My bike is running poorly

[Racerjoey1]

I have a 1996 KDX200 and it has not run good since I have had it. I didnt know that it wasn't running good because I was new to bikes when I bought it. It has a k-35 torque pipe, boyesen rad valve, and a Turbine core silencer. It seems like its not revving up as much as it should and it barely pulls the wheel off the ground in 1st gear. I have to yank up pretty hard to get the front wheel up in 1st gear. I am pretty sure that a stock KDX should be stronger than that. Also, here recently it is harder to start. It takes about 4 or 5 kicks with the choke on when it is cold. Then when it does start it idles very high for a few seconds. When the motor is warm it starts on the first kick. The bike is fun in the woods but I just wish it was faster. I think I may need a rebuild and a rejet.

Any ideas?

Joey

 

[davidg]

Sounds like you've already answered your own question. How long has the top end been in there, do you know what jets your currently running? You might want to go ahead and check the reeds while your at it.

 

[john_bilbrey]

Ditto. See if you can get a compression test done. Either way, it is probably due for a top end and proper jetting as mentioned above. How about your air filter? Is it clean and in good shape? With the mods you have listed, you should have a fine running machine. It's probably nothing that a little required maintenance won't fix.

 

[Racerjoey1]

How can I tell what jets I am running now? Do they have a number on them or do you just have to know? I haven't done any mods to the bike since I have had it so I dont know. The guy I bought it from said it had a fairly fresh top end but I guess only he really knows.

Joey

 

[drdavidjr]

Check your carb first. I would spray carb cleaner through the jets first before changing anything else. If you notice an improvement, have your carb cleaned by a experienced mech.
I had a similar problem with my bike.

Good Luck

 

[CaptainObvious]

Each jet has a number stamped on it. So does the needle.

Has the bike always been this weak, or is this a new condition? A sure sign of needing a top end is an engine that gets progressively worse; harder to start and down on power. With the exception of atmospheric variations, jetting will remain static. It can be off some days and better on others, but it will not change to a worsening condition over time.

Before you start messing with the jetting or chasing other squirrels up a tree, have a compression check performed. After all, the bike is 7 years old so it must have a couple hundred hours on it, right?

 

[Racerjoey1]

It has always been down on power, but I just noticed the harder cold starts recently. Maybe that is because it has just gotten to where it gets really cold outside now. I actually went out and rode yesterday and the bike felt a little stronger. I think that was because it was colder out, so the air was more dense. The bike is running way rich so I am gonna rejet it very soon. I am afraid to get into the topend, I dont want to see all the carbon thats bound to be in there.

Joey

 

[CaptainObvious]

Originally posted by Racerjoey1
I am afraid to get into the topend, I dont want to see all the carbon thats bound to be in there. Joey

All the more reason to tear it down.

 

[Racerjoey1]

If I keep the bike I am gonna have to do all this stuff to it. I think it would be worth it for me. But, last night I had a guy offer me $2000 for a 96 KDX that I paid $1500 for. I told him its sold. He said he wants to do something around the first of the year so if he does offer me that money still Id be dumb to not take it. If I sell it I will probably get an XR400 or another KDX. I would like to try a 4 stroke out though and if I dont like it I can always sell it down the road.

Peace,
Joey