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Only $10 for all 2026 SX, MX, and SMX series.
Certainly way better then 187 stock.
I could be wrong but after I started playing with the K5 cylinders I came to the conclusion that the original design was 191.
Like most of their MX engines Kawi likes to leave a little in reserve.
And why not, most guys are not using the full potential of the stock engine.
If Honda or anyone else came out with something faster, all KAwi needed to do was bump it up a bit.
You said that Millennium did your head?
Do you know what CC they used or, what compression ratio they went for?
A lot of guys don't realize that when they raise the port timing, they are lowering the trapt volume and are actually lowering the compression ratio.
Of course, if Tom Morgan had his mits on it while it was at millennium he knows all that..
Stock squish is around .070" so your head was at least shaved a bit.
High temp RTV is ok but it can come out easier then case sealant.. But likely you'll be ok..
I would have "kissed" the gasket area at least, but the my lathe Jig works off the spark plug hole being concentric with the combustion diameter. I'll make a jig to fit the head in proper later and tweak this thing.
What numbers do you recommend max torque and smooth power? Long term goal is to smooth this thing out like a 450, luggable power.
I need more info to get you what you need.
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Luxon 4-Post Bar Mounts
$189.95 - $239.95
Have been fiddle farting around with this adapter plate for quite a while. I've seen a bunch of ways of doing it, but came across this 450 cover for free and the bolt pattern worked out perfect.
Turned out pretty good.
Rebuilt shock today. Race tech gold valve and bladder cap.
Motor in but waiting on few things to button it up.
Hydro clutch in and fitted. Feels good.
Made great strides last week or two. Get this thing tuned in, work some bugs out and it will be track bound very soon. Can't wait.
The bike is looking good...
This project created some challenges. Never submit. Ride day tomorrow.
Well first time on a 500. Very very smooth power, I like it.
Pros:
Heard these things don't turn. Well this one does.
Think I knocked it out the park with the suspension set up. Works awesome.
Brakes, brembos are unreal.
Hydraulic clutch
The seat, its like a couch,
Sort shifting is fun, very 4 stroke like
Quiet, but man a 500 sounds good.
Cons:
STARTING, even with the de comp on the head it sucks and very inconsistent, I have to get this better or it will never see a race unfortunately. No way I could start this thing on the gate. Its not good. Kick it 7 times, then it will back fire/pop, then about 5 kicks later it will fire up and your heart rate is 189bpm.
My jetting is off, hope the starting improves once this carb is tuned in better.
Even though the seat is nice, very small sweat spot, the tank will rack your nuts or the fender will slap that ass.
Big thanks to Mike Weir, really appreciate the help figuring out some issues!!
Especially if you run the Emig dog bones which put a bit more weight on the front end and help protect against rear wheel hop over nasty whoops.
In fact, one of the things that Motocross Action Magazine commented about Sean Collier's KX500 we built was that they were shocked at how well the front end hooked up. Put it on a line around a corner and it sticks.
Starting Jetting for a relatively stock KX500 at 0-1000 ft elevation
55 Pilot
170 Main
Stock needle at the second position from the top.
Air screw 1.5-2 turns out.
You may be able to drop to a 168 main but watch your plug...
Nice job on the build...
I need to get mine running again...
Great thread!!
Sandblaster, when you say "stock needle", which needle do you mean?
I see a dozen options listed?
https://www.partzilla.com/catalog/kawasaki/motorcycle/2003/kx500-kx500-e15/carburetor
Thoughts on the "CEN" needle?
Having issues with cold starts, but it starts fine when warm.
Also noticing a detonation type, popping issue at WFO in 4th gear late in my motos.
Was going to inspect my reeds as I noticed in the Eric Gorr info, that could be the cause?
Or maybe it's fuel related?
Current fuel set up is C12 @ 36:1 with 927, but I'm hearing that I may be too lean with that much oil, so I was going to try 50:1 this weekend and maybe cut the C12 with 91 pump at 50/50.
Thank you!
16009B NEEDLE-JET,N82M 16009-1580 Is stock.
