Jetting KLX250s--Straight from Kawasaki (Technician)
#21
08-04-2018 | 06:25 PM
Senior Member
Joined: Oct 2010
Posts: 4,507
From: SW Idaho
1st Gear Member
The "muffler king" is a term of endearment we used to use for Deej. If you want to get on his good side start calling him "muffler king" he really gets a kick out of it. 
Take all the jetting advice and use it as a starting point. Your Kawi dealership guy probably is a smart cookie, (or maybe not) , but he probably didn't work on little 250klx's much. The guys on here have found what works for this specific bike, but you will still have variations, because any number of factors affect the jetting. Search jetting on here to find the best starting point, and go from there.
Dan
All hail the Muffler King
Take all the jetting advice and use it as a starting point. Your Kawi dealership guy probably is a smart cookie, (or maybe not) , but he probably didn't work on little 250klx's much. The guys on here have found what works for this specific bike, but you will still have variations, because any number of factors affect the jetting. Search jetting on here to find the best starting point, and go from there.
Dan
All hail the Muffler King
All hail the Muffler King!
hahahahaha
#22
08-04-2018 | 10:45 PM
Senior Member
Joined: Aug 2009
Posts: 4,562
From: Delaware, Ohio
1st Gear Member
My opinion - go to Pippin's site, he has plenty of tips for the KLX. He did his jetting with Kiehin parts from Kawasaki. It is pretty much the same stuff I read here on other threads and in other places on the internet, learned pre-Dyno Jet kit. My brother and I have followed it and results were good.
If you do Dyno Jet you need to get with KLXter here. Be prepared, he is Trumpish.
If you do Dyno Jet you need to get with KLXter here. Be prepared, he is Trumpish.
#26
08-05-2018 | 03:48 AM
Junior Member
Joined: Jul 2018
Posts: 10
1st Gear Member
So I have to say I was not impressed with the ultrasonic cleaner, maybe it needs to be in there more like 8 hours or overnight. I spent a lot of time on each passage and the inside of that carb. It's pretty darn clean.
I just dont forsee that kind of top end loss without a jet difference and I have not been able to get the jet spec from the all ***** out kit to compare to the stock jet.
I just dont forsee that kind of top end loss without a jet difference and I have not been able to get the jet spec from the all ***** out kit to compare to the stock jet.
#27
08-05-2018 | 12:21 PM
Senior Member
Joined: Aug 2009
Posts: 4,562
From: Delaware, Ohio
1st Gear Member
When working at the motorcycle dealership, and having cleaned some carbs for myself, we would run a carb or carb set in the cleaner for at least 24 hours. It didn't always work, sometimes taking more time. That was when the cleaning fluid was a bit more potent too.
As for your issue, there is a bit of a trick that might indicate the issue. The "choke" on the bike is an enrichener circuit, adds a bit of fuel. When you run up to the flat spot reach down and pull the choke **** out. If the engine pulls a bit stronger, not much, but likely slightly noticeable, it is running lean. Go up a jet size or two and see what happens. If it stays the same or drops a bit, it's likely a bit too rich. I used this method when I was encountering a mid range stutter at around 6000 rpm. Pulling the choke smoothed it out almost completely.
As for your issue, there is a bit of a trick that might indicate the issue. The "choke" on the bike is an enrichener circuit, adds a bit of fuel. When you run up to the flat spot reach down and pull the choke **** out. If the engine pulls a bit stronger, not much, but likely slightly noticeable, it is running lean. Go up a jet size or two and see what happens. If it stays the same or drops a bit, it's likely a bit too rich. I used this method when I was encountering a mid range stutter at around 6000 rpm. Pulling the choke smoothed it out almost completely.
#28
09-04-2018 | 01:45 PM
Junior Member
Joined: Jul 2018
Posts: 10
1st Gear Member
It revs perfect when not in gear so I'd have to try the choke trick on the road and see if that made any difference. I have adjusted the air mixture screw and it has help the bottom end a bit but top end is taped out at 6000 in gear and stuffers from around 5500 rpm. I'd think to lean but haven't been able to confirm yet. But if I clutch and give it throttle it will run up with no hesitation or studder.
#29
09-04-2018 | 03:16 PM
Senior Member
Joined: Aug 2009
Posts: 4,562
From: Delaware, Ohio
1st Gear Member
Definitely sounds lean. Do the choke trick. Unless jetting has been changed it will be lean. In Keihin parts for altitudes over around 3000 ft most run a 125 main and the N1TC needle not sure which groove, check Pippin's site, he was up around 3000 ft. For us around sea level to around 3000 run the 128 main, N1TC needle in the 2nd groove from the top, that's what myself and others run.
If using Dyno Jet, check with KLXter, he knows their stuff.
If using Dyno Jet, check with KLXter, he knows their stuff.
#30
09-05-2018 | 02:01 AM
Senior Member
Joined: Jun 2013
Posts: 3,231
From: North Texas
1st Gear Member
It would seem you still have a fault within the carb. Getting a "gunked out" CVK back in "like new" operation requires a good bit of knowledge of the componentry within..
E.G, - How did you manage to clean (and make like new) the pilot jet, the emulsion tube, pilot air jet, main air jet, the casting that is the emulsion tube "housing"...?
Could the needle jet be upside down..?
Did you test the slide operation, after reassembly, to verify proper operation.. ?
Air/vacuum leaks..? Bowl vent line routing,,?
My troubleshooting thread might help - https://www.kawasakiforums.com/forum...s-fixes-43146/
E.G, - How did you manage to clean (and make like new) the pilot jet, the emulsion tube, pilot air jet, main air jet, the casting that is the emulsion tube "housing"...?
Could the needle jet be upside down..?
Did you test the slide operation, after reassembly, to verify proper operation.. ?
Air/vacuum leaks..? Bowl vent line routing,,?
My troubleshooting thread might help - https://www.kawasakiforums.com/forum...s-fixes-43146/
Last edited by Klxster; 09-05-2018 at 02:04 AM.