KLX140L Build
By Jerry Matta

New KLX140L build. I'm going to build a fairly cheap and reliable bike that would be great for any type of mini fun. The suspension came with it, so that is taken care of. At least I hope. I haven't tried it yet. But its going to be a simple build with the following: Exhaust, carb, cam, 170cc kit, CDI, Pegs, graphics, powder coated frame. That's it. Very Basic and straightforward.
UPDATE:
I ordered a Big Bore Kit, pegs, CDI, small intake, and exhaust. It's coming from Indonesia, so we'll see how long it takes. But, everything cost me just about $100 more than a Yoshimura exhaust.
*****I ordered it on June 27, it got here by July 3. That is crazy fast!!!
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July 4th update.
Stock pipe is 6 lbs 4 oz
Norifumi Pipe is 4 lbs 12 oz.
Upon initial start up, it started instantly, which it didn't before.
Tomorrow I'll ride it around my street and field to see if I can tell a difference. After that, I'll swap out the CDI, then start on swapping out different carbs.
For the carb test, I have two for the stock set-up: a 200x carb and a KX65 carb. When I get the 170cc kit installed, I'll test a XR200 carb and a PWK KX100 carb.
*Note: Carb my have been richined up before I bought it.
Pipe with *stock everything. Cold starts much quicker. You can barely hit the button and it starts up. Seems to pull through the gears better. There's a difference but not night and day.
Next: CDI
The CDI can be swapped out without removing anything, which is nice. However, it's bigger than the original one, so a bracket or something needs to be made. How did it work? It's hard to tell, it didn't rev out any different. Maybe it pulled through the gears a bit stronger, kinda like a street bike, but I can't make that claim.
With the KX65 carb, it did help it mainly on the bottom and mid. I ran a stock 25 pilot, stock needle , and a 150 main. (stock is 180). I used a bigger intake manifold ($12 from indonesia), and a 1 1/2" coupler from Lowes. I also, used the end of a TTR125 airboot over the carb, and a machine aluminum piece that goes inside the end of the KLX airboot to keep it from squishing, with the rubber coupler over everything with a couple hose clamps.
**Update: The bike is torn down to powder coat the frame. At the same time, I'm installing a 170cc big bore, cam, roller rockers, and a PWK 28 carb.
NOTE: The Cam bolt is a LEFT HAND THREAD. That would've been nice to know.

You need a long rotary file to cut down the bump in the head.

You can see the bump at the back of the head.

I took about half or more off.
Update:
With 170cc kit, cam, pipe, cdi, I've been trying to get a number of carbs to work. I've tried a PWK 28, XR200 carb, KX65 carb, and the only carb I can get to run is the stock carb with a 105 main and a 40 pilot. I don't know what the deal is. I think it's the nearly three inch intake track on this. There's not much of a way around it, since the fuel tank is cut away towards the rear part and drops down in the front thanks to the perimeter frame. I did or a normal short spigot manifold just to test it out. Those are a pain too. I think it's a Amal to Mikuni conversion manifold. JetRus and Sudco want $80 for them, but I think I found one on ebay for $13 plus shipping. I hope it's the right size.
Update: PWK28
Because of the horrible stock airboot, I went to a pod filter. (I'm not a pod fan)
Here is the final jetting:
Temps in the 90's, not much humidy
42 pilot
clip middle
100 main
1 1/4 airscrew
Revs bottom to top really good and starts.
I am going to have Dave Miller make me a stainless airboot. Around a 3" - 2". That's about 400% increase in surface area over the stock one, which is only 1.4" at the airbox.
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Latest Update: Dave Miller passed away. RIP
This bike got stolen, but about 4 months later, I got it back.



