ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-30-2012, 03:19 AM   #1
a_bakla OP
A&F
 
a_bakla's Avatar
 
Joined: Oct 2009
Location: Turkey,Tekirdağ
Oddometer: 116
airhead Ignition Control Unit ( ICU)

My G/S runs with an ICU different than the stock one.I think bike previous owner changed it. I ve searched that what is it? İt is russian car Lada's igniton control unit????.I've found specs of this unit. (3620.3734)

Range of operating temperatures, С
-40 .. +85




Nominal supply voltage, V
12,0






Permissible limits of supply voltage, V
6,0 .. 18,0






Range of an uninterrupted spark formation, rpm of the crankshaft of the 4-cycle 4-cylinder engine
20 .. 7000






Commutating current, А
7,5 0,2






Time of a sparkless cutoff of a collector current, sec
1 .. 2






Maximum allowable influence of the increased supply voltage up to 5 min. at the spark formation frequence more than 200 Hz (6000 rpm of the crankshaft of the 4-cycle 4-cylinder engine), V
25,0






Maximum allowable pulse overvoltages of a positive and negative polarity, V
150,0








And schematics is there : http://www.vtnauto.com/en/3620.html#techdata

I wonder is this unit suitable for an airhead ?
I am planing to convert my g/s to twin spark.I ve already drilled the heads and and searching for second ICU and coil.
This unit is very easy to get and cheap (10$). Can I use this unit or is it better to get stock black ones?
a_bakla is offline   Reply With Quote
Old 10-30-2012, 05:20 AM   #2
Rob Farmer
Beastly Adventurer
 
Rob Farmer's Avatar
 
Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 5,258
With the exception of the kickstart icu the ignition modules are the same as dozens of European cars from the 80s and 90s including Porsche. The most common variant is a Lucas dab400

Rob Farmer screwed with this post 10-30-2012 at 05:27 AM
Rob Farmer is offline   Reply With Quote
Old 10-30-2012, 05:55 AM   #3
boxerboy81
Stay Horizontal
 
boxerboy81's Avatar
 
Joined: Jul 2009
Location: Melbourne, Oz
Oddometer: 2,246
Not sure they're quite the same over the years. There were a few updates finishing with the turquoise lettered one being the last and covered all predecessors. Other versions may work, but they may not be the same despite appearances.

The turquoise lettered ICU
pn 12-14-2-325-284 with riveted heat sink instead of small bolts is the last one made by BMW. The heat sink is integral and doesn't require periodic servicing of heat sink paste. It has the latest updates and works for bikes with a kicker or not.
boxerboy81 is offline   Reply With Quote
Old 10-30-2012, 08:50 AM   #4
chasbmw
Beastly Adventurer
 
Joined: Feb 2006
Location: Bath Uk
Oddometer: 1,892
You need a second coil, but I don't think that you need a second ICU.
__________________
Charles
http://i46.photobucket.com/albums/f1...ps6e61ae2e.jpg
R90s 1070 replica, R90/6
1971 Commando Fastback
chasbmw is offline   Reply With Quote
Old 10-30-2012, 01:14 PM   #5
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,452
ICU's are not all the same. The torquoise ICU's from BMW can take lower coil primary resistance. Tha'ts the main spec to deal with regarding ICU's which I can't ascertain from those specs. The rev limit is too low as well if it matters? Run the same primary resistance as what the ICU was originally run with or a little higher but never lower. That will fry the ICU. Too high Primary resistance can weaken high rpm spark from what I have read although I haven't found this out for myself. I HAVE found out about matching ICU's to too low primary resistance myself!

I am running two .7 ohm dyna's on my dual plugged stock bean can with the weight stops bent in to restrict full advance. It is running good!
supershaft is offline   Reply With Quote
Old 10-30-2012, 09:46 PM   #6
motu
Loose Pre Unit
 
motu's Avatar
 
Joined: Dec 2001
Location: New Zealand
Oddometer: 4,387
The Lada Samara uses the BIM 137, it's used in a lot of after market ignition systems because it adjusts dwell. It's the same case as the airhead module - you'd need to see a diagram of the pins to know if it relates to the one on airheads. Worth a try on someone else's bike.
motu is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not 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 On

Forum Jump


Times are GMT -7.   It's 03:37 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014