rejetted with obeln.

3 replies to this topic
  • Descendents

Posted May 05, 2003 - 03:57 PM


I have been reading posts from this site all winter and decided to try to rejet my 2002 426. This past weekend I put a obeln needle in it on clip 3 and left everything else stock. I also put a p-38 cover on it that a guy from work gave me. I noticed a big difference on how the bike runs, it seems to rev quicker and was a rocket as I ripped through the gears. I didn't feel any missing anywhere and it did not pop.

My question is when I pulled my plug after ridding it twice, it was black. Before I did the rejetting, I would pull the plug and it would be really wet and black, now it really wasn't wet, but just black. I was wondering what part of the carb should I concentate on to lean it up some, pilot, neddle or main. I have never seen my plug look anything else but black since I have owned the bike. I would think that if I could get the plug tan it would be running at its peak. Any help would be greatly appreciated. I ride in Michigan, around 1000ft, this past weekend was around 60 degrees.

  • Indy_WR450

Posted May 05, 2003 - 04:03 PM


Yamaha fourstrokes will show a black wet plug when idling before chopping. I would call it normal and not worry about trying to clean up the pilot jetting. If the bike is running well off idle I would leave it alone.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • MN_Kevin

Posted May 05, 2003 - 04:41 PM


You have to break down your jetting to top end, mid range and bottom end, and test each accordingly.

  • Chas_M

Posted May 05, 2003 - 07:52 PM


The tip of the obeln needle is much smaller (richer) than most other needles, therefore a smaller main jet may be required.


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.