Jump to content
Sign in to follow this  

2004 Ktm 450 exc won't start after removing carb

Recommended Posts

Alright, so my dad recently bought a 2004 Ktm 450 exc with 5.5 hours on it that had been sitting since it was first ridden and put away dirty. I assume jetting is stock. He took the bike out immediately after buying it, and it was rideable, but would not run without the choke on. Today he swapped out what seemed to be a clogged 42 pilot jet for a new 45 after changing the oil and oil filters. He was able to warm it up with the choke on to do this, and it would briefly run with the choke off if he revved it. The new pilot jet was marked 45S while the old pilot lacked the 'S'; is the 45S the wrong pilot jet? After he reinstalled the carb with the new 45 pilot, the bike wouldn't start, and would backfire every few kicks. He assumed it was an air leak and sealed the carb boot with silicone. Since then there hasn't been any change, although he's reassembled the carb, checked to make sure the passage above the pilot jet is clear, set the float level according to the manual, and filled the tank with fresh gas. At one point, the carb seemed to drain gas through the vent hoses with the float bowl drain screw tightened, but this problem disappeared. I don't know if it matters, but the battery is dead so he disconnected it; could this be what's preventing the bike from firing? I've read numerous threads and it seems like the problem is oftentimes an improperly installed slide, which has to be "square side down". Could someone elaborate on this with pictures? What else could prevent the bike from starting? 

 

I'd really appreciate it if someone could help diagnose this issue. It's especially frustrating given that this bike has so little time on it.

Edited by Nick Merrell

Share this post


Link to post
Share on other sites

REMOVE ALL THE SILICONE!

 

That it going to cause problems later. you don't need it.

 

Have to have a battery

 

Have to use a 45 (not s) pilot, brand new.

 

GET A SERVICE MANUAL

Thanks for the quick response. We'll remove the silicone and there's a service manual, battery, and 45 pilot on order. For now we're going to try and start it with a cleaned 42 that came with the bike. I don't think that it needs a battery to run because he was able to ride the bike without one; it just wouldn't run with the choke off.

Share this post


Link to post
Share on other sites

Alright, we finally got the bike running a couple days ago. I just wanted to post this in case someone is having the same kind of problems. The bike ran with the 45 pilot and new carb seal but was way too lean. It boiled over after a few minutes of idling at ~200ft above sea level. Supposedly from what my dad has read, a 48 pilot should do the trick as would a richer needle. Both of those parts are on order and I'll update once it's finally solved. Thanks again for the help.

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  

×