Pickup Coil Mod Details - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Electrical
Where does this wire go?
Includes Electrical mods, Lights, Stator,
Rectifier, Diagrams, etc

 4Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 05-07-2018, 10:34 PM Thread Starter
Senior Member
 
Join Date: Jul 2017
Location: Sometimes Westchester, sometimes Plattsburgh, NY
Posts: 102
iTrader: (0)
 
Pickup Coil Mod Details

So I plan to try my hand at the pickup coil mod, but I'm not exactly understanding where the 0.020" Gap is supposed to be. I know it's supposed to be against some kind of plate on the stator? On a photograph I saw a "trigger magnet", is this the piece that's supposed to have the 0.020" clearance from the coil, or another?
Also, should the engine be cold, or can I do this after a ride? And which way should I rotate the motor if I have to? Clockwise or counter?
SergheiS is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 05-08-2018, 09:25 AM
Super Moderator
 
Join Date: Feb 2013
Location: SW Florida
Posts: 2,467
iTrader: (5)
 
the trigger magnets on the flywheel are on the outer diameter. the stick up slightly from the surface (very slightly). you set the gap between the coils and the magnets to .020". if I recall, I turned mine counterclockwise when viewed from the left side of engine, where the flywheel and coils live. I did mine when cold.

you will find that you need to elongate at least one mounting hole on each coil, as well as remove the locating tabs that are cast into the cover in order to get the adjustment made. I used a rat-tail file for the holes (be careful, the wires are likely to be fragile), and a small pair of diagonal cutters to snap the tabs off (its just aluminum, and fairly soft there)

2005 VN750

Sold 11-27-17
michiganteddybear is offline  
post #3 of 16 (permalink) Old 05-08-2018, 11:13 AM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,685
iTrader: (5)
   
I think counterclockwise rotation is correct, but it wouldn't hurt to check by bumping the starter with the stator cover removed, just to check.

Overhead cam setups are sensitive to rotating backward, it puts the chain/belt slack on the wrong side of the loop (opposite the tensioner), and could cause problems.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
 
post #4 of 16 (permalink) Old 05-08-2018, 01:20 PM Thread Starter
Senior Member
 
Join Date: Jul 2017
Location: Sometimes Westchester, sometimes Plattsburgh, NY
Posts: 102
iTrader: (0)
 
Did it counterclockwise on a cold motor, and put the coils at 0.020". Started right up for a few seconds, but I'm gonna let the loctite dry, so I'll test it out tomorrow to know for sure how it went. Next in line: 2 wire mod & fixing a broken ground wire.
Thorn and ubertalldude like this.
SergheiS is offline  
post #5 of 16 (permalink) Old 05-08-2018, 05:11 PM
Senior Member
 
Jason Pittenger's Avatar
 
Join Date: Apr 2018
Location: Northern Illinois (Not Chicago)
Posts: 272
iTrader: (0)
 
Garage
Any chance you can measure the ignition timing after the mod?
From what I read, this mod advances the timing, but I didn't see any measurements after the mod.


'89 VN750 Bought stock 4/12/18 @ 17805.9 miles $800. Wrecked once. 27454.5+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB. 110/90 Front Tire. Pick-up coil mod. Shindengen MOSFET FH020AA r/r. USB Outlet + Voltmeter. Repainted Metallic Blue w/ new tank bages. Ear Shave (wo/ coasters) 40/140 NO shims 45MPG. MCCT conversion.

Planned modifications:
Custom LED turn signals. Windshield. Highway Pegs. (Possible) ignition adv. Tuxedo Mod. Ignition coil mod.
Jason Pittenger is offline  
post #6 of 16 (permalink) Old 05-08-2018, 07:14 PM
Super Moderator
 
Join Date: Feb 2013
Location: SW Florida
Posts: 2,467
iTrader: (5)
 
the amount the timing changes is minimal. many (me included) feel like performance is slightly better, but thats just the butt dyno measurement

2005 VN750

Sold 11-27-17
michiganteddybear is offline  
post #7 of 16 (permalink) Old 05-09-2018, 11:36 AM Thread Starter
Senior Member
 
Join Date: Jul 2017
Location: Sometimes Westchester, sometimes Plattsburgh, NY
Posts: 102
iTrader: (0)
 
I will be 100% honest, I'm new to carburetors & distributor systems, so I'm not exactly sure how timing is measured. All I know is, changes in acceleration seem minimal right now, but starting up seems a lot easier, which was always my main problem.
SergheiS is offline  
post #8 of 16 (permalink) Old 05-09-2018, 12:51 PM
Senior Member
 
Jason Pittenger's Avatar
 
Join Date: Apr 2018
Location: Northern Illinois (Not Chicago)
Posts: 272
iTrader: (0)
 
Garage
Quote:
Originally Posted by michiganteddybear View Post
the amount the timing changes is minimal. many (me included) feel like performance is slightly better, but thats just the butt dyno measurement
I have considered messing with the stock timing (5-25 BTDC) to try to get a bit more out of it. Maybe bump it 2 degrees for 7-27 BTDC? Some guy asked the question on another forum 6 years ago, but the thread died.

