How to get more power Fire Fox 620

[Recon_Kart]

Hi everyone,

I'm new to this forum and am hoping to get some great info!

I recently picked up a Fire Fox 620 with a stock Mitsubishi 6HP GX600. The Kart also has a torque converter which is stock (not sure the specs at the moment). I can get maybe 28 mph. My main concern is power, not speed. What can I do to this engine to get more power. I would like to be able to crawl through thick soft mud, water, etc. This is a fun kart, but in it's current state I cannot get through 2" mud with out getting stuck, and when I get stuck, I'm not buried or spinning. It seems it doesn't have enough power to propel me, I don't even think the sprocket is spinning, even with full throttle. I don't have the vastest knowledge when it comes to modifications etc...Looking for any advise you all can give me. Thanks!

 

[OzFab]

What you need is torque. If you're not concerned about top speed, the obvious answer is to regear so you top speed is lower, thus increasing acceleration potential.

Apart from that, you could get a hi flow air filter & exhaust...

Welcome to the forum

 

[Recon_Kart]

Now does how much slack in there is in the chain play a role in why the sprocket isn't turning? I think I will have to open up the TC to see how that's functioning. I was planning on installing a hi flow air filter. Do you think a hi performance carb will also help give more power? I've also been thinking about removing the governor, now I'm a bit nervous about doing that because I do not like the thought of the engine running on excessive rpms...any thoughts on that?

 

[Recon_Kart]

Also, I'm not concerned about gaining more speed, but I don't want to lose the speed I currently have. Is there a way to increase the torque while maintaining the current top speed. Or at that point would I be looking to upgrade to a bigger engine? If so, any recommendations on higher powered engines without needing to mod the motor mounts in any way? Thanks.

 

[OzFab]

Removing the governor will only increase max RPM &, therefore, increase top speed; it will not effect torque either way.

If you leave the stock valve springs intact, they will start to bounce at around 5000rpm, giving you a new max RPM limit...

There's an old saying, "the better an engine breathes, the better it will perform". A hi flow air filter will only be effective if you also use a hi flow exhaust; breathing in is only effective if it can breathe out!

A performance carb may or may not help, as rejetting the existing carb may or may not help; there's no point letting the engine breathe better if it's drowning.

The chain should have about 3/8" of movement but, chain tension shouldn't play too large a role in overall performance

 

[Recon_Kart]

Any recommendations for hi flow intake / exhaust - what brands / models I should go for, or that will work good for my Mitsubishi 6hp GX 600?

 

[Recon_Kart]

Also, I removed the cover for the intake, and the bottom portion of the air filter was soaked with gas. Any ideas of what is causing this?

 

[B man]

removing the governor could help. higher RPM may not always mean torque. but torque is varied by the RPM so it may have more torque at the higher RPM.

 

[OzFab]

Possible but, unlikely. Most industrial engines are governed at 3600rpm because they've already reached their torque peak by then (not to be confused with maximum)