Just bought a Yerf Dog 3203

[Revolt]

On craigslist pretty cheap but i'm wondering what modifications i could make to it to make it faster/ and also what i'd be able to do to the suspension to make it less bouncy. Thanks. Hurry back.

 

[modelengineer]

To make it faster (like much faster) you need to put a bigger engine on it. To make a little bit more power you can tweak the engine a bit by getting a new carburettor, straight pipe exhaust. After that, you have to start upgrading parts inside the motor and since we don't know what type of motor it is it's difficult to comment further.

Making the suspension less bouncy... if the shock absorbers on the kart have adjustable rebound then make it so it rebounds slower. Otherwise, you need to get new adjustable shocks.

 

[Revolt]

thanks man, i was thinking of upgrading the engine because the one thats on it isn't great. And i've heard it doesn't last long. What would you suggest? And how much are shocks?

 

[modelengineer]

I would suggest one of those blue 6.5hp clone motors for a really cheap, reliable and powerful enough engine.
If you're handy with a welder and want something that will be REALLY fun get a 200cc+ motorbike motor or a snowmobile motor if you're in an area where there are snowmobile engines.

Shocks can be found on ebay, not sure of the exact price. I imagine you don't need that much travel, having seen yerf dog karts before, so the ones on ebay should be fine. To be sure of eliminating bouncing you MUST get shocks which can be revalved for different compression and rebound rates. That was you can keep changing the valving until it has the characteristics you want.

 

[Revolt]

So are the shocks on ebay capable of valving? I really don't need the suspension to be honest.. and i can't stand the bouncing.

 

[modelengineer]

I'm sorry I really have no idea. You would have to find a specific shock and go to 'ask seller and question'. I've never bought shocks from ebay because I am getting some for free from a scrapyard. However, they are not suitable for a yerf dog as they are way too big.

If all else fails just get some square tube and drill holes in it so you can replace the shocks and springs with a solid steel tube. That will get rid of the suspension. I think you'll find that you miss it after you try no suspension. It's REALLY rough.

 

[Revolt]

I might try that out and see how it go's man. Thanks.

 

[woncamaro]

Yerf dog went out of business a few years back so parts are getting harder to come by. That particular kart should have the adjustable coil over socks. There is a cam at the top of all 4 shocks which can be turned to apply more pressure to the suspension and reduce the slack. Those shocks are not the best to begin with although and really weren't designed to hold much more than a couple 100 lb kids. The tecumseh motors can be modified by replacing the valve springs with tougher aftermarket srpings. This will help the engine produce more rpms by stopping the valves from floating which means more top speed. A straight exhaust pipe helps as well, but the yerf dog frame runs directly in front of the muffler so a pipe elbow will probably be needed as well as the fact that the tecumseh motors on those karts do not have thread in the block like a briggs motor and an exhaust flange will need to be welded to the end of the pipe in order to bolt it to the motor. Drill out the air jet a bit and replace the fuel jet with one of a 1/2 horsepower larger tecumseh. Also, bypass the govenor if you haven't already. I managed to get 45 mph out of my single seater yerf dog by doing all this work to a 5.5 tecumseh.

 

[Revolt]

I wanna take the governor off but i'm not sure how or if its safe.. anybody know?

 

[modelengineer]

It's safe. Do it.

 

[Revolt]

Do you know how?

 

[modelengineer]

When I did it I just took off EVERYTHING (all the linkages) which were attached to the carb, and then attached the return spring and throttle cable to the carb butterfly.
However this was on a vane type governor and not the internal centrifugal type.