Switched from 32:1 to 40:1, now I'm fouling plugs
 

I used to run 927 at 32:1 with no problems, jetting was right on the money. I wanted to try a synthetic and since I had always liked Benol, I called up Klotz and they recommended their R50 at 40:1. Now I'm fouling plugs after about an hour of riding. My buddy's Shee is doing the same thing. The guy at Klotz said the Shee should run it at 32:1 and I should lean out my needle and main.

Now I know that reducing the amount of oil in your fuel will cause you to run rich (in terms of air and fuel), but should it richen my mixture enough that I'm fouling plugs? Or is this oil crap?

Switched from 32:1 to 40:1, now I'm fouling plugs
 

Far from crap{ in my opinion} You will have to jet down if you change ratio's, no big deal to do.
why did you change your ratio? Just curious. Drop your raise your clip one notch and maybe
one or 2 sizes on your main. I've use Klotz but I run 32:1. Good Luck !

Switched from 32:1 to 40:1, now I'm fouling plugs
 

The dude from klotz told me to run it at 40:1. I had always heard that you run synthetics at higher (thinner) ratios than castors, so it made sense to me but what do I know.