[keeperofthecode]

I got a 2003 300EX that my nephew races at the mud drags. It's never been a dominating ATV at the track but he's usually at least pretty close to the top guys. Now there is a new Cannondale 440 that has had a ton of work done on it that has been leaving him in the dust. I'd like to try and get him at least somewhat back in the game if possible. The cannondal runs pretty regular 4 sec. runs and my nephew is running 6 sec runs.

I bought it used so I'm not 100% positive but I think it is stock except for the DG exhaust. The track is 200' long and the mud is usually about a foot deep. It has Swamp Fox tires on the rear which seem to get him through pretty good. I bought some paddle tires for it but they actually slowed it down so we went back to the swamp foxes. The 300EX launches hard and keeps up till about half track which is where the cannandale leaves him behind. The 300EX is pretty much topped out in third gear when he's at 3/4 track, but he has to ride it out cause if he goes to fourth it bogs down and he loses time. I think we can afford to lose bottom end to keep third gear pulling all the way through. I'm just not sure what mods I can make to achieve this. Or maybe we just need more power. What do you guys think? Should I be modding this thing to try and catch up or should I be looking at a 450 or something? Thanks for your help.

 

[elmerkit]

How about upgrading its intake, ignition and a full system. then if still you need speed go for stage 2 port and polish cams etc.

 

[keeperofthecode]

my uncle who builds race go kart engines says I need to start with a hotter plug and bigger carb. I'm just not sure what's out there reasonable or even where to look. Where does eveyone else go for performance parts fot ATVs? Also, is there a recomended CDI box? I'm assuming that's what i need to upgrade ignition. Also, I have no idea where to look at carbs or jet kits. Sorry to be asking so many questions.

 

[Bickford]

hey there differents types of carb u can put a 400ex carb on a 300ex or edle brock has a carb out for a 300ex

my 300ex has for updates
full fmf power core 4 pipe and header
stage 1 carb kit
K&N air filter
clutch kit

i just order
wisco piston
stage 1 cam
pro com cdi box
AMR RACING PERFORMANCE IGNITION COIL
i went to a 7 for my plug

u can find most of the stuff from ebay its the cheaps place i found around

 

[keeperofthecode]

Anyone have experience with both the 400ex carb and the edelbrock. 400ex carbs run $100 and the edelbrock is just under $400, it'd be nice to know if that 400ex carb will give a close gain without the pricetag.

 

[Bickford]

the 400ex carb should give u more gas and a better respons there is a guy on here that knows more about the 400ex carb then i do

 

[Helmut]

Moose has a 400EX carb on his 250X.

 

[trx450r]

i hav 95 300ex and i was thinking about runnin mine mud races.. and i was thinking about those tires... there r a bunch of wicked 450r i will have to race aginist..i would also like to no how to get alittle more out of mine

 

[keeperofthecode]

So, I've been reading up on motor swaps since my 94 300ex has the motor out at the moment. Somenody mentioned a busa motor but a quick google yielded no info on swapping into a 300ex. Let me know if you know where there is some info. However I did find several posts saying that if your going to swap an engine a 250r 2-stroke is the most bang for your buck. Anybody have any thoughts on that?