WOT sputter, where to start?

[theredark]

Hi all,

I have a 2000 I/S with original fuel petcock,  new OEM cover set installed.  New vacuum line installed to petcock . DanMarc fuel shutoff inline.  I've checked filter screen and it appears clean and not collapsed.  Bike runs great at idle, nice crisp response rolling on the power but when I get to wide open in upper gears there is a slight sputter.  I've run about a half bottle of techron through the last tank before storage and used Startron all last year.  I put the bike away for a few months and will be pulling it out in another month or so.  The bike has approx. 29K miles on it.  Plugs were changed at 24k.   Any thoughts?

thanks,  Brad

[Bone]

The bike ran bad when you put it in winter storage ?
Did the bike have the problems before the in line shutoff and cover-set installation ?

Just trying to eliminate changes that didn't hurt performance.

[Patrick]

It sounds like insufficient fuel flow.. I'd look at the petcock and electric shut-off installation..

[Daniel Meyer]

It sounds like insufficient fuel flow.. I'd look at the petcock and electric shut-off installation..

That's my vote. WOT is the reason that fuel line is so big! That engine will SUCK the fuel.

Also check battery condition too though...at high rpm the ignition uses a LOT of power.

[larswlvs]

To me it sounds like you may have a pinched fuel line...It's easy to do when you  add to the line and make it longer. Don't ask me how I know that.

[Challenger]

I know of two Valks, one I/S & one STD that had WOT fuel starvation after installing an electric DanMark, both have been removed and bike runs top notch now. I think the Pingle and the DanMark together restrict the flow too much. YMMV

[theredark]

I guess the easier way to start would be try it without the fuel valve and stock petcock and it that doesn't fix it try it with a pingle and no fuel valve.  The battery is new right before I put it away (OEM Yuasa).  This problem was masked most of the season by a bad petcock.  I had used an aftermarket diaphragm only kit and the valve in the cover was all gummed up so I ended up replacing that as well with an oem kit.  It's not a big problem just annoying.  Thanks all for the quick response.