About Us

The blog for newbies wanting to build a legitimate custom motorcycle
Showing posts with label Electrical. Show all posts
Showing posts with label Electrical. Show all posts

Monday, February 1, 2010

Points vs Electronic Ignition

Before the mid 80s motorcycles used points type ignition systems.  The purpose of the points was to complete the elecrical circuit at precisely the right moment to fire the spark plug and ignite the compressed fuel in the cylinder.  There was some time of mechnical link that connected the points to the cam shaft so that the contact would complete the circuit when all the valves were closed and engine was at top dead center.  More on How Points Work

XS650 Points Assembly (http://www.650motorcycles.com/XSpoints.jpg)

The system worked well and was fairly simple.  However, the contact often were fail, become corroded or need to be adjusted.  If you talk to anyone who rode bikes alot before the 80s they'll often talk about carrying a extra set of points during log rides because it was so common to have the system fail.

For my project I did not want to mess with all the work it takes to adjust and maintain a points ignition system.  Luckily, a new electronic system is now available that works wonderfully.


the Pamco Ignition System is a drop in replacement for the old points on a Yamaha XS650.  This system replaces the original points with a small hall effect sensor.  This, coupled with a high output coil make for a very robust and almost foolproof system.

The Pamco System



I completed the conversion on my bike in one relaxed evening in the garage.  The instructions that come with the kit are easy to follow and customer service is excellent if you run into any trouble.

One word of warning, you can wreck a coil and the sensor if you do not have the proper fuse installed.  I skipped this step and it cost me dearly.

Wiring Diagrams

Wiring is often the bane of a motorcycle project.  A rats nest of multicolored threads pouring out of small box tucked under the seat.  Here's a few links for diagrams to make it a bit easier.

Stock Wiring 1970 - 1982

Chopper Wiring

Especially when working with older bikes don't go cheap, get a new wiring harness.  It's worth the money in time you'll save not having mess around corroded terminals and cracked shorted wires.