Bad Cranking Issue - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Where does this wire go?
Includes Electrical mods, Lights, Stator,
Rectifier, Diagrams, etc

LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old 09-29-2013, 11:43 AM Thread Starter
Join Date: Mar 2012
Location: Fresno, CA
Posts: 96
iTrader: (0)
Bad Cranking Issue

Ok well after doing a FULL rebuild on my engine, i made the mistake of doing the valve timing wrong on the rear cylinder it was off 180 on the camshaft i fixed that issue and gave the engine a lil starting fluid through the filter pods and it fired right up idle was perfect and both cylinders firing good! I would shut it down and fire it up a few times like 5-6 times and all was good!! Had great power as well! I even rode it around the block a few times and all was good! I WAS HAPPY!! Parked it for about 40 mins and cleaned the garage, then when it came time to pull it in for the night from the driveway i had a slow crank issue and no start.. I have already replaced battery with AGM BIG CRANK 220 cca battery, new starter solenoid, cleaned and checked all grounds, even replace the main starter cable with a bigger gauge wire, took apart start switch and cleaned the spider webs out of there, and even bought a rebuild starter from a website! This is what happens while cranking..ill leave it on the battery tender plus (10 years old unit) until the red light shuts off and goes green..the voltage at the battery will be around 13 volts static (even had new battery tested and its got 214CCA's ..and when I crank the engine it'll eventually drop to a minimum 10 volts or so and the very first few cranks sound good then it starts dying down (like rumm rummm rummmm) and then it'll just get weaker and weaker with lowest voltage drop down to about 7.8 volts at the battery while cranking! Also the engine will give a loud backfire while cranking! Scares the SHI* outta me!! I have the peacock on reserve with more than half a tank of gas, new peacock as well I've tried various choke positions and still nothing..I've spent all day yesterday trying to figure this thing out i just want it to run again and i don't understand what happen from the time i parked it for about 30-40 mins! Im on the verge of taking it in to the shop but I'm hoping someone here can lead me in the right direction..i also have a hid system and voltmeter installed not sure if those item will help contribute to the slow cranking...and also does this backfiring that happing intermittently during cranking can this mess up my newly rebuild engine cause if so i don't wanna keep trying to start it until i know for sure what is going on..
Arob559 is offline  
Sponsored Links
post #2 of 4 (permalink) Old 09-29-2013, 12:32 PM
Senior Member
Spockster's Avatar
Join Date: Nov 2012
Location: WV
Posts: 6,875
iTrader: (5)
With that much voltage drop, the coils can't be getting enough power, probably causing the backfire. But I can get backfire just by cracking the throttle open on a hot start. So either fuel and spark being off can lead to backfires.

Can you get it to start again with starting fluid? If so, then are the carbs clean? Could be clogged in the idle circuit or pilot jet? Maybe had some dirt in the bowls that set up in the jets after you shut it down?

Need to also find why it has such a large voltage drop, that's definitely not helping. Have to wonder if the load test on the battery was accurate. Or is the new starter dragging?

The backfire can't really hurt much, could melt an air filter I suppose after enough of it, for long enough. But a bang here and there won't do much.

Might pull the cover and look at those pickup cols, just to make sure everything is still attached right, gaps haven't slipped, etc.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual:

Owner's Manual:
Spockster is offline  
post #3 of 4 (permalink) Old 09-29-2013, 03:08 PM Thread Starter
Join Date: Mar 2012
Location: Fresno, CA
Posts: 96
iTrader: (0)
The voltage drop is whats botherin me most! How do you determine if the starter is dragging?? Maybe i got a bad rebuild?
Arob559 is offline  
post #4 of 4 (permalink) Old 09-29-2013, 08:07 PM Thread Starter
Join Date: Mar 2012
Location: Fresno, CA
Posts: 96
iTrader: (0)
Figured it out!!!! My idler gear that the starter splined to had the big washer on the rear instead of the front causing the gear to bind against the case!!! Now i have to just wait on a new side cover gasket 3-5 days so until then ill just shine up all the chrome lol!
Arob559 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