive and driven units. And use ONLY GENUINE COMET BELTS.

 

[panchothedog]

You can probably buy a kit cheaper than the 2 parts individually. If so, then just use the driver and driven that come in the kit. BTW, the plate systems work very good.

 

[mdavis20]

You can probably buy a kit cheaper than the 2 parts individually. If so, then just use the driver and driven that come in the kit. BTW, the plate systems work very good.

Thanks for the response. For what I am seeing for genuine Comet parts (not the Chinese substitutes), it’s $220 for the kit, but only $120 if I buy driver clutch, driven unit and belt separately

 

[Edwin Spangler]

Thanks for the response. For what I am seeing for genuine Comet parts (not the Chinese substitutes), it’s $220 for the kit, but only $120 if I buy driver clutch, driven unit and belt separately

The belts- go with comet, is what he means. The hard parts of the generic CVT, I dont see much of a difference in how they are built compared to the name brand stuff.

-And just for reference... Im seeing better performance from the most generic belts compared to the gopowersports belts.

The comet belts last at least twice as long as the other two though.

EDIT: Now that im thinking of it, Ive had a bunch of stuff from gopowersports just plain fail on me lately. Then they have some ridiculous requirements for return that make it ultimately impossible to get an exchange on faulty stuff.

 

[Sparkwizard]

Before you spend any money, have you tried cleaning and lubing what you already have?
A little maintenance goes a long way when you already have the quality parts.
Clean, lube, add a new belt and you might be surprised with your performance.

 

[ezcome-ezgo]

I'm no expert, but I think there are some bits missing here:

 

[mdavis20]

I'm no expert, but I think there are some bits missing here:

View attachment 152435

I certainly think I have an issue with the driven unit as it doesn’t seem to want to open up as the RPMs climb. But I’m definitely not an expert either and wouldn’t know how to diagnose what the issue is. I don’t have a problem just getting a new driven unit (and a new drive clutch and belt while I’m at it).

 

[Whitetrashrocker]

Looks like the spring is broke and missing the 3 rubber buttons.

 

[Denny]

And the nut to hold it on.

 

[mdavis20]

And the nut to hold it on.

lol, yes. Already started the process of taking it off before snapping a picture.

 

[panchothedog]

You probably can repair your current driven. You are clearly missing the plastic stops and more than likely need a new spring. About $20 to $25 in parts. If you are not capable or interested in trying to repair it, the cheap $65 torque converters sold on Amazon work absolutely fine. I own 5 of them and some of them are pretty old and still work good.
FWIW, I have done thousands of dollars in business with Go Power Sports over the past 5 years. ALWAYS got quality parts from them and the two times they accidentally sent the wrong part returning and exchanging went well. Sometimes a pleasant attitude and a little patience go a long way.

 

[mdavis20]

A couple follow up questions:
1. Is it normal to have a 9 tooth sprocket on the jackshaft? Most other sprockets that come in kits seems to have 10 teeth or more? My current one is 9, and I assume I need to stick with 9?

2. When sliding the sprocket off the jackshaft, it needed some convincing at points along the way as the keyway seems to have a few rough spots preventing free movement. When working the sprocket down the keyway, I dislodged a collar of some kind that was supporting the jackshaft and it became wobbly. I was able to push it back in and seems to stay in place, and the jackshaft is no longer wobbly. but should I be concerned this will easily come out and the jackshaft become wobbly again? Or once everything is on and secure it’ll all stay in place ok?

 

[Denny]

9 is fine. Once it is all bolted back together tight it should be fine.

 

[panchothedog]

Once everything is on and bolted down it will stay in place. With nothing on the jack shaft they slide in and out ( and get wobbly ) quite easily. You mentioned rough spots, burrs. This is quite normal. Take the shaft, the key, and the sprocket, clean with alcohol or break parts cleaner, and then some 320 grit wet and dry sandpaper and sand EVERY corner slot or edge there is. If yours is comet I guess it was made hear, but everything else comes from China and is loaded with burrs and rough edges. Clean in the same manner after you get everything fitting nicely. Also grease both the jack and engine shafts. It will go together easier, but it really makes a difference on disassembly. A 9 tooth will give you a little bit more hole shot, but will top out a little slower. Most run 10's. Depending where and how you use it, and tire size. There is no right or wrong. Try them both and see what suits you best.

 

[Pcorbin]

You might need a reverse wound spring since you have mounted the driven pulley in the outward position if your crank turns counter clockwise you will definitely need a reverse wound spring. I know this because I had the same problem. I just purchase an older Carter Bros go kart it came with a predator 420CC motor and the driven pulley kept slamming in the full open position when I applied power to the motor, once I put the yellow reverse wound spring in the pulley it solved all my problems now I am crushing about 50 to 60 MPH with this engine. I also put a stage 1 kit in it and removed the governor. This motor screams now. You can go on Red Beard Garage on Youtube he will show you haw to change out the spring to a reverse wound spring.

 

[panchothedog]

You might need a reverse wound spring since you have mounted the driven pulley in the outward position if your crank turns counter clockwise you will definitely need a reverse wound spring. I know this because I had the same problem. I just purchase an older Carter Bros go kart it came with a predator 420CC motor and the driven pulley kept slamming in the full open position when I applied power to the motor, once I put the yellow reverse wound spring in the pulley it solved all my problems now I am crushing about 50 to 60 MPH with this engine. I also put a stage 1 kit in it and removed the governor. This motor screams now. You can go on Red Beard Garage on Youtube he will show you haw to change out the spring to a reverse wound spring.

You have a 40 series torque converter. This one is a 30. He needs the plastic stops and a new ( not broken ) spring. I don't believe that there is such a thing as a reverse wound spring for the 30's. But they sure make a difference in the 40's.

 

[bob58o]

Late to the party and I not read good.
Did the kart ever perform great? Do we know the tire size and rear sprocket size? I only ask because if you need more torque for your kart, a 7” driven unit might be better for your situation. The standard 6” driven unit gives you around 2.7 :1 in L and 0.9 :1 in H. The 7” gives you around 3.1 :1 in low and 1.1 :1 in high. The 7” gives you 22% increase in torque in highest gear … and will make it easier for your clutches to shift fully.