YERF Dog topspeed only 24mph!!!

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RealliveMD

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I weigh 215. My kids 2 seater standard go kart has a 5hp tecumseh and runs 32mph with me in it. The Yerf Dog which is basically stock with better front shocks runs 24mph. The green spring is in position 2. How can I get fast enough to keep up with my kids? Steering gets hairy at 24mph though. Money is not a huge deal to me. Just need advice.
 
r_chez_08

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First I would check that the engine is revving fully/ your clutch is operating correctly.
Enter your sprocket teeth number and wheel size here, and put your engine rpm as 3600. if you get 20+ mph then your engine and clutch are operating correctly.

Whats your torque like? if your torque and acceleration is fine, then you can adjust the spring so that it is in the hole with the least tension.
You can also change the gearing by putting a SMALLER axle sprocket, bigger wheels or a BIGGER clutch sprocket on the kart for more speed.

You can also remove the governor on your engine. The governor is what stops your engine revving higher than 3600. if removed then you can get up to about 5000 rpm reasonably safely, and you will have a top speed of approx. 33mph!

Can you find out what engine both karts have and the gearing and wheel size on both karts?
 
B.M.800

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Do you have a TC? You could fiddle with the govoner, you get a different sprocket too...

oooh, posted to late lol.
 
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I have a comet 30 series. I will have to measure the tires when I get home. I know that everything on the yerfdog is stock though. The other go cart just looks like your typical bench seat go cart with roll cage for kids, low to the ground, no suspension, one tire pulling. 5hp tecumseh. I know it's probably the weight of the yerf dog. I just wasn't sure what the factory top speed should be. Also, I though changing the tension spring would simply allow the car to go into high gear faster but not increase the speed.
 
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Is the governor external? Also, I just read that the yerf dog should be doing 30-35 mph. so I'm guessing my torque converter is never reaching high gear.
 
r_chez_08

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RealliveMD said:
Is the governor external? Also, I just read that the yerf dog should be doing 30-35 mph. so I'm guessing my torque converter is never reaching high gear.
Click to expand...

Governor is most likely internal. What engine have you got?
Maybe you have a problem with your engine? Does it sound like it revs fully?

What are you measuring your speed with? Maybe that is inaccurate?

Try putting it on a jackstand and revving it up to see if the torque converter works correctly. If it doesnt try cleaning the clutch that is showing the problem.

If it does it is probably an engine issue. Maybe your foot pedal is not allowing the full sweep of the throttle? It could be getting stuck.

Post a vid of the kart on a stand and count sprocket teeth numbers and check tyre size. If you didnt buy from new it is possible that the previous owner changed one of the above variables.

Hope that helps
 
Blazkowiez

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The thing you might want to keep in mind is that the yerf-dog is a much larger kart with an engine that really isn't any bigger essentially.

What should make this kart to faster than the smaller kart?

I understand that everyone's answer is jump the governor, but doing so on that Tecumseh WILL lead to engine failure. Granted that you said money is not an issue, perhaps you don't care about buying a new engine. I'll throw out my 2 cents on the suggestion once we get some more info, but understand I don't expect that kart to do anything more than 28 with the stock set-up assuming I know what kart you're talking about (i've got a picture in my head of the one you will end up posting.)
 
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The video didn't work but the torque converter is engaging like all the ones on the YouTube videos. The new belt is fraying on the sides so something probably needs adjusting. I'm posting pictures of the karts from this crappy iPad just to give you an idea of what I'm speaking about. The yerfdog is huge compared to the kid's kart. Actually it seems that the program doesn't support macs. Pics in 15 min.
 
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So, just to clarify, The last pic is the kid's go kart. The clutch is engaging properly, It runs fine on smooth terrain but it stalls and I have to pat the gas on bumpy terrain. I keep it full of gas and actually a little overfull on oil. ( I've heard of an oil sensor, but not sure where it is). Thanks for any input guys. .... and when I say money doesn't matter, I'm only saying it because we're dealing with go karts in the $100's range. I'm not rich by any means.
 
Bluethunder3320

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i doubt those motors have low oil sensors. because theyre made for go karts.

dont overfill the oil. this just makes too much crank case pressure and oil could get blown out the breather or up the cylinder.

i think its running lean if you have to pat the gas.

on my clone i bored out the stock jet a tiny bit with a torch tip cleaner and it runs very strong. they (as late model tecumseh's) came very lean from factory.

how does the engine run with no load?
 
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Bluethunder3320 said:
i doubt those motors have low oil sensors. because theyre made for go karts.

dont overfill the oil. this just makes too much crank case pressure and oil could get blown out the breather or up the cylinder.

i think its running lean if you have to pat the gas.

on my clone i bored out the stock jet a tiny bit with a torch tip cleaner and it runs very strong. they (as late model tecumseh's) came very lean from factory.

how does the engine run with no load?
Click to expand...
Runs fine with no load and on even pavement. Only stalls if wot on bumpy terrain. If I let off the gas. It doesn't cut off.
 
machinist@large

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RealliveMD said:
Runs fine with no load and on even pavement. Only stalls if wot on bumpy terrain. If I let off the gas. It doesn't cut off.
Click to expand...

Is this particular unit using a fuel pump? It sounds like it might be starving, but only over rough terrain? Have you checked the float setting in the carb? Some carbs for automotive street use don't work very well in off road trucks because the float setting/ layout have to be changed.

What about ignition issues; have you double checked to make sure you don't have any loose/ chafing wiring? As I write this, I'm begin to think the wiring might need to be checked as well. The wiring wouldn't bounce around much on smooth surfaces, but a lot over rough. Worth a look.

That's all I can think of without the toy in front of me. Hope it's of some kind of help. Pat H:thumbsup:
 
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