My truck (I know, I know, vastly different engine...5000CC...V8...Single plug per cylinder...etc) has ignition advance starting at 14 BTDC base timing, with both vacuum and RPM advance on top of that. For the Vulcan to have a base timing of 5 seems like an opportunity for a bump in HP, throttle response and MPG, but it all depends on how close to the edge Kawasaki set it from factory. The dual plugs reduces the need for spark advance.

Quote:
Originally Posted by SergheiS View Post
I will be 100% honest, I'm new to carburetors & distributor systems, so I'm not exactly sure how timing is measured. All I know is, changes in acceleration seem minimal right now, but starting up seems a lot easier, which was always my main problem.
I grew up on Fuel Injection, so I'm learning all this stuff too. Head over to the link I posted above from the other forum, as the 2nd to last post talks about ignition advance theory better than I could write up. The timing measurement is outlined in the Kawasaki service manual on page 272 (if you download the service manual from this thread). It requires a timing light to measure.


'89 VN750 Bought stock 4/12/18 @ 17805.9 miles $800. Wrecked once. 27454.5+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB. 110/90 Front Tire. Pick-up coil mod. Shindengen MOSFET FH020AA r/r. USB Outlet + Voltmeter. Repainted Metallic Blue w/ new tank bages. Ear Shave (wo/ coasters) 40/140 NO shims 45MPG. MCCT conversion.

Planned modifications:
Custom LED turn signals. Windshield. Highway Pegs. (Possible) ignition adv. Tuxedo Mod. Ignition coil mod.
Jason Pittenger is offline  
post #9 of 16 (permalink) Old 05-09-2018, 05:00 PM
Super Moderator
 
Join Date: Feb 2013
Location: SW Florida
Posts: 2,467
iTrader: (5)
 
the problem with changing the timing on the vn750 includes, but is not limited to:

1. designed as non-adjustable.. there is no way to change it without modifying the pickup coil mounting (left cover)
2. all the advance is handled in the igniter module, probably based solely on rpm.
3. with 10 to 1 compression, in order to live happy on 87 octane, you cant have much timing. also one of the reasons we have 2 plugs per cylinder, to light the fire from both sides of the chamber
Spockster and ubertalldude like this.

2005 VN750

Sold 11-27-17
michiganteddybear is offline  
post #10 of 16 (permalink) Old 05-28-2018, 01:48 AM
Senior Member
 
Jason Pittenger's Avatar
 
Join Date: Apr 2018
Location: Northern Illinois (Not Chicago)
Posts: 272
iTrader: (0)
 
Garage
I did the .020" mod yesterday and I honestly didn't notice anything different. Factory gap was .033 on both coils.

I did the math though and moving the coils clockwise by .041-.045" will advance the timing by one degree. The timing module is under the assumption that the pick up will be triggered at a particular position of the crankshaft. My guess is the coils are triggered at or before the maximum advance (25 degree). The module then retards the timing based on rpm (5 degrees BTDC at 1k rpm). The module would be unaware of any manual advance, and would assume it's in the factory position. Since a module handles the timing advance, a manual advance of 1 degree would shift the entire range (5-25 becomes 6-26). Now whether this would result in detonation or not is the real question.

The goal is peak cylinder pressure right after Top Dead Center. It takes a finite amount of time for the pressure to build up. Theoretically, twin spark plugs means it takes half as much time. Too much advance results in either: peak pressure before Top Dead Center, or the pressure builds up to the point that a portion of the yet unburned fuel spontaneously explodes. The first is the hard limit of timing. The second can be resolved through higher Octane fuel.

Having grown up on a low carb diet (all fuel injection cars), I am not well versed at identifying the symptoms of too much ignition advance. I suspect that Kawasaki was conservative from the factory. Is there a possible improvement here, or am I chasing a fools dream?

If I attempt this change, what should I be listening for, and under what conditions are considered "worst case" ?

All the Google results say that too much timing advance can damage an engine. Is this one single rev with 1 degree too much timing and BOOM, or is this sustained operation for 3 hours with detonation? Is it possible to find the limit without causing permanent damage?

If this works, I expect to see an increase in both power AND mpg.


'89 VN750 Bought stock 4/12/18 @ 17805.9 miles $800. Wrecked once. 27454.5+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB. 110/90 Front Tire. Pick-up coil mod. Shindengen MOSFET FH020AA r/r. USB Outlet + Voltmeter. Repainted Metallic Blue w/ new tank bages. Ear Shave (wo/ coasters) 40/140 NO shims 45MPG. MCCT conversion.

Planned modifications:
Custom LED turn signals. Windshield. Highway Pegs. (Possible) ignition adv. Tuxedo Mod. Ignition coil mod.

Last edited by Jason Pittenger; 05-28-2018 at 02:00 AM.
Jason Pittenger 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