Note: all the other needles listed have the following: (OPTION) after the numbers.
Hard to start when cold?
It can be several things but if it is jetting related than it says that your pilot jet is too lean.
Thoughts on the "CEN" needle?
Never tried one in a KX500
Also noticing a detonation type, popping issue at WFO in 4th gear late in my motos.
Was going to inspect my reeds as I noticed in the Eric Gorr info, that could be the cause?
Potentially but it sounds like jetting or oil to fuel ratio.
If your reeds have more than 100 hours on them they probably need to be replaced.
You can tell by pulling your seat off, starting the bike, and rev the motor.
Put your hand into the air box while revving.
Can you feel a draft?
If so replace those reeds.
Use a V-Force 2 on the "Low tension setting"
It's good for 3-4 HP on the dyno at the rear wheel over a RAD valve.
If you can't find a VF-2 let me know and I'll get you a new one.
Or maybe it's fuel related?
Current fuel set up is C12 @ 36:1 with 927, but I'm hearing that I may be too lean with that much oil, so I was going to try 50:1 this weekend and maybe cut the C12 with 91 pump at 50/50.
36:1 was done years back due to the lower quality of oils available.
Today, follow the instructions that each manufacture recommends for it's brand of oil.
927 is a good oil but can separate from the fuel easier than others.
Just be sure to shake well, than shake again to make sure it is fully mixed.
Throw out old fuel.
Check with the manufacture for recommend ratios at their website.
I run Motul 800 at 50:1 but for trail riding they recommend 66:1.
Other oil manufactures recommend up to 100:1
And your right, more oil per any volume of fuel means less fuel going through the jets...
Per the same amount of air that means a leaner mixture.
If your bike is stock you need less C12.
50/50 is a good place to start.
But get your jetting sorted first.
Once that is done, start experimenting with how much c12 you run.
You don't want to run any more than is required to keep your engine from detonating.
Note: all the other needles listed have the following: (OPTION) after the numbers.
Hard to start when cold?
It can be several things but if it is jetting related than it says that your pilot jet is too lean. Running a 58 pilot.
Thoughts on the "CEN" needle?
Never tried one in a KX500 Will try an N82M needle.
Also noticing a detonation type, popping issue at WFO in 4th gear late in my motos.
Was going to inspect my reeds as I noticed in the Eric Gorr info, that could be the cause?
Potentially but it sounds like jetting or oil to fuel ratio.
If your reeds have more than 100 hours on them they probably need to be replaced.
You can tell by pulling your seat off, starting the bike, and rev the motor.
Put your hand into the air box while revving.
Can you feel a draft?
If so replace those reeds.
Use a V-Force 2 on the "Low tension setting"
It's good for 3-4 HP on the dyno at the rear wheel over a RAD valve.
If you can't find a VF-2 let me know and I'll get you a new one. Thank you, I have a VF3 now, is that not as good as a VF2?
Or maybe it's fuel related?
Current fuel set up is C12 @ 36:1 with 927, but I'm hearing that I may be too lean with that much oil, so I was going to try 50:1 this weekend and maybe cut the C12 with 91 pump at 50/50.
36:1 was done years back due to the lower quality of oils available.
Today, follow the instructions that each manufacture recommends for it's brand of oil.
927 is a good oil but can separate from the fuel easier than others.
Just be sure to shake well, than shake again to make sure it is fully mixed.
Throw out old fuel.
Check with the manufacture for recommend ratios at their website.
I run Motul 800 at 50:1 but for trail riding they recommend 66:1.
Other oil manufactures recommend up to 100:1 So run what they recommend.
And your right, more oil per any volume of fuel means less fuel going through the jets...
Per the same amount of air that means a leaner mixture.
If your bike is stock you need less C12.
50/50 is a good place to start.
But get your jetting sorted first.
Once that is done, start experimenting with how much c12 you run.
You don't want to run any more than is required to keep your engine from detonating.
Will try some of the fuel recomendations too!
Thank you!!
Pit Row
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