just finished jetting my bike and instaled new spark plugs, how fast should they turn to a tan color, just finished instaling ported intake and i was way lean with 165main and with a 185 main, plugs are still white after 10 minutes of driving., cheked plugs after full throttle and then i turned motor off, it just seems like a 185 is to big of a jet for my elevtion at 3950, bike seems ok, but is the ported lntake makeing that much of a differance. mikuni jets , dg exhaust 12 disk exhaust, moose air filter, big gun cdi, ported intake, stock carb mods.

 

Max, I would guess the 165 is a little lean. Try a 170. White plugs ona fourstroke arent bad, just as long as they are not chaulky.

 

don't plug check like a 2 stroke.

 

Yes, the ported intake does make that much difference. When I had my intake ported I also removed the airbox and went from a 165 mikuni main to a 200 mikuni main! Thats what Randall told me and it worked perfect. I was amazed but it runs great... actually I need to fatten up the pilot jet a little when its really hot... cold weather it is perfect.

What makes you think you are running fat? Are your plugs dark and/or wet? If they are still white or tan you may be right on.? How is it running? Bogs? Sputters?

 

Lid-On or Lid-Off?
DJ Needle or Stock Needle?

 

stock needle and lid on,i just think its to big of a jump but plugs are still brand new no color change after 10 minutes of driving with high rpm, also the temp here is 30 deg , dont get me wrong bike is running great, just looking for some more top end, also does anybody know the commpesion on stock motor, i was planning on doing a comp test. whats best way to plug check, thanks

 

Have you raised your needle to the highest groove - 5th groove?
Turned pilot screw out 4 turns?
What is the color of the end of plug - base before threads?
If base is dark grey with alittle black - perfect.
For the porcelean to start to show color at the top of plug takes alonger time.
If you can use a eye loupe and look down into the base of porcelean you can see the color.
As long as you do not see any light freckles of metal on the porcelean you are not too lean.
89 octane at your elevation and stock compression will give some more top.