Manco 415 Torque Converter conversion

[bthompson224]

Hello, all. After a couple of days of reading, I'm still a little confused. While mechanically inclined, I don't know much about karts. We currently have a Manco Critter II, single wheel drive with a Tecumseh 5hp. Since my daughter drives it, there is a lot of stopping and starting. I am thinking of changing to a TQ setup. Is there a direct bolt on kit? Worth it for a single wheel drive? I will be tearing into this weekend to tune and lube everything. From the owner's manual here are what I think are relative specs.

3/4 shaft
Chain #35 86P
Sprocket on the axle is 35P 80T
I think the sprocket on the clutch is 10T

 

[JTSpeedDemon]

Pretty typical sized engine.
#35 is the pitch of the chain, I don't know what you mean by 86P.
With an 80T sprocket, and an ~10T clutch, that makes for a gear ratio of 8:1.
Pretty torquey.
But also, how large are the tires in diameter? That can make or break some gear ratios.
Ohh also, if you do have a #35 10T clutch, that's awesome! I want to find one for my kart, but I've never seen one.
More likely, you have a 12T clutch.
80/12=6.6/1 gear ratio, which is just about perfect for general karting.
As for if you should get a torque converter, for stop-and-go, yes.
Although you could also get away with a centrifugal clutch as long as you try to keep engine rpms above engagement rpm.
Keep in mind that torque converters will be more expensive.
Yes, they are usually bolt-on, but I'm not totally sure if most would work on a Tecumseh.
If you wanted to have a really good setup, you'd get a live axle, slap a TC on a Predator 212, and you'd have a really nice kart for your daughter.

 

[J.S.@SMS]

A 30 series tav kit should work fine on a Tecumseh with a 3/4" shaft. Although it may require moving the engine plate. And live axles don't like turning if there isn't enough weight in the front. And as long as the carburetor is good, and you're happy with the current engine, I see no need to replace it.

If I were you, I'd go with a higher quality clutch, like a Max Torque. It should hold up better than a cheaper clutch. Also, you'd be able to keep the existing setup.

 

[JTSpeedDemon]

 

[bthompson224]

Yeah, after looking further it is a 12T. It's a basic stock setup. Tires are 145/70-6. Everything works great, just thinking of the stop start wear and tear, and also it might make it more fun on the low end. It's plenty fast for her right now. If she decides she really wants to go fast, there are plenty of race ready karts in the area for a little more than what I could sell this one. Previous owner had a similar situation with small kids. He got the clutch so hot the cover was melted a little. As to any mods, it would be cheaper to get another frame with the live axle already setup for a TQ.

 

[JTSpeedDemon]

Ok, thanks for the extra info.
Replace that clutch if you haven't already!
Don't worry too much about the clutch as long as your daughter isn't "slipping" right around the engagement rpm.
If she's happy don't worry too much about it.
In other words:
Don't fix it if it ain't broke!

 

[bthompson224]

Thanks, all. Looked at the Max Torque clutches, tons of spec info, no idea what it means. I assume it's just a regular six shoe for a # 35 with a 12T. All that about keys and set screws, not even sure where to look at on the existing clutch.

 

[JTSpeedDemon]

Don't worry about stuff like how many shoes it's got.
As long as the clutch sprocket and the inside diameter match, you can go ahead and order it and it should work just fine.

 

[bthompson224]

I'm all about keeping this simple. Gonna order now. Looks to be a straight forward remove and replace.

 

[JTSpeedDemon]

Should be anyway.
Good luck!

 

[bthompson224]

Thanks again!!

 

[Karttekk]

If you haven't picked up a clutch yet, this is what you need. GoPowerSports has outstanding support also. Call them, they'll be glad to help you out.

https://www.gopowersports.com/12t-3-4-bore-max-torque-centrifugal-clutch-35/

 

[bthompson224]

Clutch is on. Just an FYI, I spent 30 minutes trying to get the old key out of the original clutch before I realized it was integral. Lesson learned. Amazingly Ace Hardware has a huge selection of keys. I will say that I got the clutch from another vendor (can I mention them here?), and due to some shipping issues are sending me a key for free. As for GoPowerSports, I found out they are 20 minutes from me. I did order the same clutch as linked above. Wish I knew that 2 weeks ago....

Thanks again for all the advice.

 

[JTSpeedDemon]

As for GoPowerSports, I found out they are 20 minutes from me. I did order the same clutch as linked above. Wish I knew that 2 weeks ago....

Aha! So you're not too far from me!
We live within driving distance of GoPowerSports!

 

[bthompson224]

Yup, we're in Arlington.

 

[JTSpeedDemon]

DUUUDE!!!!
I'm in Arlington, too!
Are you going to the Pate Swap Meet this month?

 

[bthompson224]

I haven't been to that since they held it at the Pate Museum outside Cresson. Sorry, but I can't anyway, family stuff.

 

[JTSpeedDemon]

Ahh, that's too bad.
Family stuff is probably the #1 limiter in powersports besides money.
It's my first year going, and it's my main birthday present this year. (My birthday's tomorrow!)
Besides the trip itself, I'm getting a budget to spend there along with my own money! So my goal is to get my go kart into simple, working condition, and then be REALLY open to ideas there.
I may get some insane idea!
And when I say simple working condition, I mean I'm not even going to make a seat for it!
I'm just going to slap a pillow and the rotten seat back on there!

 

[J.S.@SMS]

Yeah, sometimes family can be a pain. Especially when your dad won't let you build a small frame that you have into a drift kart saying that I should, "Just get it running and sell it. then use the money for something else."

 

[JTSpeedDemon]

SHEESH!
At least my family supports my karting so it'll lead into a career!
My dad has suggested that I "flip" my kart(fix it up and sell it), and I might do that someday with another kart, but this is my first kart, so I'm attached to it anyway.