OK - I'm trying to make sense of the SN6000 issue and one of the symptoms seems to be the result of backfiring. Please feel free to correct me - but isnt backfiring an indication of a lean condition in a 4-stroke?? If so, wont simply re-jetting to the proper mixture prevent backfiring and thus, the "carb blow-off issue". I'm guessing lots of guys are adding pipes and opening air boxes without re-jetting which would likely result in a lean condition!?

Here's a test - for everyone that has "blown the carbs off" (be nice) check the spark plug for a chocolate brown color. If it's white = lean, Black = rich.

I may be way off base so please let me know what you think.

See ya -

 

Try this set your idle up a little more and take the spacers out of your clamps on the carbs and tighten them up or get some bigger stainless steel hose clamps and put on there.Some people say that is 22.5 pilots are to small and that you should run 25.This may sound weird but its seems that the black and white raptors run leaner than the blue ones.

 

yes, the B/W color of the bike absorbs the sunlight differently than the blue color, thus causing the bike to gain quantum energy and begin to vibrate at a harmonic frequency that is exactly the frequency needed to pop the carbs off the boots. no amount of tightening or re-jetting will correct the problem. it is a MAJOR design flaw of yamaha. they should have known better.[img]i/expressions/face-icon-small-shocked.gif[/img]

oh, btw... mine is an older S/N, blue in color and i rejetted to 27.5 after only about 1 hr of motor time and i have NEVER blown the carbs. but... i'm sure that CAREFUL tuning, adjustment of the idle circuit and larger pilot jets have NOTHING to do w/ it. just MHO, tho'. later.

 

On a spring day with temperatures in the thirties I saw a Yamaha Warrior also pop a caburetor off it's mounts. Is this unique to Yamaha? [img]i/expressions/face-icon-small-shocked.gif[/img]

 

I said it just seemed weird,but you still smoked me.I know left myself open.

 

27.5 pilots seem to fix the problem, thats what I have installed, not a single backfire yet..

Brad