tank venting, sooprise!!

Larry Zoia phezanthawk at wowway.com
Tue Aug 7 16:44:56 PDT 2007

Perhaps you'll remember the thread I started a while
back about the GPZ cutting out at high speeds.  I tested
the gas flow with and without the inline filter and discovered that I got 
about ten times the flow without
the filter.  The bike has the Factory Pro Stage III kit
and K&N pod filters.

Some incidental riding and testing showed no problems.

Last weekend I went on a trip to Indian River, Michigan.
Once again, about two hours into the ride and at about
85 mph the bike starts cutting out again.

Now, after a couple of hours is when I start shifting positions, pulling my 
knees away from the tank and such.
I found that when I put my knees back against the tank, the bike smoothed 
out.  When I moved them away (again
at about 85 mph) it started to cut out again.  I tested this
repeatedly over a straight stretch at a steady speed, and
the results were unmistakable.  When I spread my legs,
the bike seem fuel starved.

I theorized that at high speeds, air flowing by the outboard pods created a 
sort of siphon effect and starved
the carbs of air/fuel.

But how is it that many on this list run the same carb configuration with no 
problems?  The answer just struck
me out in the garage.  I run the bike without the lowers so
that I can use highway pegs, and this allows air flow across the carbs.

Larry in Michigan

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