Big Mike wrote on 02/10/17 at 06:02:46:This isn't my first rodeo rebuilding parts on a bike, but now that I know that the Raptor mod is to fix an underlying issue of a failure that doesn't seem to fall into a pattern, I'll order a Raptor one when I order some parts for my R* this weekend.
My "strong" suggestion was not made to imply any lack of ability....it was more intended in an effort to keep your son out of trouble. When the petcock begins to get fussy.....it can cause all kinds of weird symptoms....one of which is the bike can suddenly stop running when you need it most. One of our forum members was passing a truck on the interstate and had the throttle open in an attempt to get the pass done, and suddenly the bike stopped running. It turned out that when the throttle was opened up and the vacuum in the carb dropped....there was not enough of a vacuum to operate the petcock. For other owners the bike can get too rich as a result of the petcock leaking fuel down the vac line......and others have had erratic behavior that has them chasing down electric gremlins that don't exist. Changing cams, exhaust or air filters may also alter the vacuum and the proper operation of the stock vacuum petcock.
I didn't want your son getting stuck in a bad situation......when it could be avoided. Show him how to use the golf tee and vacuum cap to bypass the vacuum line and use the PRI.....and he will be able to make it back home!