Jump to content
Sign in to follow this  

Jetting

Recommended Posts

I know every one is probably tired of jetting questions, but I have one. I live at around the 4800 elevation level. My XR400 is set up with a 440 big bore kit, snokel removed, plug resistor removed, exhaust completely gutted and the air filter sceens removed, (all except one). Could some one tell me what jets to start with, so I can attempt to get my jetting right. I think I have 148 and 52 combination currently in it.

Thanks, Josh

Share this post


Link to post
Share on other sites

That 142 main is too lean for sure. I would suggest a 55 pilot. That 52 may be close, it just depends. No matter what I did, I could not get my pilot sysem to dial in for the increased displacment of the 440. My 155 main wasn't bad. I'd start with a 155 for the main. That will be close. I live at 3600'.

I'm afraid that gutted exhaust and how open you have things, from intake to exhaust, along with the increased intake/draw of the bigger displacement, is going to overwhelm the stock carb and make it very difficult to jet with any satisfaction. People have had varying degrees of success. You'll just have to see how yours does.

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...