More torque?

[WTFboom]

I have a Baja DB30 Doodle Bug and it does not have enough torque to get me up small hills. I have to get momentum to conquer small hills. I have a 6.5hp engine that i was going to use for a go kart i was going to build. The speed of the bike know is fine. It would even be OK if it went slower. I have removed the governor and the throttle limiter screw. What i want to know is should i put that new engine in (i would have to get a new clutch bell, a 10T or a 12T but the 12T needs a #40 chain i have a #35). Or i can get a new rear sprocket (the stock is a 70T). I can get sprockets all the way up to 94T (I just have to drill my own mounting holes). Or should i do both to keep the speed down and torque up. So, what is the setup i should use?

EDIT: Just a question. I think a manual clutch would be lots of fun. Like on a dirt bike. Can i get one without a transmission?

 

[redsox985]

Either gear it low assuming you are using a cent. clutch, or upgrade to a torque converter. How do you plan on having a manual clutch without a transmission?

 

[KieranM]

you could use an tensioner clutch setup, where its belt driven, and you tension up the belt to engage the rear pulley.... if it is a centrifugal clutch is is worn/old?

 

[WTFboom]

Its a centrifical clutch. Nevermind what i said about a manual clutch. I kind of dont want a torque converter because they are very expensive.

 

[modelengineer]

A tensioner clutch is cheaper than a cent. clutch and is very different to a torque convertor.

 

[WTFboom]

A tensioner clutch is cheaper than a cent. clutch and is very different to a torque convertor.

How would i go about doing that? I am new to the mini bike and go kart scene.

 

[Blazkowiez]

The main problem is not your clutch, it is the engine. The doodlebugs have a very small engine and does have poor torque issues, if you do gear this low enough to operate off-road and power over hills you will have a very very slow top end. If you decide you want to be riding this bike around off-road with any form of power and speed you want to be upgrading the engine. I would honestly just say go to one of those Chinese 6.5hp engines, a 3/4" bore clutch with a 12t top that accommodates that #35 chain, we've had several customers do this conversion without the need for a torque converter and really enjoy the outcome.

 

[WTFboom]

The main problem is not your clutch, it is the engine. The doodlebugs have a very small engine and does have poor torque issues, if you do gear this low enough to operate off-road and power over hills you will have a very very slow top end. If you decide you want to be riding this bike around off-road with any form of power and speed you want to be upgrading the engine. I would honestly just say go to one of those Chinese 6.5hp engines, a 3/4" bore clutch with a 12t top that accommodates that #35 chain, we've had several customers do this conversion without the need for a torque converter and really enjoy the outcome.

Now because it is more than 2x the horsepower, will i get 2x the speed and torque?

 

[Blazkowiez]

Being a person of average weight you will gain approx 5mph but you will notice a strong difference in torque. Small engines typically have a max rpm of 3600 so they theoretically have the same top speed with the same gearing applied, however the 1.2 or whatever horsepower engine they have stock on the Doodlebugs seems to lack the ability to pull an adult at anything over 20mph.

 

[WTFboom]

Being a person of average weight you will gain approx 5mph but you will notice a strong difference in torque. Small engines typically have a max rpm of 3600 so they theoretically have the same top speed with the same gearing applied, however the 1.2 or whatever horsepower engine they have stock on the Doodlebugs seems to lack the ability to pull an adult at anything over 20mph.

Thanks. Yea its a 2.8 hp stock. I clocked it with a GPS speed app on my iphone at 30 mph.

 

[redsox985]

Go kart speedo...there's an app for that.

 

[Doc Sprocket]

Go kart speedo...there's an app for that.

Sure. But I'm not brave enough to risk fumbling my I phone at full bore...

 

[redsox985]

Haven't you seen Fowler's signature

You only need 2 tools in life: wd-40 and duct tape. If it doesn't move and should, use the wd-40. If it shouldn't move and does, use the duct tape.

Just duct tape it down to the center of your steering wheel. It won't kill your phone for one wide open stretch.

 

[fowler]

too bloody right

 

[redsox985]

Hahaha I love how we trust a fraction of $4 roll of tape to secure our multi-hundred dollar phones.

I'd trust this stuff

 

[fowler]

u should read some storys on the net of what people have used it for
a bloke was found in on the ocean strandand arfer he used duct tape to fix the crosion on his motor mount
the engine fell off

 

[WTFboom]

Haven't you seen Fowler's signature



Just duct tape it down to the center of your steering wheel. It won't kill your phone for one wide open stretch.

Exactly what I did.

 

[fowler]

ha ha ha u actually did it
gotta agree with redsox here

 

[redsox985]

I want some of that tape to put it through it's paces and see what it's capable of in comparison to regular duct tape.

 

[fowler]

make a boat out of the stuff like mythbusters and see if it lasts longer