thebreezeexc

2018 300 xcw jetting specs...

26 posts in this topic

So the manual makes it look like the 250 and 300 use the same jetting specs?? True? How can that be. I would sure think larger displacement would have different specs

Image1502329221.334133.jpg. All xcw??

Share this post


Link to post
Share on other sites

KTM doesn't know how to jet a bike, that page is to be used at fire-starter. 

5 people like this

Share this post


Link to post
Share on other sites

I've never dealt with carbs so it's strange to me as well that two different motors displacement wise run the same jetting. Makes you wonder how close the recommendations are

Share this post


Link to post
Share on other sites

I'm not having issues. Just trying to learn about these carbed bikes. I have a JD jet kit to try against stock to see how they work. Are you running the JD kit?

Share this post


Link to post
Share on other sites
1 hour ago, 2strokes_rule said:

Are you having issues?????

My 2018 runs great!!!

https://www.jdjetting.com/xcart/home.php

 

1 hour ago, thebreezeexc said:

I'm not having issues. Just trying to learn about these carbed bikes. I have a JD jet kit to try against stock to see how they work. Are you running the JD kit?

Nope! Runs great!

Share this post


Link to post
Share on other sites
What Jetting specs?!? 2018 ktm is fuel injected. 
 
Oh wait... You Americans with your stone-age carburetors.:p
I'll take the carb reliability and weight savings any day.,,
2 people like this

Share this post


Link to post
Share on other sites
6 hours ago, 95jersey said:

Wow the specs are totally different than the 17's.  27 pilot compared to 37 and 470 main vs 430.  Must be a much leaner needle in the 18's..

It's because they are using the s-4 needle jet instead of the r-8 they used in 17.  The s-4 has a larger opening, effectively making the needle smaller.  

I'm curious how guys are likeing this setup as I tried it on my 17 and it seemed too rich...

Share this post


Link to post
Share on other sites
4 hours ago, 300Braaap said:

It's because they are using the s-4 needle jet instead of the r-8 they used in 17.  The s-4 has a larger opening, effectively making the needle smaller.  

I'm curious how guys are likeing this setup as I tried it on my 17 and it seemed too rich...

I got tired of trying with stock needles on my 17 and went to JD and never looked back.

1 person likes this

Share this post


Link to post
Share on other sites

I've got a 32.5 IJ in my '18 XC at 4500 ft. I can back the air screw completely out with no real change in idle... guessing I need to go even smaller? 

The difference in jetting is way different with XC compared to the W's.

Mine came stock with a 470 MJ and 35 IJ 43-75(2).

Share this post


Link to post
Share on other sites

I have an 18 300xc and run 1 3/4 AS,27.5 pilot,stock needle setting,460 main and 6 out from seated on my idle also have vforce reeds.these are sea level 70 to 95 degree setting that are spot on for me.

1 person likes this

Share this post


Link to post
Share on other sites

my 18 300w ran like crap off the bottom which is THE common complaint with the mook.  The hot setup is "supposed" to be a cut 5.75 slide.  I did mine and will try it, but if I have the problems others are having I wont wait long to ditch the carb.  Right now I have a 36 keihin on it and it works VERY well.

Share this post


Link to post
Share on other sites
On 9/11/2017 at 8:32 AM, Sycamore said:

my 18 300w ran like crap off the bottom which is THE common complaint with the mook.  The hot setup is "supposed" to be a cut 5.75 slide.  I did mine and will try it, but if I have the problems others are having I wont wait long to ditch the carb.  Right now I have a 36 keihin on it and it works VERY well.

how did the 5.75 do? i just got my slide done and the low end bog is gone and i didnt have to mess with any jetting is that normal? im 3 turns out on my AS with a 30 pilot at 5000 ft should i got to a 27?

Share this post


Link to post
Share on other sites
11 hours ago, Hucks said:

how did the 5.75 do? i just got my slide done and the low end bog is gone and i didnt have to mess with any jetting is that normal? im 3 turns out on my AS with a 30 pilot at 5000 ft should i got to a 27?

I'm still messing with mine and not doing very well.

If your using factory needles and a full 3 turns out yeah I would go 27.5.  Think about going a tad richer on the needle, the 5.75 is quite a departure from stock.

Keep in mind I am not a jetting expert.  Never had to be with my Keihins.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with: