Old school thinking - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
VN750 General Discussion

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 03-28-2010, 09:34 PM Thread Starter
Junior Member
 
Join Date: Mar 2010
Location: Robertsdale Al
Posts: 9
iTrader: (0)
 
Old school thinking

I was taught that as long you had compression, spark and fuel your motor would run...maybe not well, but run. Me experience with Vulcans (I have owned 2 1500's) is that they will not start unless the battery has a full charge. I have 140psi compression. I have a full charge on the battery. I put a tester on the plugs (all 4)to check for spark. The bike ran for about 15-20 seconds. Shut the bike off. It refuses to give me even a cough. What am I missing? I do not have enough experience with ignition boxes to trouble shoot them. A friend suggested bad coils but both going bad at the same time? Please Help...Cosmo
Cosmotg is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 03-28-2010, 10:03 PM
Old Truck Junkie
 
niterider's Avatar
 
Join Date: Jul 2007
Location: Roby Texas
Posts: 4,133
iTrader: (15)
 
How about the ignition switch. Try wiggling the key.

02 honda sabre 1100
niterider is offline  
post #3 of 10 (permalink) Old 03-28-2010, 10:10 PM
Sparky!!!
 
slimvulcanrider's Avatar
 
Join Date: May 2008
Posts: 8,695
iTrader: (3)
   
Garage
second motion on the iggy switch... its a common problem with our bikes. Another comon problem is the stupid side stand switch...
slimvulcanrider is offline  
 
post #4 of 10 (permalink) Old 03-28-2010, 10:36 PM Thread Starter
Junior Member
 
Join Date: Mar 2010
Location: Robertsdale Al
Posts: 9
iTrader: (0)
 
I must have left something out. The starter turns and I am getting spark. I checked the kickstand switch and the ignition switch. As a matter of fact I checked all safety circuits. If I had a problem with the ignition switch would the starter still turn and would the coils still send spark to the plugs? Please explain....Thanks Bob
Cosmotg is offline  
post #5 of 10 (permalink) Old 03-28-2010, 10:49 PM
Sparky!!!
 
slimvulcanrider's Avatar
 
Join Date: May 2008
Posts: 8,695
iTrader: (3)
   
Garage
ok nm... If you have good spark, then that rules out the iggy switch, saftey switches and kill switch. Wouldn't be coils if you have spark. hows the fuel flow? kinked Vacuum line from carb to tank, fule lines good, are the carbs full of fuel?
slimvulcanrider is offline  
post #6 of 10 (permalink) Old 03-28-2010, 11:25 PM
Member
 
lostboy1975's Avatar
 
Join Date: Feb 2010
Location: indiana
Posts: 37
iTrader: (1)
 
check the safety switch behind the clutch lever. mine went out last year and i played hell trying to figure it out.
lostboy1975 is offline  
post #7 of 10 (permalink) Old 03-29-2010, 02:32 AM
Sparky!!!
 
slimvulcanrider's Avatar
 
Join Date: May 2008
Posts: 8,695
iTrader: (3)
   
Garage
Quote:
Originally Posted by lostboy1975 View Post
check the safety switch behind the clutch lever. mine went out last year and i played hell trying to figure it out.
This problem will cut out the spark as well as the side stand switch and neutral safety switch, emergency kill switch and all the other safety devices on the bike... This problem almost has to be Fuel related. Spark is Good, Compression is Good, then next would be Fuel... although...how do those air filters look?
slimvulcanrider is offline  
post #8 of 10 (permalink) Old 03-29-2010, 08:39 PM
Members who have donated towards server costs
 
Join Date: Nov 2007
Location: Chandler, Arizona
Posts: 3,016
iTrader: (0)
 
Ok, just for reference, you are missing something. It takes FOUR things to make an engine run. Fuel, compression, and a spark AT THE RIGHT TIME. Your ignition timing has to be pretty close. A spark during the exhaust stroke is pretty worthless, even though a lot of engines have one.

But those are just the basics. It gets a lot more complicated. You have to have almost exactly the right air/fuel mixture, a really good spark (at the right time), the starter has to turn the engine over fast enough, ect. Some engines are very temperamental about starting, because their design puts them on the outer margins for what is needed to start and run, so there is no room for any errors, everything has to be perfect. Other engines are much better designed, and have more room for variance.

My new EX500 starts so fast you never even here the starter. My Vulcan 750s, both of them, have to be turned over several times before they will start, and have always been that way, since new. I will try the iridium plugs next time I change them, but spark, compression, air/fuel, and timing seem to be fine. But, that is checking the spark outside the engine. It may not be nearly as good under compression.


Also, I have always removed the clutch and sidestand switches from every single bike I've ever owned that had them, after having had one fail. I leave the engine cutoff switch, but if it failed, I would probably not replace it. I have never needed one on a streetbike. Jerry.

I am a motorcyclist, NOT a biker.


1997 Vulcan 750, purchased about a week ago
2006 Sportster 1200 Low
2013 Royal Enfield Bullet 500, converted to carb
2001 Yamaha XT225, heavily modified
2004 Honda Rebel 250
1979 Vespa P200E
2002 Vulcan 750 parts bike
1994 Yamaha XT225 parts bike
VN750Rider/Jerry is offline  
post #9 of 10 (permalink) Old 03-29-2010, 08:53 PM Thread Starter
Junior Member
 
Join Date: Mar 2010
Location: Robertsdale Al
Posts: 9
iTrader: (0)
 
Your right! Got the bike started and running for about 30secs today. Looks like the starter is drawing a lot of amps. I will take it off and have it tested tomorrow. Also found a wire (Black/Yellow) in the harness not hooked up. I posted a picture in the electrical section because I can not find where it goes. I am encouraged that it runs and will try to eliminate problems until it runs right. Timing of course may be another issue but since it sounded good. Thanks for the input...Cosmo
Cosmotg is offline  
post #10 of 10 (permalink) Old 03-30-2010, 07:02 PM
Linkmeister Supreme
 
OlHossCanada's Avatar
 
Join Date: Aug 2008
Location: Lethbridge, Alberta, Canada
Posts: 7,960
iTrader: (8)
   
Quote:
Originally Posted by Cosmotg View Post
Your right! Got the bike started and running for about 30secs today. Looks like the starter is drawing a lot of amps. I will take it off and have it tested tomorrow. Also found a wire (Black/Yellow) in the harness not hooked up. I posted a picture in the electrical section because I can not find where it goes. I am encouraged that it runs and will try to eliminate problems until it runs right. Timing of course may be another issue but since it sounded good. Thanks for the input...Cosmo
There is a black/yellow wire for a ground running to many electrical components on the bike.

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
OlHossCanada 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