Losing power at speed, eventually stalling - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Carbs and Fuel System
From the gas tank to the carbs
All fuel system discussion

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 49 (permalink) Old 02-25-2010, 01:39 PM Thread Starter
Junior Member
 
Join Date: Jan 2010
Location: Charleston, SC
Posts: 27
iTrader: (0)
 
Losing power at speed, eventually stalling

This has happened a couple of times, now:

Riding along happy as a clam (first time at 55mph, the second at 70), when it starts hesitating and eventually there's no power at all. Pulling over, the bike eventually dies and will not start.

After 10 minutes or so, it starts up just fine.

It appears to be a carburetor issue. It's an old bike ('85 VN700) and could prolly do with a full blown carb work-over and clean. I've seen a few threads about problems similar to this. I'm running a bit of seafoam in the tank - maybe a quarter bottle per tank.

However, here's the thing I don't understand. When it dies, the gear change lever just won't do anything: It doesn't appear to change gear back to 1st (or go up in gears either, which I'd expect), and it won't hit neutral. After sitting for 5 minutes, I can put it in neutral - that is, the neutral light comes on. It won't start at this point; a few more minutes later and it'll start.

So, I'm sure there's a couple of carb things I can work on, but why the 'gear change' issue (not being able to put it in neutral)? Is there a 'link' I'm not thinking of?

Last edited by OceanTwo; 02-25-2010 at 01:40 PM. Reason: title was a bit misleading
OceanTwo is offline  
Sponsored Links
Advertisement
 
post #2 of 49 (permalink) Old 02-25-2010, 02:13 PM
Members who have donated towards server costs
 
flitecontrol's Avatar
 
Join Date: Dec 2008
Location: Monroe, LA
Posts: 4,699
iTrader: (14)
 
Sounds like possibly more than one issue. The bike dying sounds like the "phantom out of gas syndrome", which I believe is related to insufficient venting of the fuel tank. If you open the tank cap and can start it back up again immediately, it's probably vent related. Clean the vent hole, which is near the cap hinge, with a pipe cleaner.

Not sure what is going on with the shift issue and how it may be related to the hesitation/dying.

I'm keepin' all the left over parts. I'm gonna use 'em to build another bike!
_____________________________________________
"Black Beauty"
1989 VN750 acquired December, 2008, 6,711 miles
Currently 23,298 miles

Old Blue
2001 Honda CMX250 Rebel acquired July, 2008

1987 VN750 project bike, acquired August, 2009, 33,000 miles and balancer sticking out of the case, currently awaiting attention and parts
flitecontrol is offline  
post #3 of 49 (permalink) Old 02-25-2010, 03:53 PM
Senior Member
 
Chavisimo's Avatar
 
Join Date: Sep 2009
Posts: 308
iTrader: (0)
 
When it dies again, try pulling in the clutch and move the bike forward while trying to shift.


VROC Number: 31246
2003 Kawasaki VN750 SOLD
2006 Honda VTX1800C
Chavisimo is offline  
 
post #4 of 49 (permalink) Old 02-25-2010, 10:57 PM
Linkmeister Supreme
 
OlHossCanada's Avatar
 
Join Date: Aug 2008
Location: Lethbridge, Alberta, Canada
Posts: 7,960
iTrader: (8)
   
Quote:
Originally Posted by flitecontrol View Post
Sounds like possibly more than one issue. The bike dying sounds like the "phantom out of gas syndrome", which I believe is related to insufficient venting of the fuel tank. If you open the tank cap and can start it back up again immediately, it's probably vent related. Clean the vent hole, which is near the cap hinge, with a pipe cleaner.

Not sure what is going on with the shift issue and how it may be related to the hesitation/dying.
I don`t recall anyone using a pipecleaner ,fc. I haven`t looked into mine yet, but I think the recommended method is to remove the gas cap and use a TINY TWIST DRILL BIT, to ever so slightly enlarge the vent hole.

EDIT: Try cleaning the vent by spraying some aerosol wd-40 through at the gas cap, and watch for it to drip from rubber hose down near the rear tire. Compessed air could also be tried.

I`m sure someone who has performed this little operation will chime in with the particulars.

To confirm the "Phantom out of Gas Syndrome", put an extra key in the gas cap (or not, `85 model may not have key lock in gas cap). When the engine starts to die, open gas cap to relieve vacumn in tank. If the engine regains power, you have identified the problem. The better part is, the fix is quick, easy and no/or low cost.

