Guy`s,I rode my stock 00 kdx200 for a year without any mods so I could get use to riding a dirt bike. Now I have done the mods.Installed Boyesen Reeds, Air box cover, FMF Gnarly Rev pipe, not the Gnarly torque pipe( from the suggestion of the local shop. they told me it was the same pipe but revs higher) TCII power core. 12t front socket 48pilot 155 main air screw out 1.2 turns. Now to me it feels like it has no power coming out of a tight turn in second gear until it gets up on the pipe or I have to pull in the clutch slightly to get it up on the pipe. By the time this happens I get past by everone. Is the problem the bike or bad riding habits by me?
No power until on the pipe
- Thread starter Rev
- Start date
Sounds like your dealer might have given you some "bad info". The torque pipe and the Rev pipe are distinctly different. Just look at a photo of them and you can see the difference. The REV pipe is made to increase the top end and the Torque pipe is built to increase low end and mid range power. I ride a 98 KDX 200 with torque pipe and I have ridden a similar bike with a REV pipe and the differences are HUGE. The REV pipe felt like a 125 and had to be ridden hard and "on the pipe" to make it perform. My torque pipe can be lugged all day and will rev out pretty good on top end also whan needed.
My advice to you is to see if you can ride a 95 or newer KDX with a Torque pipe and see if this fits your riding style better. Heck ... Maybe the dealer would swap with you ... "Since it is the same pipe".
My advice to you is to see if you can ride a 95 or newer KDX with a Torque pipe and see if this fits your riding style better. Heck ... Maybe the dealer would swap with you ... "Since it is the same pipe".
Canadian Dave
Super Power AssClown
- Apr 28, 1999
- 1,202
- 0
Your jetting will account for at least some of your problem. At first glance your pilot and main jet look too rich. Follow the link below and have a look at the carb tuning article. Once you have the jetting optimized it will certainly run better. I'd suggest you start with something in the 42 pilot, stock needle in the second from the top clip position and a 155 main. Remember to take a plug reading at WOT to insure you aren't running lean.
Mike's right a rev pipe will never have as much grunt off the bottom as a torque pipe but yours can be made better than it is now.
David
Mike's right a rev pipe will never have as much grunt off the bottom as a torque pipe but yours can be made better than it is now.
David
- Thread starter
- #4
Mike, You are right on. I do have to ride this like a 125. That was my first thought but wasn`t sure. It does have great power from mid to top end. Dave, I have read your tuning tips, First place I went to when I started doing my mods. Great Web site. I started out with a 42 and to me it was lean, the bike ran ok but the plug was white. Installed a 45 and the plug was getting some color to it.Thought a 48 was on the safe side.Is it better save than sorry?.But doesn`t the air screw also give you a guide if you are running the right pilot jet?. mine is 1.25-1.5 turns out. Thanks guy`s for the repley back. P.S.Listen to the just KDX web site and not the partsman behind the counter, who I think has never lifted a leg over a seat before.
For sale One slightly use Rev pipe.
For sale One slightly use Rev pipe.
Rev,
The pilot jet will not affect the color of the plug when the plugchop is done correctly. The plug color is used to adjust the main jet. The pilot jet should be adjusted for throttle response.
Dont sell your Rev pipe just yet! I have the exact same bike and when I installed my REV pipe it took a few jetting changes to get it right. It seemed to have no bottom end. I too used a 48 pilot and a 155 main because it felt lean on bottom but still had no snap. I finally changed my clip position one richer and my bottom end was back, I then leaned the pilot back to a 42 to clean up the bottom and lost no bottom end. I changed my jetting to 42pilot, 152 main, needle in middle (this made the biggest change) and the a/f screw @ 3/4 turns out. My bike is now a rocket, I cannot tell you how much of an improvment one needle clip made. Temps are 70 to 80 here in NE and I will switch to a 155 main in the winter.
The a/f screw can make a huge difference in throttle response, DONT just set it to highest idle and forget it this will NOT be the best setting. Turn that screw until your bike stands at attention when given WOT. Most a/f screws on the 200's like to be between 0.5 and 1.0 turns out.
CDave is right, keep at the jetting till you get it right and you will be rewarded. My bike is like a 250 down low and a 125 on top. :)
The pilot jet will not affect the color of the plug when the plugchop is done correctly. The plug color is used to adjust the main jet. The pilot jet should be adjusted for throttle response.
