The popping while revving down is from lots of gas sucked through the system and not being burnt. This is somewhat normal, esp. on race vehicles. In your case, you might need the carbs to be reset/adjusted (synced). Before mine were done, it would surge because one or more carbs were putting out more gas than the others. when those cylinders fired, it would raise the RPMs, then die down as the others fire. the RPMs would hang a little when you blip the throttle, and the throttle response was weak.
start by resetting the pilot (idle) screws to between 2 and 3.5 turns out from bottomed-out. Adjust the idle. My bike ran 1000 times better after just this was done. When I had the carbs off, I set the sync (throttle butterflies) by sight - look through and adjust all so that you see the same sliver of light through the bottom of each one. Then procede with the proper sync procedure using a manometer (if you've got one) - if not, do what I did before putting the carbs on the bike and you should notice a big improvement. On Jul 10, 2011, at 2:56 PM, Kim Paddock wrote: > It surges all of the time. The exhaust pops when it's reved up and during the > deceleration that follows. I have looked at the plugs. > > --- On Wed, 7/6/11, Allen Thomas <[email protected]> wrote: > > From: Allen Thomas <[email protected]> > Subject: Re: [Nighthawk Lovers] Engine surge > To: "Nightwawk Lovers" <[email protected]> > Date: Wednesday, July 6, 2011, 12:00 AM > > Does it surge while riding? Does it surge while cold or hot? Does the exhaust > pop while idling or during deceleration? If you blip the throttle do the RPMs > drop below idle then return, do they hang for a bit then lower? Have you > looked at the plugs? > Sent via BlackBerry by AT&T > From: Kim Paddock <[email protected]> > Sender: [email protected] > Date: Tue, 5 Jul 2011 10:58:17 -0700 (PDT) > To: <[email protected]> > ReplyTo: [email protected] > Subject: [Nighthawk Lovers] Engine surge > > Hi all! I have a surge in my engine that I can't figure out. When I start the > bike it revs up and down about 500rpm. I have taken off the carbs and I don't > think that's the problem. Could it be the choke cable? An engine problem? Let > me know your thoughts. Hotrodmamma. > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
