Kawasaki K-TRIC Carb Information

*Not really KLX related, but I am posting this here as an archive*



Doing some digging around the net i found some interesting stuff a guy did a few years ago mapping the ignition curves of the CDI on a ZRX1100. Yes i know its not exactely the same as my 2002 ZX-6R, but the K-TRIC system appears to work in the same way on all of Kawi's bikes.

Thanks to Sean Stasiak for all this information and to Jake from Kawiforums for bringing the idea to my attention. I tried to send Sean an email to see if he had any other relevant information, but it was returned as it appears the email in the .pdf is no longer valid.


This first image shows a sample of the 3D timing map the CDI uses.

The second image shows the operation of the TPS unit. Basically more throttle = more voltage to the CDI which translates into more timing advance.

The third is a scan showing the text of the manual describing the K-TRIC operation and its default protection.

Now heres where things get interesting.

From what I gather the CDI input for the TPS operates in a range of 0-5v. The J model service manual states that a properly adjusted TPS shows .95v - 4.15v (lowest idle and highest WOT reading respectively). The ZRX1100 manual states .9v - 4.26v while not exactly the same, is pretty close. More on what this has to do with anything in a minute.

Here is a .pdf showing the ZRX1100 default ignition map with the TPS unplugged.

http://gstasiak.home.bresnan.net/DefaultAdvMap.pdf


As you can see the timing map tops out with around 37 or so degrees of advance.

Now here is the high res mapping of how the CDI interprets the readings from the TPS. (You'll need Excel to open and view the spreadsheet)

http://gstasiak.home.bresnan.net/Hi-...%20Mapping.zip


Looking at the spreadsheet you can see that Sean's TPS topped out at a voltage reading of 4.13v resulting in a maximum advance of 35.52 degrees. Now this may not seem signifigant, thats only a 1.48 degree difference in advance. However what this implies is that even with a properly adjusted TPS the CDI will never reach full advance even at WOT, not to mention how this could affect the TPS adjusted timing curve. Unplugging the TPS defaults the CDI to the "safe" timing map and also results in maximum timing advance that the CDI is capable of.

FWIW I've had mine unplugged for about 3 years now and I feel there is a difference in power output from my 2002 ZX-6R. I've seen no indication of any kinds of problems from running the TPS unplugged.  Your results may vary and i take no responsibility for any damage that may be caused from running with the TPS disconnected.

Installing a lightweight Flywheel

Since my bike is now a full time supermoto, I wanted a bit quicker throttle response and faster spin-up for the engine. I was less concerned with low end grunt like was needed for off-road technical trails when the bike was equipped with dirt wheels and tires. I sent a flywheel I purchased off of ebay to Cycle Pro in NJ to have it shaved down and lightened by 10%. Turn around was about a week and a half.

 To swap a flywheel the steps are as follows-

Drain engine oil
Remove Sprocket cover and case saver

 Once that is done you should be looking at this (i had my chain removed for cleaning, you should be able to move it out of the way since the back wheel will be coming off but more on that later) -

Next you will need to remove the three 8mm bolts from the starter gear cover which sits above the alternator cover.

There will be two additional bolts inside of here that will need to be removed in addition to the 8mm bolts around the periphery of the alternator cover.  The starter gear will need to be removed, it should just slide out.

Once that is done you should be able to pry the alternator cover off with some wiggling.  There is an o-ring on the starter that can make this a bit tricky as well as possible gasket stickiness. 

When the cover is off you should be looking at this but note that there will be an additional gear set that will interface with the flywheel gear (mine is removed in this pic, it sits in the bushing hole at the top right of the flywheel).  I have heard you can remove this gear with the flywheel still installed but I was unable to, not a big deal. Be sure to check this bushing for damage as they have been known to wear out prematurely (not common however). 

Now we will need a way to keep the engine from rotating while we remove the bolt holding the flywheel on.  I used a chain clamp.  

Once the bolt is free we need a method of pressing the flywheel off the crank.  You can use a fancy tool for this but I used the rear axle since it's the right size and thread. You may need to re-position your flywheel holding apparatus to keep the engine from turning.  

Once you have the old flywheel off make sure your starter ring and shim are in proper orientation as well as the key for the crank and you can install your lightened flywheel.  Getting it back on can take a few tries but since it is keyed it's impossible to put on the wrong way (unless you forget to use the key).  Don't forget to put your starter gear back into its bushing like I did the first time, luckily I didn't have the bolt torqued back down.

Tighten the flywheel retaining bolt to 88.5 ft lbs.

I was able to reuse my original gaskets and have not detected any oil leaks, but it wouldn't be a bad idea to have new gaskets on hand in case they tear while taking things apart.  Reinstall everything in the reverse order and refill the crankcase with fresh oil and enjoy your new, quicker revving KLX !!!