Dont sell your Rev pipe just yet! I have the exact same bike and when I installed my REV pipe it took a few jetting changes to get it right. It seemed to have no bottom end. I too used a 48 pilot and a 155 main because it felt lean on bottom but still had no snap. I finally changed my clip position one richer and my bottom end was back, I then leaned the pilot back to a 42 to clean up the bottom and lost no bottom end. I changed my jetting to 42pilot, 152 main, needle in middle (this made the biggest change) and the a/f screw @ 3/4 turns out. My bike is now a rocket, I cannot tell you how much of an improvment one needle clip made. Temps are 70 to 80 here in NE and I will switch to a 155 main in the winter.
The a/f screw can make a huge difference in throttle response, DONT just set it to highest idle and forget it this will NOT be the best setting. Turn that screw until your bike stands at attention when given WOT. Most a/f screws on the 200's like to be between 0.5 and 1.0 turns out.
CDave is right, keep at the jetting till you get it right and you will be rewarded. My bike is like a 250 down low and a 125 on top. :)
Last edited:
- Thread starter
- #6
Mac,WOW, Thanks thats great news to me and my wallet. I was adjusting the air screw to hightest idle. I was afraid to run the 42 thinking that in tight trails that it might be to lean and smoke the motor, But I`m heading out to the garage tonight to do some swapping. Thanks
Mike Hubert
Member
- Apr 22, 2001
- 164
- 0
I have a 2000 KDX220 with a Rev pipe and similar complaints. Do you think the same carb set ups recommended for the 200 would help the 220?
Canadian Dave
Super Power AssClown
- Apr 28, 1999
- 1,202
- 0
Mike,
No. The 220 uses a 33mm carb and the 200 a 35mm carb. The jetting wont be the same unless you've had your carb opened up to 35+mm or you've installed a 35mm carb off a KDX200 etc.
The fact that optimizing your jetting will improve power delivery is however the same regardless of what bike you ride. You should have piles of grunt with a Rev. pipe installed on your 220.
David
No. The 220 uses a 33mm carb and the 200 a 35mm carb. The jetting wont be the same unless you've had your carb opened up to 35+mm or you've installed a 35mm carb off a KDX200 etc.
The fact that optimizing your jetting will improve power delivery is however the same regardless of what bike you ride. You should have piles of grunt with a Rev. pipe installed on your 220.
David
Ok, I had the needle part numbers mixed up in my last response... but I changed the jets this morning to the 42 and 152 like Mac suggested, old jets were 48, and 160. The first test run was crap, the motor was sooo skippy I couldn't even get out of second, so I went to get my old jets, but they weren't there. I looked around and saw my dog was just finishing up the last bit of the manilla envelope that I had carefully put the used jets in. Stupid dog, eh, what can you do though? Since I didn't have my jets anymore, I decided to play with the needle adjustment, took it off of the second from the top, and put it in the middle adjustment, took the bike for a ride, and WOW! Its like my KDX was just freshened up! I love this bike, and I love this site! Thanks everyone!
P.S. bike is a 1995 KDX200, FMF Rev w/ FMF silencer, 13/49 gearing and a 120/100 Dunlop 752 on the rear
P.S. bike is a 1995 KDX200, FMF Rev w/ FMF silencer, 13/49 gearing and a 120/100 Dunlop 752 on the rear
Yes Brian, as I said in my original post the needle is key. I also use the stock needle. I've been running this setup since spring and my bike rips off idle to the top. Im not sure how it will act come fall so I would get a 155 main on order along with some dog biscuits. :D
Where did you put the a/f screw? try 3/4
Where did you put the a/f screw? try 3/4
Mike Hubert
Member
- Apr 22, 2001
- 164
- 0
I tried the suggestion of moving the clip 1 notch richer which on my bike was 1 step rich from the middle. I had to go to 1.5 out on the air screw and the bike is much stronger mid range and didn't bother the top end at all. I have a 2000 KDX220 with an FMF Rev bike. Thanks for all the help.
Mike Hubert
Member
- Apr 22, 2001
- 164
- 0
Mac
Thanks again for the help. I purchase the bike used from a guy who had the engine and carb done by Freddette, it is my understanding that he bores the 220 carb to the size of the 200, it that typically true? Is there a down side to running the clip 1 notch richer?
Thanks again for the help. I purchase the bike used from a guy who had the engine and carb done by Freddette, it is my understanding that he bores the 220 carb to the size of the 200, it that typically true? Is there a down side to running the clip 1 notch richer?
- Thread starter
- #17
Dave and Mac, Thanks for all of your help. looks like I`m not the only one with the problems with this set up. This weekend I dropped my pilot from a 45 to a 42, dropped the clip from the middle slot to one down. I could not find a 152 main to try, but one is on order so I kept my 155 in. Did a WOT plug chop,a has a small tan ring at the bottom. This made so much difference that I really don`t use the clutch like I had to get around the cornors in second gears. The bike really Flies now. But now I`m a confused. When I first wrote this post both of you said that it looks like I`m running rich. I lean the Pilot with a 42 will try the 152 when it gets here. But lowering the clip one notch richen the curcuit didn`t it. Why wouldn`t I raise the clip to lean it out if I was at first running rich?
