91 KDX 200 Newbie Questions

[mrmodine]

Hey guys, I have recently returned to my boyhood love of off road biking and have purchased a 91 KDX 200. The bike is in very nice condition and has a DG pipe and an aftermarket silencer, the airbox has been removed as well. I have removed the stock front sprocket and replaced with the 12 tooth. What I am noticing is that in first and second gears, I cant get much accelleration. It seems to sputter if I rev it at all and I pretty much just have to get to 3rd gear.

Any ideas on what could be causing this? I'm burning 91 gas with synthetic oil and running the 8 plug. My filter is cleaned after each ride...

Could this just be normal since I am running an older bike? (2000 miles on it) Should I be looking into a top end job? I know absolutely nothing about jetting or the reeds stuff but I'm trying to learn. Thanks for any ideas you have!

 

[BucKat]

Find out what the jetting is and get back to us.
What happens after 2rd gear? Seems odd it runs fine after 2nd only.
Check the plug color.
What's the compression?
What's your oil ratio?
Sound like it running rich down low.
Try to get your hands on a shop manual
Definitely make one change at a time and keep a log of your progress..Believe me the log will be a great asset.
Good luck
Joe

 

[mrmodine]

Thanks Joe! The bike is at a buddy's house cuz I don't have a trailer yet and we're going riding Friday through Sunday. Will check compression and jetting this weekend and get back to you. Thanks Again! Christopher

 

[BucKat]

While riding..try adjusting the airscrew.
Make small adjustments of 1/8 turn or less at a time...1st find out where is now (log that). should be around 1 1/2 turns out.

have fun.
Joe

 

[David Trustrum]

Straight off check the just-kdx website for jetting starting points. While you are at it clean/replace that old airfilter, check the powervalves are working & try a new plug & plugcap.

When I test rode my ’91 I could not believe the guy ever rode it like that –sounded like it was underwater, but I knew it could be fixed. Jetting is hoougely off std & most people don’t bother to buy a couple of jets to fix it. Blow the passages of the carb out to see they are clean as well (but never poke anything through them).

PS use the search key above to search for past threads on pvs etc.