Converting S front brake to SF

Well, luck would have it that i came across a great deal from a forum member over at the supermoto junkie forums who had a complete front brake setup for CHEAP.  So i snatched it up just to complete that last little detail on my converted S model.  Below is a quick overview and photo follow along of the install -

First get your bike up on a stable platform to remove the front tire.  I have a couple of moto stands from harbor freight that work pretty good.

Next, move around to the front of the bike and loosen the 10mm fork clamps for the axle, and then loosen the axle nut with 17mm and 19mm sockets or wrenches.

Slide the axle out from the left side of the bike and slide the wheel out taking care to not lose the spacer on the right side (rotor side) of the wheel and sliding the rotor from between the brake pads on the front caliper.

Set the wheel spacer, axle and axle nut aside and set your wheel down on a flat surface to work on removing the rotor bolts.  I like to use a large broken down cardboard box to prevent scratching of the wheel.  Remove the rotor bolts with a 6mm allen wrench. To break the bolts loose I used a 3/8 drive ratchet and allen socket since they were so tight.

Once the bolts are removed you should be able to lift the rotor off the wheel.  The rotor cushion foam piece will probably stick to the rotor and come with it.  I re-used mine, i believe its intended function is to reduce brake noise.  Put the new rotor on and line up the bolt holes, then replace and tighten the rotor bolts.

You can see the size difference between the S and SF rotors.  Will this translate into better braking ? Only one way to find out.

Now we move on to the caliper bracket that will move the brake caliper farther away from the wheel to allow clearance for the larger rotor.

To install this, we first need to remove the bolt that holds the brake line bracket so we can get that out of the way to give us some more workroom.  Its a 10mm IIRC.

With that out of the way, loosen the caliper retention bolt on the inside of caliper.  This will allow us to remove the caliper from the bracket later and is very tight, so i recommend doing this first while everything else is still bolted to the bike.  You don't need to remove it all the way, just break it loose.

Next, remove the caliper bracket mounting bolts, these are 6mm allen, same size as the rotor bolts.  I recommend 3/8 drive ratchet and allen socket for this as well.

With those two bolts removed the caliper and bracket should dismount from the fork.  Now you can remove the caliper retaining bolt from the back of the caliper and slide the caliper from the bracket.  I had to use a bit of propane torch and a punch to tap the retaining bolt from the bracket due to a little bit of corrosion.  I don't have detailed pictures of this step but its easy enough to figure out, but may take a little wiggling and finagling to convince the caliper to slide from the bracket.

there is a small post bolted to the bracket that slides into a rubber boot on the caliper (middle of the bracket in the pic below), this stays on the bracket where as the other rubber booted bolt stays on the caliper (the D shaped hole on the upper left of the pic below).

Now install the caliper to the new bracket taking care to ensure the retaining bolt is orientated properly into the D shaped hole and that the caliper post on the bracket is installed correctly into the rubber boot of the caliper.  this again may take some jiggling and finagling.  Once that is done you can re-install the caliper retaining nut and put the bracket and caliper back onto the fork.

Re-tighten the two 6mm bracket bolts to the fork and then re-torque the caliper retaining nut. Replace and tighten the brake line holder bracket and you are done with the caliper.

Slide the wheel back into place taking care to ensure the spacer is reinstalled correctly on the rotor side of the wheel.and the speedo drive is reinstalled correctly on the other side.  Slide the axle back into place and retighten the axle nut to 65 ft-lbs.

Now stand back and admire you new fully supermotoed KLX250S.

Now, i really don't think i've noticed any improved braking performance from the larger rotor, and to be perfectly honest if I hadn't gotten a good price for everything i wouldn't have bothered.  Now, if you are taking your bike to the track and running it hard, it might be a different story.  BUT for my use so far on the street, i can't tell a difference.

Thanks.

KLX250S Custom Stock Exhaust Mods

Finally got around to finishing up my stock exhaust mods.
I used a exhaust tip from a KX400 ATV and hacked it down to fit, blowtorched the straw out of the stock exhaust and with alot of paitence and a keen eye for detail, I prevailed ;)

Heres the hole that i cut with the torch and then dremeled out to give a snug fit to the tip.

Heres the tip cut down, forgot to take pics of the before, but it was quite a bit larger in diameter.

And heres the 90% finished product (gotta rivet it on).

I think it sounds really good, not much louder than stock but with a nice mellow throaty thumper sound when you get on it. I'll try to get a video so you can hear the sound when its not so windy outside. Personally i think it came out pretty good for a hack job using only a blowtorch, angle grinder and a bench grinder :D