1980 900 SS Bosch Ignition Wire Replacement

Post your 'Electrical & Gauges' FAQs, comments & questions regarding Ducati motorcycles here.
Post Reply
jsey
Mariana
Posts: 37
Joined: Thu Nov 23, 2006 4:54 am

1980 900 SS Bosch Ignition Wire Replacement

Post by jsey »

Steve,
If your watching, Got the cover off and its hard to believe that the engine ran at all. The ignition wires were essentially bare with no insulation. This is the question. It doesn't look like you can replace the wires back to the beginning within the pick up. So I assuming the wires must be cut and spliced then heat shrunk. Doesn't leaving that small amount of original wire represent a future potential flaw. The first two inches, however, look to be in good condition. I assume it was the oil that preserved them. Are new pick ups with new wires not available? Thanks

Jonathan

wdietz186
Cagiva Alazzura
Posts: 703
Joined: Sun Sep 10, 2006 5:40 pm

Post by wdietz186 »

Jon, The wire is not the problem but the insulation is. The repair is to cut and splice close to the pickup using shrink tubing to insulate the original wiring. I would cut about 1/2 to 3/4 inch from the pickup and go from there. Be very careful and note which wire goes where. The polarity makes a difference. Use plenty of contact cleaner to make sure the wires are free of oil before you solder them. DO NOT move the pickups as this will change the timing and it requires a special tool to reset. Steve has obtained some wire suitable for this job and looks to be the way to go.

jsey
Mariana
Posts: 37
Joined: Thu Nov 23, 2006 4:54 am

Post by jsey »

Thanks Dietz. I got some of that wire during the week and am ready to go. Thanks for the info

User avatar
BevHevSteve
SITE OWNER
SITE OWNER
Posts: 2210
Joined: Wed Mar 10, 2004 8:53 pm
Location: Lafayette, California
Contact:

Post by BevHevSteve »

yep just use the high quality 3M heat shrink tubing, the kind that has the sealant stuff on the inside, cut the wires about a half inch away from the pickups and replace wiht the new wire. Use the heat shrink all the way back up to the pickup. After everything is cleaned, and you do the job, use some ThreeBond to seal around where the wires exit the pickups and you are good to go. Polarity does make a difference, make sure you take good notes as to which wire goes where.
Image
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
Ducati/Euro Spares -> https://Store.BevelHeaven.com
Facebook > http://facebook.com/Bevel.Heaven
Twitter > http://www.Twitter.com/BevelHeaven

KevinVernon
Cucciolo - the Lil Pup
Posts: 9
Joined: Mon Aug 03, 2009 3:46 pm

type of 3M shrink tube to use for ignition wire splice

Post by KevinVernon »

I've been browsing 3M datasheets looking for heat shrink that sounds like the stuff suggested in this thread.

So far the best bet looks to be 3M ETW-803 in the 3mm/1mm size. Does this sound right?

User avatar
Osred
Diana
Posts: 67
Joined: Mon Apr 23, 2007 1:33 pm
Location: Seattle, Washington

Polarity Check - Proper Wire Connection

Post by Osred »

The four pickup wires were already cut when I received a spare motor. How does one know which wires go with eachother if they are not individually color coded? How is polarity confirmed?
"Red hair and black leather, my favorite color scheme."

KevinVernon
Cucciolo - the Lil Pup
Posts: 9
Joined: Mon Aug 03, 2009 3:46 pm

Post by KevinVernon »

Wires were originally colour codes in pairs, each pair containing one white and one white/black coded wire. Since yours have been cut you will have to open the case to determine how the wires pair up even if you have insulation left.

The brown and white wires run to the central pin on the 'square' end of the bosch connector, actually labelled brown/white on my old connectors. The white wire of each pair runs to the other pin on the squre end of the connector that has a contact in it.

When you look within the case the lower pickup is for the front (horizontal) cylinder, the upper pickup is for the rear (vertical) cylinder.

Assuming all engines are wired the same for pickup poplarity then the lower wire on each pickup is the white/black wire.

Good luck with your rewiring. I take it you are planning to rewire all the way down to the pickups. My insulation was completely shot and fragmented all the way from pickup to the control unit which I wouldn't have discovered had I not caught the wire when pilling the engine out to get the frame powder coated.

Post Reply

Return to “Electrical & Gauges Shop”