Posts: 100
Joined: 1/31/2018
Location: Rock Creek, OH USA
Just bought a brand new 250sx. get it home and i hear this knocking while at idle like detonation, pinging, what have you. i take it to the dealer and they said yes it was detonation put richer jets in it. i do that and it is still doing it but not as bad. running motorex at 60:1 and vp 110. any advice guys. thanks so much
Posts: 8299
Joined: 10/19/2010
Location: AS, USA
Edited Date/Time:
much ty. How to spot a paid forum poster/artificial forum traffic producer (see list of actions/phrases below):
Copius pattern amounts of phrases like “Anyone have”..., “Anybody know?”.... and their variations.
Thoughts?
Any help is appreciated!
Thanks in advance!
Posts: 100
Joined: 1/31/2018
Location: Rock Creek, OH USA
Posts: 940
Joined: 12/19/2009
Location: Westfield, MA USA
Do some research here and over on KTM talk, jetting issues on this machine are well documented. The shortest and easiest way to happiness will be, get cylinder head cut to close up the squish, JD jet kit, V Force reeds.
Posts: 1178
Joined: 8/20/2013
Location: League City, TX USA
I had a JD jet kit in my 13 250sx and it was night and day difference. Never fooled with jetting after that.
Posts: 1363
Joined: 3/12/2012
Location: San Antonio, TX USA
Thread that has in-depth jetting on your bike.
https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/17-TC250-Jetting-Help,1329212
Why are you running C110? It's unleaded, switch over to C12 as its leaded and will help some performance wise as well.
2018 KTM 250sx
Instagram CamaroAJ
Posts: 100
Joined: 1/31/2018
Location: Rock Creek, OH USA
Posts: 149
Joined: 2/9/2011
Location: novato, CA USA
My 17 TC250 makes the same noise. Only at idle. From my research I found that it is just a low rpm gear slap from the counterbalancer. If you take off the L side engine cover you can wiggle the counterbalancer back and forth and it makes a small clunking noise. I believe that is where the noise is coming from.
Posts: 1363
Joined: 3/12/2012
Location: San Antonio, TX USA
Posts: 100
Joined: 1/31/2018
Location: Rock Creek, OH USA
Posts: 1363
Joined: 3/12/2012
Location: San Antonio, TX USA
I was wrong about the VP110, I was thinking of C10 as that one is unleaded. The dealer I normally get fuel from is out of C12 so I'm going to get some VP110 and run it this weekend. It's really close to C12 so I'll report back if I notice any performance difference or noises.
2018 KTM 250sx
Instagram CamaroAJ
Posts: 1363
Joined: 3/12/2012
Location: San Antonio, TX USA
Posts: 61
Joined: 4/8/2015
Location: South Lake Tahoe, CA USA
my buddy's '18 250sx knocks as well. he is running JD kit. trying to figure out what it is.
my '18 300xc does not knock
Posts: 1321
Joined: 10/14/2017
Location: 86oh, CT USA
mine made the same noise. I had a 16 250sx with the jd kit. Does it get quieter when you pull the clutch in
Posts: 1363
Joined: 3/12/2012
Location: San Antonio, TX USA
