Hesitancy, seems weird - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
VN750 General Discussion

LinkBack Thread Tools Display Modes
post #1 of 23 (permalink) Old 04-30-2006, 06:56 AM Thread Starter
Senior Member
Join Date: Jan 2006
Posts: 226
iTrader: (0)
Hesitancy, seems weird

Hey guys, I'm back with a new question. I noticed my bike is starting to act a little weird. In the past, I used to accelerate from first, shift at 4,000 which drops the rpms to around 3,000, and would often cruise in the city around 3,000 - 3,500 rpms. Now let me tell you what is happening.

I accellerate in first gear. Sudden or gradual, no problems. Upon reaching around 4,000 rpms, I shift to second. RPMs drop to around 3,000 for a moment but rise as I accelerate. 4,000 RPMs is reached again with no trouble and I shift again. Engine drops to 3,000 RPMs. I continue to accelerate. The bike reaches 40 mph at 4,000 RPMs or so in 3rd gear. I shift to 4rth gear. Engine drops to 3,000 rpms. At this poing, if I try to accelerate, the bike starts to "jerK" or "surge" or something, and you can hear the engine bog down a bit. If you try to go up even the slightest hill, or have a bit of a wind, you not only won't accelerate, but you might even slow down. You can roll on full throttle but it only feels worse and starts to bog down more.

If you downshift back to 3rd, the bike will continue to accelerate. If once you reach about 5,000 RPMs, you shift back to fourth, the rpms drop to 4,000, and the hesitancy is mostly gone, and it goes away as engine speed increases. Whats the problem? Like I said, I have no trouble with this in gears 1, 2 & 3. Idle is good and strong, with no problems there. I have not really looked to see what happens when I try to shift to 5th at 3,000 RPMs. This problem has come in sort of recently. Nothing was done to the bike, e.i. I didn't modfy anything, do anything, no accidents etc since before the problem showed itself to after it came up. I checked fluids and it all seems good. Can anyone help me?

InsuredDisaster is offline  
Sponsored Links
post #2 of 23 (permalink) Old 04-30-2006, 12:11 PM
Join Date: Sep 2005
Posts: 169
iTrader: (0)
Things you can check:

1. Spark plugs "new or old"?
2. Add SeaFoam to the gas "get it at Napa Auto Parts"
3. Fuel/air mixture screw "has it been back out to 2 1/2 turns on the carbs?
4. Check carb boots and make sure they are tight.

Those are some things you can check for now.
whistle clean is offline  
post #3 of 23 (permalink) Old 04-30-2006, 02:05 PM Thread Starter
Senior Member
Join Date: Jan 2006
Posts: 226
iTrader: (0)
Carb boots are a good idea. I'll try that. I'll also get the sea foam. Figure those things are cheap and easily done. Thank you so far.

InsuredDisaster is offline  
post #4 of 23 (permalink) Old 05-01-2006, 10:26 AM
Uber Member
Join Date: Feb 2006
Location: Dallas, TX
Posts: 1,280
iTrader: (0)
Send a message via AIM to Hizzo3 Send a message via Yahoo to Hizzo3
sounds like a carb issue to me.....try the sea foam...

'04 Vn750
Currently Installed
nat'l cycle deflector shield
westco 12v30 MF, 30A/h w/ 350 CCA's w/ custom box
TOC stator cover w/ Frankenstator mod!
R/R relo

Soon to have (own or on order)
Mez's 110-FRT 170/80-Rear
Custom rear fender and tail light
Givi hard bags w/ custom rear turn signals

Band Engineer/Webmaster for Josey Contreras Tejano Band
Hizzo3 is offline  
post #5 of 23 (permalink) Old 05-02-2006, 03:04 PM Thread Starter
Senior Member
Join Date: Jan 2006
Posts: 226
iTrader: (0)
Yeah, I just got some today. I poured it in the gas tank. I'll let you know how it works out. Thanks for your help.

InsuredDisaster is offline  
post #6 of 23 (permalink) Old 07-16-2006, 03:34 PM
Join Date: Jul 2006
Posts: 124
iTrader: (0)
pretty much this same thing is happening to me this weekend with my 86 vulcan.. all is good until i am in 5th gear then it starts surging and lurching while i am holding a contstant throttle. if i really give it some throttle it usually does fine but when i am just cruising along its surging and lurching.
yesterday before this problem was happening i had just changed the oil and the gear oil and put some seafoam in the tank and fille dup. it was after that when this started happening. you think the seafoam knocked some crud loose or something? why would it only act weird in 5th gear?

nachos4life is offline  
post #7 of 23 (permalink) Old 07-16-2006, 03:44 PM
Once Banned
cegodsey's Avatar
Join Date: Jun 2006
Location: Bryant, Arkansas
Posts: 2,125
iTrader: (0)
Ben - Only 4th gear? That DOESN'T sound like a carb problem. Carbs don't care what gear you're in. That sounds like a transmission problem.

2000 A16
Drilled baffles
$65 leather saddle bags
Kuryaken grips
relocated R/R
25,000+ original owner miles
cegodsey is offline  
post #8 of 23 (permalink) Old 07-16-2006, 05:19 PM
Join Date: Jul 2004
Posts: 206
iTrader: (1)
When mine was doing this...turned out to be the vaccum line that goes to the RH air cleaner. I had replaced it during the rebuild and effectively plugged it by pushing it in too far. How to fix? Pull off RH air cleaner...cut end of tube at a diagonal...reassemble and test.

I wish I understood why this particular vacuum line has this effect...I don't understand, but it does. Can't hurt to try, right?
Imnohero is offline  
post #9 of 23 (permalink) Old 07-16-2006, 08:20 PM
Join Date: Jun 2005
Posts: 198
iTrader: (0)
Could this be the clutch slipping a little bit?
Dan is offline  
post #10 of 23 (permalink) Old 07-16-2006, 09:03 PM
Join Date: Jul 2006
Posts: 124
iTrader: (0)
Originally Posted by Dan
Could this be the clutch slipping a little bit?
is there a fix for this or just a replacement?
nachos4life is offline  
Sponsored Links


Quick Reply

Register Now

In order to be able to post messages on the Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Once registered, your User Name"cannot be changed". We can make exceptions within 7 days, but after that, it is set in stone.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome