I purchased a JD Jet Kit for my TRX 450R, I am new at jetting and carbrator adjusting. I put in the recommended jet for my elevation, and ran the quad it ran fine for a while but now my spark plug fouls out all the time maybe once a day. Most people have told me that this means I am running way to rich (as in too much gas to the Carb) I dont know how to adjust it and I am sure as hell not going to pay Hillsboro Motosport $115.00 to adjust my carb. Can anyone on here tell me how to adjust my carb?

Thanks for your help,

Ken

No mods really I mean I got a K&N Air filter on it and yes the air box is off. (well and plus the jets)

How do you know what is right? (when adjusting the Carb)

 

Need more info,what mods do you have,pipe, airbox lid off,cut, etc. and what size jets are you running? and I'd be happy to help

 

under your carb theirs a screw take a flatt head screw driver and you can turn it i put a dyno jet kit in my rancher had to adjust the fuel mix to get it just right. Im taking a hit on top speed for more low end power.

 

My friend had the same problem with his z. N ot fouling the plug bu running too rich. Go down to a smaller main jet.

 

What did your spark plug look like?

 

Spark plug is black and has burnt residue on it. I burn it with a lighter and rub it off and put it back in fires right up.

Which direction do i turn the flat head screw?

 

You still haven't told us what jet sizes you put in. Tell us the whole story, the more detail the better. I would NOT touch the air/fuel screw yet until you tell us what jetting you have. You have the stock exhaust untouched right?? What do the instructions say on the jet kit? I am surprised they give you a jetting estimate for no air box lid only. Also, what style of jets does this kit give you, are they long hex style?

 

ya more info is needed but if its a dyno mine said turn it until fuel screw seats then turn it out 3 1/2 turns.

 

So here is the details.....

I replaced the stock jet with a Keihin 185 main Jet
I replaced the stock Needle Clip with the Keihin needle clip
I have a K&N Air Filter
I am running it completely without the air box lid

The Jetting kit gives some direction on installation but nothing about Carb adjustments.

Let me know if you guys need any more information.

Thanks alot,

Ken

 

Sounds way too rich on the main, what made you want choose a 185? I would start at about a 160 or so with a totally stock muffler and check your plug.

Did you replace the needle also, what do you mean by you just replaced the clip? And if you did put in a new needle what clip position did you put it at?

Also, I am assuming you have a 04 or 05 trx450r?