Mike
I'm not sure what mods have been done to your carb but if it were mine I wouldn't assume anything.
If your bike runs better with the needle richer then your "good to go" too rich will hurt performance, possibly foul plugs and cause the power valves to gum faster but will not hurt the engine.
When jetting, jet the main at WOT for good plug color because a lean main will melt aluminum, then jet the rest of the carb (needle,clip,pilot,a/fscrew) for best performance.
REV
There are several different circuits in your carb that affect the A/F mixture at different throttle positions. Think about it..it is possible to have a carb that is too lean and too rich at the same time. Just try running a 60 pilot and a 145 main and you'll see what I mean.
Your problem was what I expierenced when switching to the REV pipe. The pilot was too rich and the needle was too lean. Once I figured that out and got my throttle response snappy again like it used to be with my stock pipe I switched to a 152 main which let the bike rev alot higher.
Please don't just assume that plugging in my jetting numbers will work for you. Jetting can vary from bike to bike due to oil/fuel ratio, temp, altitude, type of fuel, bike mods(reeds,pipe,airbox,etc..), how the air filter is oiled, air leaks, etc..you get my point.
I'm not sure what mods have been done to your carb but if it were mine I wouldn't assume anything.
If your bike runs better with the needle richer then your "good to go" too rich will hurt performance, possibly foul plugs and cause the power valves to gum faster but will not hurt the engine.
When jetting, jet the main at WOT for good plug color because a lean main will melt aluminum, then jet the rest of the carb (needle,clip,pilot,a/fscrew) for best performance.
REV
There are several different circuits in your carb that affect the A/F mixture at different throttle positions. Think about it..it is possible to have a carb that is too lean and too rich at the same time. Just try running a 60 pilot and a 145 main and you'll see what I mean.
Your problem was what I expierenced when switching to the REV pipe. The pilot was too rich and the needle was too lean. Once I figured that out and got my throttle response snappy again like it used to be with my stock pipe I switched to a 152 main which let the bike rev alot higher.
Please don't just assume that plugging in my jetting numbers will work for you. Jetting can vary from bike to bike due to oil/fuel ratio, temp, altitude, type of fuel, bike mods(reeds,pipe,airbox,etc..), how the air filter is oiled, air leaks, etc..you get my point.
Mike Hubert
Member
- Apr 22, 2001
- 164
- 0
Mac
I left the jetting alone, the only thing I changed was the clip position and 1/2 turn on the air screw. Thanks again for the education.
I left the jetting alone, the only thing I changed was the clip position and 1/2 turn on the air screw. Thanks again for the education.
Brian
Setting the a/f screw too lean will cause a lean bog and poor throttle response but will not damage anything. If you do not have a bog (bwaahhh) then you are not too lean.
Setting the a/f screw too rich will cause plug loading at slow speeds and poor throttle response but will not damage anything. If your bike sounds different(gurgley) at low speeds then you could be too rich.
As you can see playing with that screw will not hurt anything so feel free to turn that screw a quarter turn at a time then test ride, keep doing this until the bike has the best off idle throttle respose.
If your bike works best @ 1 turn then leave it there, you will probably need to go in a quarter or half when the temps drop.
I can now jet my pilot circuit by sound but before that I would slowly approach the bottom of a sandy hillclimb, put the bike in second gear and idle it close to the start of the hill, then wick open the throttle and start counting quickly. Note the amount of time it takes to come up on the pipe. Then make a quarter turn on the a/f screw and repeat the test until you find the shortest time. Worked for me anyway.
Setting the a/f screw too lean will cause a lean bog and poor throttle response but will not damage anything. If you do not have a bog (bwaahhh) then you are not too lean.
Setting the a/f screw too rich will cause plug loading at slow speeds and poor throttle response but will not damage anything. If your bike sounds different(gurgley) at low speeds then you could be too rich.
As you can see playing with that screw will not hurt anything so feel free to turn that screw a quarter turn at a time then test ride, keep doing this until the bike has the best off idle throttle respose.
If your bike works best @ 1 turn then leave it there, you will probably need to go in a quarter or half when the temps drop.
I can now jet my pilot circuit by sound but before that I would slowly approach the bottom of a sandy hillclimb, put the bike in second gear and idle it close to the start of the hill, then wick open the throttle and start counting quickly. Note the amount of time it takes to come up on the pipe. Then make a quarter turn on the a/f screw and repeat the test until you find the shortest time. Worked for me anyway.