Gordon

1991 VN 750 -"Cosmic Lady" or "Bad Girl"?
Purchased May 16, 2008
Approx.19,300km (12,000 miles)

H-D windshield
Relocated R/R
MF-AGM battery
Fiamm Freeway Blaster horns
F&S luggage rack and engine guard
Kury Offset Hiway pegs
July 13, 2016, Riding on the DARKSIDE now, Classic Radial 165/80-15


TOP TEN THINGS A NEW RIDER/OWNER SHOULD DO. Click on link.
https://www.vn750.com/forum/11-vn750-general-discussion/9127-top-ten-items-you-would-suggest-new-owner-do-his-new-ride.html

Last edited by OlHossCanada; 06-19-2010 at 08:22 PM.
OlHossCanada is offline  
post #5 of 49 (permalink) Old 02-26-2010, 08:28 AM Thread Starter
Junior Member
 
Join Date: Jan 2010
Location: Charleston, SC
Posts: 27
iTrader: (0)
 
I tried opening the gas cap, just after it stalled, the second time. Unfortunately, it didn't allow the bike to start. It may be that the bowls were not full enough yet (it was about 8 or 9 minutes before it would start).

[The gear change thing: I now recall when doing the spline lube and gear change pawl spring replacement, having the front bevel gear casing off that the gearbox/splines needed to be in a certain position for it to actually change gears - so, I think a red herring, here].

I'll try the vent tube clean, but the gasket on the tank doesn't appear to hold a very good seal, anyway, so am not convinced this will solve the issue. It's a cheap fix if it does, though.
OceanTwo is offline  
post #6 of 49 (permalink) Old 02-26-2010, 09:44 AM
Senior Member
 
Join Date: Apr 2009
Posts: 209
iTrader: (2)
 
hmm, i've had that problem too. in the case my engine wont start on me i cannot shift out of 1st or Neutral. so i cant seem to do a proper rolling start.

do a carb clean out. i bet your jets are clogged.
6204 is offline  
post #7 of 49 (permalink) Old 02-26-2010, 10:12 AM
Members who have donated towards server costs
 
flitecontrol's Avatar
 
Join Date: Dec 2008
Location: Monroe, LA
Posts: 4,699
iTrader: (14)
 
Quote:
Originally Posted by OlHossCanada View Post
I don`t recall anyone using a pipecleaner ,fc. I haven`t looked into mine yet, but I think the recommended method is to remove the gas cap and use a TINY TWIST DRILL BIT, to ever so slightly enlarge the vent hole.
Could have sworn I read that tip here, but I've been wrong before!

I'm keepin' all the left over parts. I'm gonna use 'em to build another bike!
_____________________________________________
"Black Beauty"
1989 VN750 acquired December, 2008, 6,711 miles
Currently 23,298 miles

Old Blue
2001 Honda CMX250 Rebel acquired July, 2008

1987 VN750 project bike, acquired August, 2009, 33,000 miles and balancer sticking out of the case, currently awaiting attention and parts
flitecontrol is offline  
post #8 of 49 (permalink) Old 02-26-2010, 11:14 AM
Sparky!!!
 
slimvulcanrider's Avatar
 
Join Date: May 2008
Posts: 8,695
iTrader: (3)
   
Garage
Quote:
Originally Posted by flitecontrol View Post
Could have sworn I read that tip here, but I've been wrong before!
I have heard it too... some one last summer posted the pipe cleaner trick to get dirt and debris out of the hole...the problem isn't that the hole is too small, but rather he hole getting clogged
slimvulcanrider is offline  
post #9 of 49 (permalink) Old 02-26-2010, 05:33 PM
Old Truck Junkie
 
niterider's Avatar
 
Join Date: Jul 2007
Location: Roby Texas
Posts: 4,130
iTrader: (15)
 
Check the vaccuum hose to the carb from the petcock for cracks that can cause it to leak air into it.

02 honda sabre 1100
niterider is offline  
post #10 of 49 (permalink) Old 03-02-2010, 02:19 PM
Member
 
TechMech's Avatar
 
Join Date: Jul 2006
Location: St. Louis, MO
Posts: 46
iTrader: (0)
 
Chiming in on the vaccuum hose from the carb to the petcock: I'm convinced that if the hose is old it gets hard and doesn't make a leak-free connection even if it doesn't have cracks. After many tries, replacing the hose with a new one is the one thing that appears to have fixed my "phantom out-of-gas syndrome" problem.
TechMech is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in










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