Problem going over 30 - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
VN750 General Discussion

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old 04-06-2010, 01:35 PM Thread Starter
Member
 
supasamurai's Avatar
 
Join Date: Apr 2009
Location: NOLA
Posts: 34
iTrader: (0)
 
Problem going over 30

I just woke my bike up after the winter and it's having a really hard time getting up over 30. It seems to rev up just fine when it's not in gear, but when it is in gear, it bogs down if I try to go over like 3k rpms. I suspect a vacuum problem, maybe the tranny is a vacuum assisted type or something and when it's in gear it's running into a vacuum leak somewhere? Anyone had a problem like this before?
supasamurai is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old 04-06-2010, 04:02 PM
Member
 
Join Date: Feb 2010
Location: Essex
Posts: 76
iTrader: (0)
 
Issues with poor running after a winter lay up are not uncommon, especailly for North Amrican riders. It is most likely to be some form of dirt or contamination in the fuel supply somewhere (what do they put in your petrol over there?). Prevention is always better than cure but having not done that the best/easiest solution without taking the bike to pieces appears to be an application of Seafoam as directed on the can.

Mine is a Red one.
Colour matched Bungee straps
essexboi is offline  
post #3 of 18 (permalink) Old 04-06-2010, 04:08 PM
Members who have donated towards server costs
 
flitecontrol's Avatar
 
Join Date: Dec 2008
Location: Monroe, LA
Posts: 4,706
iTrader: (14)
 
Did you put fuel stabilizer in the gas and let it get into the carbs before you parked it?

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 #4 of 18 (permalink) Old 04-06-2010, 04:17 PM Thread Starter
Member
 
supasamurai's Avatar
 
Join Date: Apr 2009
Location: NOLA
Posts: 34
iTrader: (0)
 
Quote:
Originally Posted by essexboi View Post
Issues with poor running after a winter lay up are not uncommon, especailly for North Amrican riders. It is most likely to be some form of dirt or contamination in the fuel supply somewhere (what do they put in your petrol over there?). Prevention is always better than cure but having not done that the best/easiest solution without taking the bike to pieces appears to be an application of Seafoam as directed on the can.
I am seafoaming, yes. Also, it had the same problem before I parked it. I bought it used and without a carburetor, so I put a new (used but freshly rebuilt) carb in and then parked it. So why does it stumble when I'm in gear, but not when I'm in neutral?

Last edited by supasamurai; 04-06-2010 at 04:19 PM.
supasamurai is offline  
post #5 of 18 (permalink) Old 04-06-2010, 04:38 PM
Member
 
Join Date: Feb 2010
Location: Essex
Posts: 76
iTrader: (0)
 
Assuming it is a fuel problem then it will be a simple matter of the volume getting through, or not. When not in gear the engine needs very little fuel to run so a small restriction may not even show. As soon as you start to load the engine the amount of fuel you need rises dramatically and any problems with delivery will soon appear.

Now we know you have "been at the carbs" it becomes even more likely that this is your problem. If the Seafaom does not cure it then you will be looking at things like your vacuum hoses and various other fittlngs to make sure everything is on correctly and there are no kinks in the bends or leaks at the joints. After that it may be time to start taking it apart but for now just make sure as best you can it is together in the way it should be.

Have you made any of your own pipes and hoses for it or did you use stock parts?

Mine is a Red one.
Colour matched Bungee straps
essexboi is offline  
post #6 of 18 (permalink) Old 04-06-2010, 09:58 PM Thread Starter
Member
 
supasamurai's Avatar
 
Join Date: Apr 2009
Location: NOLA
Posts: 34
iTrader: (0)
 
Quote:
Originally Posted by essexboi View Post
Have you made any of your own pipes and hoses for it or did you use stock parts?
Humm, could it be the cheap lawnmower fuel lines i used to replace the cracked stock ones? I wonder if they're just collapsing when i gas it.

Last edited by supasamurai; 04-06-2010 at 10:00 PM.
supasamurai is offline  
post #7 of 18 (permalink) Old 04-07-2010, 12:43 AM
and the Adventure Cycle
 
hyperbuzzin's Avatar
 
Join Date: Jun 2004
Location: Western PA
Posts: 6,138
iTrader: (1)
   
Have you checked the air filters?
Might not be that there's not enough fuel, but too much air if they are disintegrating/old.


AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC


"When life throws you curves,
Aim for the apex."

Author Unknown
hyperbuzzin is offline  
post #8 of 18 (permalink) Old 04-07-2010, 09:10 AM
Member
 
Join Date: Feb 2010
Location: Essex
Posts: 76
iTrader: (0)
 
Quote:
Originally Posted by supasamurai View Post
Humm, could it be the cheap lawnmower fuel lines i used to replace the cracked stock ones? I wonder if they're just collapsing when i gas it.
It may be.

I once had an old VT500 which I commuted into London every day. Bits wore out and I got it a new(??) set of carbs from a CA spec bike and after messing about taking all the rubbish off reassembled it but had to make some new fuel pipes from my bits box. The bike ran with no problems at all unless I wanted to go over 50 for more than a mile, at which point it would act like it was running out of fuel. Slowing down to 40 for a few seconds cured it but as soon as I went over 50 again the problem would reappear.

It turned out that I had cut one pipe a quarter of an inch too long and when I bolted everything together a small kink would happen. Not enough to stop it running at urban speeds but just enough restriction in the fuel flow to make higher speeds an issue. It seems I am not the only one this has happened to, so check yours carefully. It may well be just a quarter of an inch too much tube in the wrong place.

Mine is a Red one.
Colour matched Bungee straps
essexboi is offline  
post #9 of 18 (permalink) Old 04-07-2010, 04:55 PM
Senior Member
 
bj31702's Avatar
 
Join Date: Jun 2007
Location: Ashtabula, Ohio
Posts: 321
iTrader: (0)
 
Send a message via Yahoo to bj31702
Quote:
Originally Posted by supasamurai View Post
I am seafoaming, yes. Also, it had the same problem before I parked it. I bought it used and without a carburetor, so I put a new (used but freshly rebuilt) carb in and then parked it. So why does it stumble when I'm in gear, but not when I'm in neutral?
Just throwing something out there. Have the carbs been sync'd?

'09 Nomad e sold
'85 VN700 A1 (needs work)
'11 Voyager
bj31702 is offline  
post #10 of 18 (permalink) Old 04-07-2010, 05:12 PM
Old Twistie Sticks Rider
 
Old Dog's Avatar
 
Join Date: Aug 2007
Location: Country Created by Geniuses, But Run by Idiots...!!!
Posts: 5,072
iTrader: (2)
 
Is the Carb. vent line cut on a 45* into the filter box, could it be jambed in and blocked...?????????
Have a good one...Old Dog...

Southern Central Tennessee.......
Now on the Dark Side......
Girl's Bike 09 Sporty xl 1200 Custom...33k + & clickin......
Sportster Owner/Rider since age 72...lol... Rider since Simplex...???
09-xl1200 "C" Vivid Black, Cast wheels w/19" Frt., SE-Stage 1+, X14iEDs...
MicroTach +, Higher wider H-bars, GPS Mt., Mustach bar Hwy. pegs...
Viking Shock cutout Saddlebags, Rear Mt. Signal Lt. Kit, Fork Brace...
RoadKing Air Shocks, Mustang Seat, Progressive Fork Springs...
Old Dog 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