starving at wide open throttle

[theredark]

Good morning all,

Continuing my wide open throttle problem on a 2000 I/S.  Bike runs smooth, idles great but... at wide open throttle it feels like not enough gas getting to carbs,  it accelerates but slowly and with a stutter.  If I back down on throttle it will stop.  I've run a tank full of techron (1/2 bottle) through it and will put the 2nd half in today.  I changed out the original vacuum petcock for a non vacuum pingel.  Changed fuel lines making sure no extra length to hang up.

The engine has not been desmogged but I did change pair valve and vacuum lines last year.  I'm also running a dan-mark solenoid valve.  Air filter looks good.  Any thoughts on where to go next?  I hate the thought of taking it to the stealership but am stuck.

Brad

[Bone]

You have a good looking air filter how many miles on that filter ? Sometimes the little things are the problem.

[Blackduck]

When did this problem start? After any work on it?
Try removing the Dan Marc and see how it runs. Check for any kinked lines .
Has the air box been altered? Is it a stock air filter or K&N?

[R J]

We just had a posting where they had modified the airbox.    Is this the same one?

Dan Marc solenoid.    

1st thing I would do is look for a kink in the hose either in front of behind the solenoid.

2nd thing: Is the Dan Marc on the same level as the rest of the line or does it lay lower in the line.  

Remember, you DO NOT have a fuel pump, so it is all left up to gravity.   If ya come off the tank, at one height and the hose off the Dan Marc or the Dan Marc is lower & then the hose rises, dat be your problem.     The line can be lower, but it can not raise it back up, you are not getting a good flow if it does.

Hope ya can understand what I'm saying.

Think of this as your gas line layout.

____Gas______-----------_____line_________      That raise '---------' can not be allowed in the line.

[Patrick]

I agree that it certainly sounds like a fuel delivery issue..  If the only modification/change to the induction system or fuel system is the electric solenoid then that is where I would look.. There have been several similar complaints over the years about the installation of that valve..

[John Schmidt]

Yes, other posts are on target....the fuel line has to run downhill all the way from the petcock to the "T."  Without disturbing anything, use a mirror and flashlight to check the alignment of the fuel line. If there is any droop whatsoever, it will starve for fuel at higher rpm....especially when the tank gets low. Then it doesn't have as much "fuel weight" pressing down on it.

[indybobm]

Had the same problem on my Valk when I got it. Anything above 3000 RPM, it acted like someone was turning it off and on very quickly. Ran a can of Berryman B12 through it and the problem was solved. Actually, I noticed an improvement almost as soon as I started it up. Think the problem has something to do with the needles that move up and down in the main jets. I tried Seafoam, Techtron, Lucas, plus a coule of others. Each one did a litlle but when I put in the Berrman's it was unbelievable the difference it made. One whole can ($3.72 at Autozone) and then filled the tank.

[Hoser]

Reposition or remove that danmark.  Hoser

[JC]

Reposition or remove that danmark.  Hoser

+1   

[theredark]

I'm hoping you all are right.  I looked at the hose last night and there is a small rise after the solenoid up to the tee and then down to each set of carbs.  I think I will have to reposition the lines to run under the #16 air supply hose (from manual).  Right now it crosses above it.  Just didn't have it in me last night to tackle the airbox although I am getting better at it!

[John Schmidt]

Reposition or remove that danmark.  Hoser

Don't be so quick to blame it on the Danmark. I've had mine in for approx. 5 yrs. with no trouble whatsoever, but when I installed everything I made certain it was all "downhill."

[MP]

Have had NO trouble with the Danmark on my sidecar rig, and I have to go at almost full throttle, all the time!!!

I did however, have to take the quick disconnect off.  That did not work.

MP

[theredark]

Thanks to all for the advice.  The problem I think was actually two.  There was a slight up loop from the dan-mark to the tee then down to each carb.  I routed the fuel line under the air hose,  shortened up the lines from the tee and it's definintely all down hill.  I also found that when I had installed velocity stacks last year one of the carb covers underneath was not seated fully causing a leak.  I also put in some Berryman cleaner just to cover all my bases, about half a can to a full tank of fuel.  Thanks again,  Brad