Jump to content

No compression

Recommended Posts

Hello everyone I bought a 2006  ktm 250xc and the previous owner fully rebuilt the whole engine and it had plenty of compression, I broke the bike in and then took it to sand mountain, after 2 days of ridding I had lost all my compression and I can move the kick starter with 1 finger but the bike starts up right away between 1-3 kicks and has a lot of power, overall the bike runs strong but it just feels like there’s no compression, anyone have any idea of what it might be ? Thank you.

Share this post


Link to post
Share on other sites
12 hours ago, paul karpenko said:

Hello everyone I bought a 2006  ktm 250xc and the previous owner fully rebuilt the whole engine and it had plenty of compression, I broke the bike in and then took it to sand mountain, after 2 days of ridding I had lost all my compression and I can move the kick starter with 1 finger but the bike starts up right away between 1-3 kicks and has a lot of power, overall the bike runs strong but it just feels like there’s no compression, anyone have any idea of what it might be ? Thank you.

I can move the kick starter on my 300 easily if I let it go real slow, but try to push it down fast as if starting it and you'll probably break your finger. 

I dont know about the 250s but the 300s have a hole in the cyl that let's some compression leak out at kicking speeds maybe this is what your feeling.

Edited by Ievko82

Share this post


Link to post
Share on other sites

I used the finger as an example, what I’m basically saying is that it feels as if there’s no compression what so ever, zero resistance 

Share this post


Link to post
Share on other sites
3 hours ago, paul karpenko said:

I used the finger as an example, what I’m basically saying is that it feels as if there’s no compression what so ever, zero resistance 

Even if you push down on it fast?

Share this post


Link to post
Share on other sites

Either you sucked dirt and damaged motor parts, or the motor was wore out, and previous owner did a Half A$$ rebuild. Regardless , will have to tore it down  again for inspection.

Share this post


Link to post
Share on other sites
7 minutes ago, Spud786 said:

have to tore it down  again for inspection.

Agree, but I'd measure compression before tear down just to see how low it is. If it's very low you had realized that while riding....

  • Like 1

Share this post


Link to post
Share on other sites
On 9/29/2019 at 12:51 AM, paul karpenko said:

Hello everyone I bought a 2006  ktm 250xc and the previous owner fully rebuilt the whole engine and it had plenty of compression, I broke the bike in and then took it to sand mountain, after 2 days of ridding I had lost all my compression and I can move the kick starter with 1 finger but the bike starts up right away between 1-3 kicks and has a lot of power, overall the bike runs strong but it just feels like there’s no compression, anyone have any idea of what it might be ? Thank you.

I've seen guys suck sand into the airbox destroying the motor.

Start with a compression tester. Like mention above.

Might only need a fresh ring job.

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:


×
×
  • Create New...