KDX rejetting - Where to go?

[benjy]

I have a 97 KDX 220 that has fouled 2 plugs within 4 or 5 rides that I've owned it. As much as I would love to read up on this and do it myself, I currently have more money than time and a trip planned for November with nothing but work and school between now and then :-\ .

Any recommendations on where to take it, and about how much it I should expect to pay? I would even trust someone on here if you know your stuff and will stand behind your work.

 

[Greg]

I heard you say you don't have the time, but I think you should do a bit of research and DIY just to learn more about how the bike works. Talk to the South Valley about the proper jetting for the elevation you ride the most, they could probably recommend the right jetting and probably have the parts.

I had to rejet my bike this Summer and also did some performance mods while I was in there. It didn't take that long and the learning experience was invaluable. The bike also ran much better!

 

[Rot Box]

I spent half my life on a 97 KDX200 :greg: Awesome bikes to say the least!

I agree with Greg. Jetting is a very easy thing to do once you understand the concept and your Keihin carb is as simple as they come.

Starting, idling and up to 1/4 throttle relies on your Pilot jet. 1/4 to 3/4 throttle relies on your needle and 3/4 trottle to wide open throttle (WOT) is your main jet. Most people get by with changing the main jet to eliminate fouling and sometimes that's the problem but all should be checked. The larger the number on the jets or the higher the needle is raised the more fuel is pushed into the engine and depending on the throttle position determines which jet is doing what.

Also what two stroke oil do you run? Having owned several Kawasaki's I will say the KIPS power valves are very temperamental when it comes to the type of oil being ran. These years KX/KDX are known for fauling out plugs if you use poor 2 cycle oil. Also remember that oil mix ratio has NOTHING to do with jetting. Most confuse this and assume more oil will make you foul out easier. That is not the case unless you put an excessive amount of oil in your fuel. I always ran mine at 36:1 and had great results.

For now I would call up the Kawasaki dealer and ask them what jets/needle should be in YOUR bike (tell them you want to know what would come in it if it was sold here at this elevation--they do know.... or should), install them and go from there. This will help you get close (but probably won't be perfect) and tune from there.

I would be more than happy to jet it for you, but I live up here in Cache Valley. I have seen too many people pay too much money for someone to jet there bike and have it be way off of where it should be.

I can elaborate a little later but for not I've got to go wheelin! :greg:

 

[Jared]

Also remember that oil mix ratio has NOTHING to do with jetting.

This is only partly true. A richer oil mixture will actually thicken your fuel consistency. This will in effect lean your jetting, particularly at wide-open-throttle where fuel flow is greatest. It is not a very big factor, but can equal one or two main jet sizes. We went from a 50:1 Klotz synthetic to a 32:1 honda lube and had to go up 2 sizes to compensate.

Float valves getting stuck or bent can also effect jetting. If your fuel level is too low in the bowl, the fuel has to be sucked farther up each jet. This also will effectively lean your fuel mixture. Too high of a fuel level will richen it.

These factors will probably not effect your KDX, but it looked like a good thread to toss out this info. Greg and whatsizname are correct, it's not very complicated and will take only a few hours. You will also gain the benefit of knowledge, and be able to re-jet your bike quickly if you plan a trip at much different elevation than where you normally ride. Remember, "The doer alone learneth."

Jared

 

[benjy]

I heard you say you don't have the time, but I think you should do a bit of research and DIY just to learn more about how the bike works. Talk to the South Valley about the proper jetting for the elevation you ride the most, they could probably recommend the right jetting and probably have the parts.

I had to rejet my bike this Summer and also did some performance mods while I was in there. It didn't take that long and the learning experience was invaluable. The bike also ran much better!

Was that your first attempt at rejetting? I'll give South Valley a call and see if I can get the right parts for this altitude.

I spent half my life on a 97 KDX200 :greg: Awesome bikes to say the least!

No kidding! I did a lot of reading before picking up this bike. I wanted a simple, reliable, woods bike. I have been extremely happy with the rides that I have had it out on.

Also what two stroke oil do you run? Having owned several Kawasaki's I will say the KIPS power valves are very temperamental when it comes to the type of oil being ran. These years KX/KDX are known for fauling out plugs if you use poor 2 cycle oil. Also remember that oil mix ratio has NOTHING to do with jetting. Most confuse this and assume more oil will make you foul out easier. That is not the case unless you put an excessive amount of oil in your fuel. I always ran mine at 36:1 and had great results.

I have been running Klotz 80/20 at 40:1. My FIL is convinced that is why they've been fouling. He's says I just need to switch to full synthetic at 50:1. Everything that I read before I bought the bike indicated this was not correct. I get a lot of spooge as well. I think that's what it's called After a day of running, the exhaust is practically dripping with oil, and it sprays the underside of the bike.

I have seen too many people pay too much money for someone to jet there bike and have it be way off of where it should be.

That's really what I'm afraid of :-\ There is an aftermarket pipe on it and some holes cut in the airbox, will this affect which jets and needle I should use?

Remember, "The doer alone learneth."

:guilty: I keep meaning to change that... Seems like I haven't had time to do hands on anything lately :-\

Thanks for all of your inspiration, guys. Looks like I've been able to free up quite a bit of time next Saturday, so I'll give it a shot. Found plenty of reading here.

 

[Greg]

Was that your first attempt at rejetting? I'll give South Valley a call and see if I can get the right parts for this altitude.

