Bike surging/stumbling at cruising speeds [Archive] - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums

: Bike surging/stumbling at cruising speeds


rbarrett49
03-31-2007, 04:08 AM
Having issues when cruising under constant throttle--the bike seems to surge or stumble (not sure which word best describes). When I first bought the bike a few months ago I noticed that occasionally while riding the freeway the bike would feel like the power was cutting out very briefly--only happened when maintaining speeds, not accelerating. Now the problem is happening every time I ride.

The problem sounds very similar to Johnboy750's problem, but my bike has never come close to dying and has never been hard to start. Same problem, same solutions?

Thanks for the help.

Ryan

93VN750
03-31-2007, 08:32 AM
Ryan -

Let us know the basics on your bike. Is it 100% stock? If not, what changes have been made?

First off, run a couple of tanks treated with Seafoam through it to clear any clogged passages in the carbs.

Jon

Crobins365
03-31-2007, 12:30 PM
I'd check the carb vent hose (runs to the right air box) as well - that seems to be a constant problem. Clearly a "designer flaw", but the hose often gets closed off against the inside of the box. Starves the carbs for O2.

JohnBoy750
04-02-2007, 05:34 PM
Well Ryan welcome to the club!? *^&()%)*%#&%

I feel your pain man. Not that it probably matters at this point but my bike is not a 100% stock. There have been pipes added from the stock baffles back, in other words the front half is stock, the back half is not. My buddy/previous owner added chrome pickup truck pipes. I doubt he ever had it rejetted but at the same time I don't think that's the issue.

I'm at the point of a few full treatments of SeaFoam.

Good luck and pllleeeeaaasseee let us know of your progress.
:rockon:

hyperbuzzin
04-03-2007, 04:55 AM
My buddy/previous owner added chrome pickup truck pipes.

That's the same thing Beavis (from the Y! group) did.
You can check out his pics HERE (http://www.fortunecity.com/bennyhills/radner/499/), along with his other mods.

JohnBoy750
04-04-2007, 01:59 PM
Yeah my pipes are not welded in though just added on. I'm pretty sure they are just held in by a couple of screws. It sure makes for a unique sound, I like it though.

nachos4life
04-04-2007, 03:39 PM
i had a very similar problem awhile back and seafoam got rid of it. hope it works for you.

rbarrett49
04-22-2007, 01:58 AM
Well, the problem is fixed. I found the carb vent hose and rerouted it, made sure that all of the vacuum lines were connected solidly and bingo! Runs great, pulling hard and no hesitating!

For the others that might be facing this problem, try running the tank on reserve and see if that doesn't help. It is feasible that the "ON" hose inside the tank could be partially plugged and cause the same symptoms.

Thanks to everyone for all the help!

jprather
05-17-2007, 12:26 PM
I have been having some of the same problems, was the stumbling/surging my prevelant on one side, or equal on both sides, i guess what i am asking is could you hear a difference on the exhaust sound? mine is doing the same thing but only on the left side ( rear head ).
and was there a lot of backfiring associated with this?

jerry