My Murray go kart build!

[rangejunkie]

Ok Ian going to try and update this as much as I can. Here's some backstory: bought the kart off Craigslist for $250, there was gas in the oil. So I tore the carb apart and got it working right, changed the oil, and presto it cranks right up.then tuned the carb (best you can with the stock one) and she runs like a champ. Today I put two new front tires on it and the guy I bought it from is giving my some of those small tractor tires for it tomorrow (20 inches). I ordered a mikuni carb for it with adapter and I am going to build my own exhaust. This is gonna be a mud and trail kart.
If y'all have any input on how to do something or any ideas for modification or adding or just making it better, let me know I'm all ears.


Specs: (sorry I don't know the tec terms, feel free to correct)

6.5 clone / blue gas tank (GX200) stock

60 tooth sprocket

10 tooth drive sprocket.



Soon to come:

Mikuni carb

High intake air

Straight exhaust

Possible governor removal

20 inch mud tires

Custom roll cage

Custom rack

4point seat belt with off road seat.



Here are some pics so far. Sorry for all the typing. Also how do you find out what year these things were built?

Oh yeah mods I know this is up in another part of the site. I am sorry but couldn't figure out how to move it. Once again sorry for double posting.

 

[rangejunkie]

Oh yeah I'm new to the whole go kart thing and this site has been awesome so far. Thanks.

 

[landuse]

Nice kart. Even though you have a TC, you MIGHT have some gearing issues with 20" tyres. I am not saying you will, but with 6:1 ratio and 20" tyres, I would gear the TC to at least 7:1

 

[rangejunkie]

Ok I don't know the answer to this so how would I go about doin that. Gearing the TC

 

[rangejunkie]

Changing the sprocket on the axle to a 70 tooth?

 

[landuse]

Changing the sprocket on the axle to a 70 tooth?

That is correct sir.

 

[rangejunkie]

Thanks. I'll look into it.

 

[rangejunkie]

Could I change the 10 count sprocket to a 20 and get the same results?

 

[landuse]

Could I change the 10 count sprocket to a 20 and get the same results?

If you do that, you will be raising your gearing, not lowering it. With a 20T your gearing will be 60/20 = 3:1. With his ratio you will shred belts in literally 10 seconds flat and not move an inch. What you want is a lower gear ratio, not a higher one.

With a 70T and a 10T, your gearing will be 7:1. The higher the number, the lower your gear ratio and the more torque you have. Speed is comprimised a bit though. It all works the other way round with higher gearing.

 

[rangejunkie]

Hey land use. Quick question. If I changed my 10 tooth to a 5 tooth would that work. Only reason I ask is because I am looking into getting more torque for bigger tires and am concerned with ground clearance.

 

[Cjhoward78]

Then u get 14:1 ratio. More torque less speed. With the 70 or 12:1 w the 60 60 w a 8 gives u 7.5:1

 

[landuse]

Hey land use. Quick question. If I changed my 10 tooth to a 5 tooth would that work. Only reason I ask is because I am looking into getting more torque for bigger tires and am concerned with ground clearance.

Unfortunately you will never get a 5T sprocket because it is just physically impossible to get only 5T on a sprocket. As far as I know a 9T is the smallest you can get, and I think that is with a #40 chain. I can stand corrected. If you cannot use a sprocket larger than 60T, you are going to have to invest in a jackshaft for compound gear reduction using smaller sprockets.

Then u get 14:1 ratio. More torque less speed. With the 70 or 12:1 w the 60 60 w a 8 gives u 7.5:1

Correct. Unfortunately I don't think you get a 8T either. You only get certain sizes for TC's

 

[rangejunkie]

Oh ok. I didn't really know. I just kinda threw a number out there. Looks like either a jack shaft or a modified sprocket cover are going to be in order.


If you can't decide to go left or right..... Put it in 4 Lo and just go straight.

 

[yerf_dogger]

they do have 8t sprockets. I just ordered one and installed it on my sons yerf-dog.

Made a huge difference on low end torque and acceleration.

http://www.mfgsupply.com/gomini/gom...tsdrive/gominisprocketsdrive58c40/az2182.html

 

[rangejunkie]

No I do not, I am lookin at all my options. Before I order anything.

Oh yeah, BTW my mikuni carb came in today. But now I have to get a new throttle cable, and I should be getting my air filter in sometime this week.