Yes, it was. I've rebuilt many automotive carbs so I was familiar with the basics of how things work in a carb, but this was my first motorcycle carb. I did the same thing you did, found a good link about going thru the carb, read it several times, then set aside an afternoon going thru the carb. I modified a few things and really opened up the bike.

 

[Corban_White]

That is one of the best writeups on carb tuning I have ever seen. Swapping out jets is really easy and almost takes no time, getting the jets right can take a bit more time since it is just trial and error. The bike has likely already been rejetted since the mods should have made it run leaner. You should be able to get the parts down here in UT co even w/o a kawi dealer. IIRC the jets for a Keihin round slide are the same for most bikes they are installed in. Most jetting changes can be made w/o even removing the carb from the bike and I've even done them on the trail to compensate for altitude. (just don't drop the pieces!) The first thing I would do is find out what jets are in the bike currently since you have increased airflow. It may be that you need to put the stock sea level jets in. Regardless, rather than starting from where the book says, I would start from where you are at. Let me know if you need a hand, I am available mon, tues, thurs after 4:30.

 

[benjy]

Let me know if you need a hand, I am available mon, tues, thurs after 4:30.

I might take you up on that... I'll call you if I can free up some time this week.

 

[Rot Box]

I have been running Klotz 80/20 at 40:1. My FIL is convinced that is why they've been fouling. He's says I just need to switch to full synthetic at 50:1. Everything that I read before I bought the bike indicated this was not correct. I get a lot of spooge as well. I think that's what it's called After a day of running, the exhaust is practically dripping with oil, and it sprays the underside of the bike.



That's really what I'm afraid of :-\ There is an aftermarket pipe on it and some holes cut in the airbox, will this affect which jets and needle I should use?

I run the Klotz 80/20 (40:1) and love it. Some say that the 20% castor can contribute to the excess goo but I don't know if its been proven. With proper jetting you should not foul often or ever on the 80/20 or R50. The goo is normal to an extent, but I suspect your power valve needs to be cleaned out. The KIPS holds a lot of crap in there! I didn't think of this earlier, but do you have the stock silencer/spark arrestor? My stocker was plugged up (and there is no way to clean them) and it caused me to struggle with jetting and I often fouled out. Getting rid of that was the best move I made on the KDX seriously.

I removed the air box lid completely, had minor porting and a full exhaust system on mine and I had to drop the jetting a lot. I would get with Corban you will really like it once it is properly tuned :greg:

 

[pELYgroso]

would y'all say that a kdx 200 or 220 would be a step up from my wife's xr 200? She loves her xr but could use a little more power without a much bigger bike (250's are a little big) sorry for the hijack.

 

[Corban_White]

I might take you up on that... I'll call you if I can free up some time this week.

I just remembered no scouts this week so I should be free wed too.

would y'all say that a kdx 200 or 220 would be a step up from my wife's xr 200? She loves her xr but could use a little more power without a much bigger bike (250's are a little big) sorry for the hijack.

Any time you want to try out my wife's crf 150 feel free. It has more power and better suspension than the xr200 on about the same size frame and lighter to boot.

 

[Rot Box]

would y'all say that a kdx 200 or 220 would be a step up from my wife's xr 200? She loves her xr but could use a little more power without a much bigger bike (250's are a little big) sorry for the hijack.

The KDX is a step up for sure, but keep in mind that the water cooled KDX's are basically the same size as a modern 125-450. Assuming that your XR200 was made in the 90's the KDX would be quite a bit taller. They have one of the most user friendly/reliable 2 stroke engines ever made with VERY good handling. I just wish Kawasaki would have offered them in a 300 or 350 instead of the 220 :-\

 

[benjy]

I was finally able to spend a little time working on this tonight... Turns out my float level was way out of whack. Also cleaned out the pilot jet and main jet while I was in there. I'll put it all back together and see what affect the float level was having on it. Apparently it can cause signs of running rich/lean.

I was somewhat uncertain tearing into this, but it was all for nothing. It's all pretty simple, and I'm excited to start fine tuning it!

 

[Greg]

See, it wasn't that bad! You saved a few bucks and learned a lot about your bike and the carb! Congrats, it looks real good and the reward when you crack the throttle will be all yours!

 

[Corban_White]

Very nice!

 

[Rot Box]

Looks good hope it all works out for ya

Is it just me or can spring not get here fast enough?!

 

[Greg]

... Is it just me or can spring not get here fast enough?!

It's not you! I almost got out the TTR last week when the temps got up into the high 30's and most of the ice was melted off the roads. I can't wait for Spring!

 

[Corban_White]

With my fathers recent acquisition of 5 snowmobiles, I LOVE winter!! I get to ride all year round!

 

[Caleb]

Is it just me or can spring not get here fast enough?!

Man, that's too true. I keep getting ready to go out and ride and then get to the garage and decide it's too cold I only got a couple weeks of riding in before it got too cold out last summer/fall so I'm really itching to get out there.

This thread is good info, I was going to try and find someone to take mine to. I think it needs to be rejetted. Maybe I'll try it myself I've torn apart and cleaned four-stroke four-wheeler carbs many times, but have never rejetted.

 

[Jared]

Is it just me or can spring not get here fast enough?!

Screw that! I still have a ton of crap to get done on mine. I need at least two more months to procrastinate!

Jared