klx140l low pipe

[IacobucciB]

Hey all, just a few questions about a Flat track/supermoto setup for a KLX140L Monster edition bike. I've ordered a K&N pod filter (Part no. R-1030), Ballistic evo2 battery, and KX100 forks sprung for adult riders. I have a set of Trail wing 40s tires for the stock rims. Thinking of running a low pipe to my powercore slip-on, but no headers are available. I'm thinking of buying a length of pipe, then bending it to run the downtube and bottom of the frame, then welding it to the stock flanges, then fabricating a bracket to hold the powercore low, around the swingarm area. Also going to run a 100-102 main in the carb. Will this affect the bike's power compared to the stock high-pipe? Just doing this as a mini project so I can fool with a little bike again.

 

[Go Big Red]

The curve and length of the pipe will affect your power curve, specifically where a portion of the torque will be applied. I shorter more restrictive pipe will generally, but not always depending on other factors, shift the torque curve to the bottom end. A shorter more free flowing pipe will shift it to the top.

So, it really depends on where you want your power. I do understand that shifting some weight down will help with handling in the corners, but not sure it will help much with power since there isnt a lot to start with in the first place. Basically, you are trailblazing with this project and may have to experiment a little to squeeze out what you can with a header mod. The aftermarket air filter and jetting will help. Drilling out some holes in the airbox and removing the snorkle are also a must. Other than that, your next step would be finding a cam, higher compression piston and a bigger carb.

[IacobucciB]

The curve and length of the pipe will affect your power curve, specifically where a portion of the torque will be applied. I shorter more restrictive pipe will generally, but not always depending on other factors, shift the torque curve to the bottom end. A shorter more free flowing pipe will shift it to the top.

So, it really depends on where you want your power. I do understand that shifting some weight down will help with handling in the corners, but not sure it will help much with power since there isnt a lot to start with in the first place. Basically, you are trailblazing with this project and may have to experiment a little to squeeze out what you can with a header mod. The aftermarket air filter and jetting will help. Drilling out some holes in the airbox and removing the snorkle are also a must. Other than that, your next step would be finding a cam, higher compression piston and a bigger carb.

I'd mostly be running the bike from 7000 rpm to the rev limiter. I am doing an airbox delete and running a ballistic lithium battery to cut down on weight, mostly to just shift the bike's CG lower. The header will probably be cut an inch or two before the footpeg, replicating the shape and bend of the frame downtube to the engine cradle. I have a VM26ss carb sitting in my parts cabinet, and I'll probably machine a different intake tract to accept the new flange. I have a local guy in my phonebook who can probably port the head. I want to keep the stock bore, so I'll probably just go with a BBR or billet piston. He works mostly with small XRs, but for the right price, I'm sure he'd help me out. Last, I'd probably send my cam to Web to be hard welded to a new grind, and look around for a set of valve springs. All the motor work will probably go over the winter. Something to keep me busy on the weekends.

[Go Big Red]

Sounds like a good little project. Are you also converting the chain and sprokets to 520? Not sure if there is one out there but a heavy duty clutch may aslo be an option.