I have a polaris 400 race mod 300 ft drag race it runs good but it runs better after dark it has 13/34 gearing, race pipe,race port,12:1 compression, vforce II reeds with spacer,tmx 42mm current jetting is 410 main and a 30 pilot does this jetting sound too rich?

 

Considering the stock Mikuni ran a 240 main and 30 pilot,does sound too rich even on the Tmx carb. Look over what jetsrus has for a jet kit along with separate jets.https://www.jetsrus.com/a_jet_kit_at..._1997_2002.htm main thing is to plug chop it. Get the machine at a high speed and hit the kill switch. Stop as soon as you can,let it cool down and check the color of the plug. Should be a tan to medium brown color if jetted correctly.

 

Would it be safe to try a 20 pilot and about a 390 main

 

Pilot should be ok. Try the plug chop first to see where you stand on the main jet. If it's too dark,then you need to go down on the main.The more mods you add the more it sometimes takes to get jetting right.

 

The plug is dark brown but it's a little wet

 

If that's the color after a high speed run and quick kill,then drop the main to the 390 and take it for a spin and see how it does. A little on the rich side won't hurt,but you don't want the plug to look whitish in color.