Wiring harness trouble

I'm replacing the wiring harness on my 87 700 with a wiring harness from an 86 700. The new harness has four separate conncections for the spark unit while the spark unit only has 2 possible places for connections. The connections on the harness are 4 wire, 6 wire, 2 wire and a single wire. The connections on the spark unit are for the 4 and 6 wire.

Is it possible to just eliminate the 2 and 1 wire connection?

I've looked at a 2nd gen wiring diagram and it shows the spark unit as using all four connections, however my spark unit only has 2 inputs.

Does anybody know if the 87 wiring harness and spark unit differ from the 86?

 

Sure they differ due to the extra cam pulse generator connection. You probably ( i'm not certain) need the cdi from an '87 to make things work or maybe you can figger out how to connect the cam pulser to the box as a jumper wire setup since there is no connection through the new wiring harness.

 

Do you mean I'll need a cdi from an 86? And how would you run a jumper wire setup?

 

One of the many upgrades to the 87 was fully digital cdi (no cam sensors) so I'm pretty sure the cdi is different and the harness would be different allso. I was carefull when I bought spares to be sure they were off a 87, some people on Ebay list 86/87 as the same.

Here's info on 87 updates.

In 1987, the VFR700F2 was the only model sold in the US. The blue/silver model was introduced featuring black engine covers, a midnight blue finish and silver wheels, seat and decals. Functionally, the ’87 included many improvements. The ignition became fully digital and no longer required the Cam Pulse Generator. The tachometer no longer fed into the spark unit. The gear shift-arm was shortened for more positive shifting. The front forks were given more damping (though this still left much to be desired). The rear suspension linkage was improved. A new Pro Link shock was intrroduced. Many engine components were strengthened and lightened. The valve rocker arms were redesigned to cause less friction.

 

Your engine doesn't have the cam sensor needed to run the 86 ignition box. I don't know if this will keep it from running, but it might... Your tach most likely won't work, if the bike runs at all. I assume you need an 86 ignition box too.

Sell the 86 harness and get an 87.

Good luck with your fix...

kevin

 

Sorry, i'm an amateur idiot and gave improper advice.

 

Sorry, my earlier advice was seriously in error.

Please visit my website: www.imightbeanidiot.com

 

You need to back up and get the correct harness.

 

Thanks captb. That was very informative. Looks like I'll be looking for an 87 wiring harness. Just wondering how you found out the differences between the bikes? Like a certain website or is it from a variety of sources?

 

When I was looking for a VFR to restore I found info all over the web and since I was going to repaint what ever I bought it was only logical to buy the 87 with more refinements.

 

Hey, here's an 87 harness on eBay for $40! That's a buy-it-now with free shipping.