So I bought a brand new KLX last yr, and I have to say my main reasons for this choice was seat height, and I think its a great looking bike.
I ride 90% trails so 2 days into my ownership I took it back to the dealer and changed tires, (Trackmaster II) had them install complete FMF, (with Powerbomb) they did the airbox mod and jetted, drop to 13 tooth front sprocket and also did the coil groundwire update under warranty as I was getting the flatspot around the 6000 rpm.
This totally changed the bike, and I was pretty happy with the results, but of course i'm now feeling the need for more power.
My first instict was to trade it in for a WR, but I dont want to get into lowering kits, and I now have too much $ invested into it. So my obvious next move is the BB 351 kit, it sounds like most, or all here on this forum that have installed it are happy with the results, one question I do have is.......has anyone ported/polished the intakes/exhaust?...... maybe even just cleaned it up a bit? .........I always puttered with 2 stroke engines in the past and used get some great results, just curious as to whether I should bother getting out the dremmel??

thanks,
Ed

 

Porting and polish couldn't hurt,probably just flow a little better on top end.
I guess you have fuel injection. Is anyone making larger throttle bodies? What size is your throttle body?
just a thought.
marc

 

Nope, I have the carb.

 

At some point, or honestly just about any point, you'll find a Mikuni 36mm pumper carb to be a worthy addition...especially if you increase the bore to any degree. The throttle response, acceleration, and top end are noticeably increased. The TM36-68 is just about a bolt-on as far as installation.

 

I have the 351 kit and I did some port match/cleanup while I had it apart. The added displacement made a huge difference and I have recently added the 36mm pumper-it improved throttle response. If I do any more it will probably be to add some Webcams-the motor signs off at about 8500 so it really could benefit from some more cam. But be forewarned-these mods can be addictive...

 

have you even done the Marcelino mod yet
i was very very impressed by how it woke up the KLX my B/F has a wr250f
and this mod with the pipe and jetting brings it very close to the wr250f
the WR250f is no YZ but is still s strong running bike


BTW what jet did they put in did they replace the needle and all or just the jet
what rear sprocket did the put on also ???

i found i have more from the 132 then the 128 that was FMF setup

I would give the cam mod a try first then over the winter do the 351 BB kit*
that is what is in my plans as well

 

Is the coil ground wire a common problem?

 

This 100%, I have had this work done to mine..Well it was done when I bought it I just validated the workmanship! But yes, this setup REALLY helps. A few guys at the MX track were surprised by the little KLX's power considering it's a "duelsport" and not a offroad only machine like theres..haha

 

Sorry, it's actually a rectifier ground issue, there is a thread about this somewhere on this forum.

 

Thanks For all the input guys, the 351 for sure, and I guess I might as well get the pumper carb while I'm at it. Also going to read up a little more into the marcelino cam mod.

Ed