CR 144 jetting ???

[imlostagain]

I just assembled my '99CR144 kit and seriously need to rejet. I broke the piston in using the standard jets as most people suggested but now I must make a change. When I asked Eric he had mentioned using 162-165 main and a 1468 needle . My concern is the standard jet in the carb was a 178. I certainly don't want to doubt Mr. Gorr , but that seems like quite a step down for the main jet. I've also read others post stating that their jetting was close to stock or made a "slight" adjustment . This is basically the first engine that I personally have attempted to jet and would appreciate any opinions on this especially from anyone that has gone through this already. If it helps at all , I have V-Force reeds,pro circuit pipe /shorty silencer, and the cylinder/head was set up for pump gas . Thanks Again .....This forum is a GREAT wealth of info !!!!

 

[cr25096er]

is it rich? go down one step at a time untiol you get it rite. lean go up one step at a time.

 

[imlostagain]

oh yeah , it is rich!!! I assume I would need a new plug for each main jet change?? Does anyone know of a cheaper plug than NGK BR9EG??(nearly $6.00 a piece locally)

 

[NO HAND]

I have a EG 00CR133 and my jetting for the Keihin carb with the v-force is 182 main, N3YK needle on 2nd clip and a 58 low speed at 2.5 turn out. The only thing is that carb is a Keihin 39mm off a 98KX500 and the needle and slide off a 99KX250. I don't know if this could actually help you. Being able to Jet a carburetor is so helpful. It's worth to spend the time to study and practice. The only down side is then all your friends come to you and ask you to jet their bike.

 

[NO HAND]

Originally posted by imlostagain
oh yeah , it is rich!!! I assume I would need a new plug for each main jet change?? Does anyone know of a cheaper plug than NGK BR9EG??(nearly $6.00 a piece locally)

You don't need a new plug for each jet change. You can feel it if it sputters like it is too rich still, go down one more until it is fixed. You just need to change the plug when it fouls or every 6 months. The BR9ES are fine to jet a bike. That's what I use when I need to rejet. Don't forget the main jet affects mostly from 3/4 open to full open. Make sure to check where in the throttle range you feel that sputtering and then tune the right circuit.

 

[cr25096er]

why waste 6 dollars for a plug? all it does it stop radio interferience but i have never seen this happen befor. a b9es will do you fine and last alot longer.

 

[imlostagain]

Ok , DAY 2 ..... Today I had quite a bit more time to work on the jetting and have it pretty close. To my surprise I still ended up using the standard 178 main but went up to a 58 pilot. I am still waiting for my needle to arrive that Eric recommended. Hopefully this won't cause me to redo everythign I've done . I must say that after some jetting and gear changes I am VERY pleased with this 144 kit.

 

[whyz]

I'm getting antsy,,can't wait for my sons motor to come home :scream:

Thats where my bike is going when i learn how to ride.>>EG's..

 

[whyz]

So what did you end up with on your jetting?
It seems to me that i would have to lean the mid to top alittle more
on the CR100.
Thanks...
I would've thought that having a bigger bore,I would have to richen it more.
Thats what i get for thinking ;)

 

[imlostagain]

To my surprise I ended up going back to the stock main 178 but did go up one size on the pilot 58(from 55) I just received my needle that I ordered nearly 3 weeks ago but havent had the chance to try it out. I'm a little shocked with the main considering everyone else dropped the main and Eric suggested going to 162-165 but the 178 gives me a nice tan color on the plugs pretty consistently. The bike is running awesome with a very slight hesitation coming out of some corners (needle should help here). My only guess in regards to the main staying so high is the V-force reed / Pro-Circuit pipe combo allowing the motor to breath better.


I can't imagine having a CR 100 as a youngster . I remember my first bike (YZ80) scaring the crap out of me at times ....And that was an '82model. Are you having problems with the jetting?