New to me KLX 140L

[mabdcmb]

Hey all.  Just picked up an '09 140L yesterday for my son.

I did a couple laps in the yard. It seems like there is a bit of a gap in power from 1st to 2nd gear.  For the type of riding we plan to do, I think the bike would benefit from a smaller front or larger rear sprocket.  We typically do tight, technical trails.  Not much wide open blasting.

I see that JT has a few options.  I was considering a 12T front.  Has anyone fitted one on the 140L?  I was curious if it caused excessive wear on chain slider on the swingarm or anything?   

Anyone have some advise on what gearing is working for them on tight woods riding?  Is 12/52 too much?

[S.O.A.N.Z]

14 T stock on it now ?

 

 

[Timrumble]

We had 13/52 on my boys 2010 140L. It worked better, but we did a few other mods to try to get more out of it.It was a awesome bike or him to learn on.

[mabdcmb]

17 hours ago, S.O.A.N.Z said:

14 T stock on it now ?

 

 

No, 13/51 is stock on the 140L. 

I pulled the trigger on new parts this AM.  Looking to get the bike ready for its first weekend trip.  We going out few a few days over memorial day.  I got 13/52.  I figure we'll see how it does during the trip.  If we feel the need to lower the gearing some more I'll but the 12T off amazon.  I see JT front sprockets are only about $9 with free shipping on there.

I ordered up some maintenance items like tires, sprockets, chain, brake pads, fork oil, oil filter and air filter.  I figure we will turn some wrenches together and get the thing all serviced and ready to go since its its new to me.  This way we have a good baseline.

 

[mabdcmb]

I figured its time to do some maintenace.

 

Started with an oil and oil filter change.

 

Installed a new Uni air filter. The PO seemed to not know how to properly install one. Cleaned up the airbox and the overflow.

 

Changed the fork oil. Id bet that stuff was original. Looked like black syrup and stunk.

 

Greased steering stem bearings. They were fairly dry.

 

Checked front braked pads. Not sure if they were the originals but they were stockers in great shape.

 

Changed front brake fluid. It looked like strong coffee.

 

Checked front wheel bearings. They felt good. Pulled the front tire and lubed up the spokes and then tightened them all up. Finished it off by installing a new bridgestone battlecross x30

 

Checked out the carb. It was pretty clean. Jets are original equipment. The air cutoff diaphragm looked wrinkled up. I have a new one on order.

 

Checked the valves. They were on the loose side of the spec so i let them be. I figure they will only get tighter in time.

 

Changed the spark plug.

 

Found out we have a BBR exhaust on the bike. I tightened up the mounting hardware on it and and sealed the pipe to muffler joint with ultra copper.

 

Will be working my way back to the rear wheel soon. Im going to grease the swingarm linkage, change rear brake fluid, check the pads, wheel bearings, tighten spokes, and install a X30 tire.

 

Hopefully that will cover things for awhile.

 

 

 

 

[mabdcmb]

Almost done for now.

I greased the linkage, new chain, new sprockets, new rear tire, tube, and tightened up the rear spokes.

Wish I could find aftermarket plastics.  These ones are a little rough.  I did some work on them to keep them bolted on but they don't look too good.

Fired it up and noticed the bike acts different.  Before, no choke required on startup.  Now it is.  I didn't change jets.  I think its kind of odd...  Need to fine tune the AF screw

Its now running a 12T/52T combo.  JT sprockets and chain.  Seems like it will be a good combo for tight woods.

 

[mtgraves]

For the jetting with your current setup a 100 main and a 40 slow works really well. 

[mabdcmb]

24 minutes ago, mtgraves said:

For the jetting with your current setup a 100 main and a 40 slow works really well. 

I've been doing some reading and that is definitely the common formula on this, and other forums, and the Jetsrus website.

My KLX had stock jets, BBR full exhaust and a twin air filter that was improperly installed when I tore into it.  It started without choke when cold.  After a carb clean, air box clean, new uni filter and new plug it seems to react more like I expected.  The original plug looked rich.  We'll see how it looks after we put a couple pulls on it after the changes. 

[mabdcmb]

Just a little update. The bike performed perfectly over a 4 day weekend of riding.

Started easy with the stock jetting and ran clean.

The gearing change seems great for our riding. Mainly trails but able to get up in the mid 40mph range without issue.

He busted the clutch lever on day 2. Someone un our group had a full ASV lever and perch assembly. I installed that and just left the clutch switch hanging. The ASV lever seems to put the engagement zone in a much more natural position so that turned out to be a plus.

[Phoenix27101]

Where's the air fuel screw on these? I've found the idle but cant find the af screw?