Posts
136
Joined
1/11/2011
Location
pittsburgh, PA, USA
Edited Date/Time
5/10/2020 6:42pm
Hey! I just picked up a new toy. 2018 ktm 250sx with 3hrs , previous owner bought and said it was too much for him.
He ended up putting on the following:
-v force 4 reeds
-fmf fatty
-pro circuit 304 silencer (not sure why he mixed and matched)
I took it out yesterday and messed with the jetting, was a lot better but still not great. I went from stock to the following pilot-37.5, airscrew 2 out, main 460, needle on third clip). It felt like it was super rich on the bottom and mid, and didn’t have much over rev prior to my changes. Still feels like the midrange is really rough.
I also ordered a JD jetting kit. I’m surprised how expensive they are. Has anyone found other needles that u can order that work great cheaper?
Also I’m planning on buying a steahly FWW, should I go 9oz or 11oz for MX? What sucks is RM only has the 11 oz, to get the 9oz have to go to manufacture and pay more and shipping ??♂️.
Here are some picks of the bike, and my arm after I made it medium well while jetting on the pipe
.
He ended up putting on the following:
-v force 4 reeds
-fmf fatty
-pro circuit 304 silencer (not sure why he mixed and matched)
I took it out yesterday and messed with the jetting, was a lot better but still not great. I went from stock to the following pilot-37.5, airscrew 2 out, main 460, needle on third clip). It felt like it was super rich on the bottom and mid, and didn’t have much over rev prior to my changes. Still feels like the midrange is really rough.
I also ordered a JD jetting kit. I’m surprised how expensive they are. Has anyone found other needles that u can order that work great cheaper?
Also I’m planning on buying a steahly FWW, should I go 9oz or 11oz for MX? What sucks is RM only has the 11 oz, to get the 9oz have to go to manufacture and pay more and shipping ??♂️.
Here are some picks of the bike, and my arm after I made it medium well while jetting on the pipe
.
5.75 slide
https://www.motosport.com/oem-parts/part-number/16025-0003?mmysource=ka…
Needle
https://www.motosport.com/oem-parts/part-number/284-14116-H5-00?mmysour…
The parts from KTM you’ll need are a S4 needle jet from a ‘18 250/300 XC. Stock you have a S1.
This is how you should set it up
MJ 470
PJ 32.5
Needle 42-75
Clip 4th position or 3rd depending on temp.
Needle jet s-4
AS 1.5
C12 or pump mixed 60:1
Power valve 1 3/4 turns in from all the way out.
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Free shipping: VITALMX
Luxon 4-Post Bar Mounts
$189.95 - $239.95
The bike was jetted like shit from the factory. If you call JD they will send you a kit that tailored to your bike. I didn't feel like messing with a bunch of jets to get the bike right. The set up JD gave me was spot on and the bike ran perfect.
Thanks
Rob
You have the late style.
On the slide, no. You can send to http://www.rb-designs.com/ and have them cut your stock one to a 5.75 for like $30.
That made the biggest difference for me, and switching to a Keihin...
Pit Row
Just look up "Jarvis Mods"... great bike and easily sorted with just some time and a few bucks.
Make sure and check the float height as well, if it's off even 1 or 2mm it can really fuckulate the way it runs down low. Chances are it will piss out a bunch of fuel as well if the float is set high like mine was.
I filed a notch in the stock slide on my 19 TX300 and it runs well. But buying a leaner slide would probably be the better option.
also i looked at the clutch weight its a interesting idea, can anyone give me the negatives of the clutch weight. It seems easier to instal, from what i read the clutch spins 1/3 as fast as a Flywheel so the weight needs to be more to achieve the same effect?
I am afraid that the 5.75 of the kawasaki is too lean in the Netherlands in the sand.
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