Jump to content
Sign in to follow this  

Help! 98 kx 250 issues

Recommended Posts

Hello all,

New to the forum and just getting back into the sport.

I purchased a 98 kx250 about 2 weeks ago that has a few problems.

Initially the problem was a rattle in the crank case. The rattle was present with the clutch engaged OR disengaged.

I changed the trans oil and the noise went away.

After running the bike down the neighborhood it did not want to stay running. Visually inspected the engine and found the head gasket blown with 2smoke fuel running down the cylinder. Pulled the plug and and found water droplets on piston top.

Also the gear oil went wayyyy down on sight glass after riding for a few minutes. There is no sign of an oil leak from the bike. Maybe a bad seal that is using the gear oil?

Any help will be much appreciated

ImageUploadedByThumper Talk1407696251.238653.jpgImageUploadedByThumper Talk1407696271.388315.jpgImageUploadedByThumper Talk1407696290.073289.jpg

Share this post


Link to post
Share on other sites

Looks like it has a blown head gasket.  If its consuming trans oil and definitely not just leaking its a bad crank seal, which is a major repair.  Usually that means the crank and main bearings are severely worn as well.

Share this post


Link to post
Share on other sites

You will have to have the cases split to replace the KX seals..If you have nay concern that the crank is bad then have your oem crank rebuilt with a rod kit. It will cosat the same as buying one of the pos imported cranks.. I just saw a nos crank for your bike on ebay for $199 shipped.

Share this post


Link to post
Share on other sites

I will update the thread this coming up weekend. Moving into our new house and will start the tear down

Share this post


Link to post
Share on other sites

It's normal for the 250's to rattle a little with the clutch engaged in neutral, but it goes away when you pull the lever in.  

Share this post


Link to post
Share on other sites

I've been told that. It would rattle with the clutch lever pulled or not pulled.

Share this post


Link to post
Share on other sites

Could be a badly notched clutch basket..the more notched the worse they rattle..As for the trans oil be low..Pull the pipe and if it has oil in it then it needs major attention.

I bought my current 99 bike and ran it for ten minutes and it smoked like a freight train...when I pulled the pipe it had nearly half of quart in the pipe...holy smokes batman..

I thought it had to be a bad crank seal....but when i split the cases I found it had hole where the case halves meet and the previous owner tried fixing it with silicon.... :facepalm:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...