KX Guru Racing

Definitely running cooler.... but I'll record some accutemps this weekend...

I took a long weekend and traveled south to meet up with my old man for some tard action.
When I arrived, I unloaded my bike and started it up.
It wound up to the moon.
I was grabbing the kill switch and freaking out.... but finally got it stopped.
So I checked it out and could not find anything wrong.
After I got it shut down and checked it out I tried to start it again.
Nothing... No spark...
Tried what I could but nothing worked
I guess thats what I get for using 20 year old electronics
So, I have been wanting to install my MZB ignition...
I guess this will be the week.

Old chain rollers were... well.... old
First thing I did was pop the seals and grease them good...

Look what came in today.
And it will fit 89-04 KX500 if you have the correct adapter

Excuse the messy garage...

Now for a quick recap.
I did the water pump impeller clearance mod.
I cleaned up all the water passages.
Cleaned up oil passages in the cases.
I have a re-cut head.
Chinese Rads.
Stock port timing.
Cleaned up cylinder transfers, ports, and bridges.
Balanced crank.
Wossner windowed piston.
VF2 Reed with modded boot.
41mm carb jetted a bit rich at the moment.
Running 1 qt of distilled waterper 2 oz of Royal Purple's Purple Ice (Bought it at Napa).
MZB ignition with a flywheel that is 1lb lighter then stock.
My bike has never ran so cool and with so much smooth power.
Time to start another build with some advanced port timing

According to gearing commander.com I should be able to hit 88 mph in 4th at 8500 rpms.
I can hit 90 if I flog it hard. Now to find some place I can do it in 5th. Will I hit 105?
I'll need to hit 8500 RPM's to do it.

Now that we are getting a few days that are warmer I started working on my jetting on this 41mm carb.
To be honest I have been chasing my tail on this thing.
Then, Foxx posted his 41mm carb specs at KXRiders and I finally got around to trying it.
68 Pilot
172 Main
N82N in 2nd from top
I will try to wring it out today and then check the plug and see where we are at.
My initial conclusion is that I'm closer
Thanks Foxx.

I wish I knew sooner that you were fighting with the jetting...I got my jetting where it is now, last June, and I would've gladly shared my settings back then if I had known.
Honestly, it's been one of the most fun carbs to jet, because it was one of the most challenging one's I've worked with, as this is the 1st taper-bored carb I've had.
Though I lost a substantial amount of fuel economy over the stock 39-PWK ...I am extremely happy with the performance the 41 gives now that I have it jetted.

No worries.
We were headed in the right direction.
The carb came from a knowledgeable KX guy and he had it at 52 170.
So I fought it for a while thinking that he knew what he was doing
But then I put the fact that he is knowledgeable aside and went with my gut.
We were at 60-174 when I saw your post.
I honestly thought we were even leaner.
The biggest problem is having the time to chase it down and constantly making changes to the engine.
I say it to other people all the time... Do one thing at a time!!!!
There is a guy over at supermotojunkie that tells me I'm gonna be rich.
And I didn't do the best job of explaining my jetting procedure.
He is saying 55 or 52.
Already been there.... Could not ever get it to idle right and plug was white as well as being impossible to start when it got cold out.
Tried to set him straight but I think he has his feelings hurt
Oh well, some are natural crybabies