KTM's, tougher than average to jet?


Greg M

Member
Jun 25, 1999
57
0
I know the quick, and intelligent answer is no.

However, I have yet to see a consensus on what jetting works best for any of their two stroke models. I know that what works in California may not work well in Mississppi, but I tend to think that if any bike is jetted "perfectly" for 1,000 feet in elevation at 75 degrees farenheit, that it should work okay in most places.

I owned a 1994 300 and a 1997 250 and had a devil of a time getting those bikes jetted. I currently ride a Husky 360, though I am thinking about going back to a KTM 300, and the jetting I use is the same as everyone else across the country. The only slight variation is one position on the needle, or one main jet size larger or smaller.

Whenever I see a KTM post about jetting, answers vary widely as to what works. I can say that my 360 runs well from sea level to 6.000 feet. That is not to say it runs perfectly at 6,000, it doesn't, but I have yet to foul a plug since break-in.

As much as I like the bike, I am tired of the short kick start lever, high compression cylinder combination and I would like something a little bit easier to start. I also like the fact that the KTM 300 revs higher than my 360 which is all low end and mid range. It would be nice if KTM would put a six-speed gear box in the bike, but that is another topic altogether. The local dealer has three 300EXC's marked down to $4,999 and I am very tempted. Of course they will probably try to hit me with a $500 freight charge if I go in to buy the bike.

Have most of you been able to get your KTM's to a point where you can basically leave the jetting alone? Obviously a trip to 10,000 feet will not work with 1,000 foot jetting, but I think you get my meaning. I know that my last 300 was a bored and stroked 250, but it retained the cylinder and cooling system of the smaller bike and that contributed to the jetting woes. I also know that 1997 was the year that the 250, 300 and 360 shared the same cylinder and the 250 ran very cool which made that bike hard to jet. Maybe the new 300's aren't so bad.

Any thoughts are appreciated.

Greg Matty
 

Strick

LIFETIME SPONSOR
Nov 8, 1999
1,782
2
To be literal, they are just as hard or easy to jet as any other bike with a Keihin Carb. How that's for being a smart ___??

There is no mystery. Yes it takes time to get to know the bike, how it performs, and it's inherent weak areas (jetting wise), but it's not hard. If the bike (300) you are looking at is an'01, it has a #6.5 slide, which makes life easier. Once you install the correct single taper needle you are nearly there.

One thing I must say in terms of jetting. If you want your bike spot on all the time you will have to rejet with major changes in temperature, and altitude. I think this is true of most bikes.

Get the 300. You will find lots of help here on DRN, and other KTM sites. Go, go, what are you waiting for? Go.

Good LucK, and have fun!!;)
 
B

biglou

Greg-I just bought my first-ever 2 stroke, a 250MXC, and I haven't had any trouble. Strick here has helped out quite a bit as far as getting me headed in the right direction. My dealer is also very knowledgeable and supplied me with several main and pilot jets. So far all I have done is to drop the main and pilot one step each and to raise the needle clip one position (leaner). I haven't been riding for all that long but I did my research and paid attention to the ones who know and have yet to foul a plug. I'm with Strick. I say "Go, man, go!"
 

MikeS

LIFETIME SPONSOR
Jun 12, 2000
716
1
I agree with all here. Go for the new ride I too am tempted by a 01 300EXC sitting at my dealer, just waiting....I want to ride a RFS first...then I will decide...

strick...I hope you find good jetting help like the 300 for your new ride..:think sorry only kidding keep us posted once you get it

Mike S
 

Chris-NJ

Member
May 26, 2000
20
0
Me too

Greg,
I also don't want to be changing jets all the time (mostly because I don't know what I'm doing). I've got an '01 250exc and have gotten it jetted to basically a winter/summer set-up, with help from friends (I've had it for a year). 42pilot, H needle, 175 main. all i do now is raise an lower the needle for extreems. she still runs a little fat when around 90 deg., but ok with me. We ride from sea level to around 2000'???(PA/NY mountians). Good luck.
 

Strick

LIFETIME SPONSOR
Nov 8, 1999
1,782
2
Originally posted by MikeS

strick...I hope you find good jetting help like the 300 for your new ride..:think sorry only kidding keep us posted once you get it

Mike S

Mike, I am a little lost. Jetting help? I had a 1369N needle in my 380, before I even heard of Holeshot, DRN, or James Dean. I promise not to post any jetting questions about the CRF450r, only answers:D
 

MikeS

LIFETIME SPONSOR
Jun 12, 2000
716
1
Strick,
I was just trying to get your attention about the CR..hope it is what you expect.
I was ignorant with my 300 at first when jetting, overlooking the fact that my old 250 had a shaved slide and a CEJ...hearing your advice and others turned the light bulb on....:) Hope others find the same good results.
 

marcusgunby

LIFETIME SPONSOR
Jan 9, 2000
6,450
2
Greg this isnt just a KTM thing, the 2001 CR 125/250s are hard to jet right as well.If the manufacturer gets the slide/needle selection wrong to start with everyone goes off on there own mission to find the correct ones-this can lead to some interesting jetting sloutions.If the OEM stuff was close to begin with people will tend to only tinker rather than go radical. :cool:
 

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