Predator Go Kart dying under load.

[DeKonB]

I have a pretty large 2 seater go kart with a 212cc predator engine. It has a stage 1 kit with upgraded intake and exhaust. The kit also came with a new carb. It has a torque converter. With the torque converter belt off the engine runs and revs fine with no issues. But once the belt is installed it wants to die on takeoff and I can’t go down on my throttle very much while moving because the engine keeps killing itself. Also my drive pulley got hot and my belt started to slip and now my belt is in pieces

 

[Denny]

Cheap not a Comet belt will do that. And it sounds like your carb is plugged up. Take it off and disassemble and thoroughly clean it and all small orfices.

 

[DeKonB]

Cheap not a Comet belt will do that. And it sounds like your carb is plugged up. Take it off and disassemble and thoroughly clean it and all small orfices.

I have already taken carb apart it is brand new and I’ve dug into it.

 

[ezcome-ezgo]

What sizes are the sprockets? Tooth count?

 

[DeKonB]

What sizes are the sprockets? Tooth count?

I’m not 100% sure on that. I can count them but I don’t get home for another couple days. Ik the sprocket on the axil is pretty large and then whatever sprocket came on the torque converter

 

[bob58o]

Too heavy, Too large diameter of rear tires, too small of rear sprocket, too big of front sprocket.

You’ll want at least 6x the number of teeth on the rear sprocket compared to the front sprocket.

60:10, 66:11, 72:12 …

Also probably time to disassemble the front pulley to clean and inspect. Make sure TC alignment is good. Use quality belts. Comet makes good belts.

If tires are really big… 19” 20” 22” …. Instead of 6x, I’d try for 7.5x. Like 8T on the front and 60T on rear.

 

[bob58o]

If 7.5 : 1 gear ratio doesn’t get you all the TQ you need, swapping the 6” driven unit for a 7” driven unit will increase the amount of torque to the pavement by about 15%.

IIRC
6” is 2.68 :1 in Low
7” is 3.12 :1 in Low

 

[bob58o]

.. the engine keeps killing itself…

The saddest GoKart story I ever heard.

 

[Master Hack]

You don't say what kind of carb it is.
My guess is carburation. Start adjusting, but first make note of where things are, so you can return to yer starting point.
If its a Chikuni carb, l wouldn't know what to tell ya.

 

[Darren]

What ever carb you have, get a jet kit for it. plenty on ebay. Take the pilot and main jet out, have a look at the numbers, these represent the size of the hole (usually size in mm, say 32 for pilot 0.32mm 135 for main 1.35mm) look at the colour of the spark plug tip area, dark tan is good indicator of your ideal stoichiometric value. If you have a needle put it at mid position as a start point. Black66 has a great number of videos on YT for tuning carbs.

 

[DeKonB]

What ever carb you have, get a jet kit for it. plenty on ebay. Take the pilot and main jet out, have a look at the numbers, these represent the size of the hole (usually size in mm, say 32 for pilot 0.32mm 135 for main 1.35mm) look at the colour of the spark plug tip area, dark tan is good indicator of your ideal stoichiometric value. If you have a needle put it at mid position as a start point. Black66 has a great number of videos on YT for tuning carbs.

i ordered a rejet kit with .036 and .037 main jets and re jetted the carb. And tuned it and it is still acting up. No matter where the mixture screw is it still has trouble. I think I’m just gonna swap the engine for a vtwin 16hp or so engine. And just do a torque converter for a 1” shaft and not do modifications. I was told when I got the kart that the engine ran amazing before the stage 1 kit was installed then when he installed the new carb the kid “didn’t know how to tune a carb” so he couldn’t get it to run right. So I’m gonna stick with a stock larger engine

 

[DeKonB]

You don't say what kind of carb it is.
My guess is carburation. Start adjusting, but first make note of where things are, so you can return to yer starting point.
If its a Chikuni carb, l wouldn't know what to tell ya.

 

[Master Hack]

That's certainly one way to fix it.
Just remember, then you have a goverened engine. You might sacrifice top end, cuz yer governed to 3600 or so. Remove the governor and then.... it might not end well.
Gearing might help, on and on.....
So yer spending a bunch, just to have a new set of problems.

 

[Denny]

That's certainly one way to fix it.
Just remember, then you have a goverened engine. You might sacrifice top end, cuz yer governed to 3600 or so. Remove the governor and then.... it might not end well.
Gearing might help, on and on.....
So yer spending a bunch, just to have a new set of problems.

Yea, but think of the torque he will gain with a 16hp v!

 

[Master Hack]

Yea, but think of the torque he will gain with a 16hp v!

True dat! Lotta money and work for what might be a simple problem.
I have to make my shyt work, cuz my inner tightwad won't let me spend money unless there is mo other option.

 

[Darren]

Sorry didn't realise you had a standard carb with an aftermarket air filter. The gaskets have to go on the right way, there's an air circuit that's part of the carb, the gasket will block it if not installed correctly, very easily done.

 

[panchothedog]

Post # 16 is absolutely correct. Very easy to get the gasket upside down, or flipped left to right. Can't tell from your photos, but there is also a phenolic
( looks like black plastic ) spacer that goes between the carburetor and the head.
If any of these are missing or installed incorrectly, the engine won't run properly,
if at all. Download the predator owners manual. There is a good exploded view on how it all goes together. You don't need a new engine. The kid you bought it from botched it when he replaced the carb. Sounds like you have followed him on the way to frustration.