Runs rough when I get on the throttle

[FireValk]

My bike runs and accelerates fine unless I really get on the throttle.  I notice the problem most on the highway in 5th gear.  Something seems to be holding the bike back and it shakes a little.  It runs fine if I am just cruising.  Any suggestions?

[Hoser]

If you are crankin the throttle at 50 or below, a little vibration is normal for a short time.  A kick down to 4th will cure it.  Sixty or above shouldn't happen.  This is just a slight vibration, if it's really shakin, there is a problem.

[FireValk]

I get the vibration/shaking above 60.  I can accelerate slowly without a problem but get the moderate shaking when I get on it.  Any ideas where I should start to look?  Maybe synch the carbs?

[Warlock]

I get the vibration/shaking above 60.  I can accelerate slowly without a problem but get the moderate shaking when I get on it.  Any ideas where I should start to look?  Maybe synch the carbs?

Does it sound like the motor is starving for gas? The vibration could be coming from a bad u-joint.
David

[FireValk]

It does almost sound like it might be starving for gas.  I have run 2 tanks of gas with Seafoam through it without any noticable change.

[mmvalk]

RPM?  the bike tends to 'vibrate' a bit when accelearting within the 2500 - 3000 RPM range.  As far as I know, that's normal behavior for a Valk.

[Wago]

My bike runs and accelerates fine unless I really get on the throttle.  I notice the problem most on the highway in 5th gear.  Something seems to be holding the bike back and it shakes a little.  It runs fine if I am just cruising.  Any suggestions?

Fuel valve - probably a bad diaphraghm.  Install repair kit or replace with a Pingel. (test b4 replacing - if the valve won't hold vacuum, repair or replace),
Wago