Improving the Honda 160 Roadracer:
Installing a Pertronix Ignitor

 

I've been meaning to write an article on mounting the Pertronix Ignitor on a 160 roadracer for some time now, but just haven't had the time.   I'll get a start here, and it'll have to do for now.   These instructions assume you're using Pertronix part number 1847a (or similar), which is the model number used for a Bosch 009 distributor - common on Volkswagens.   I bought mine from a Bow Wow Autoparts store north of Seattle.   Just about any VW shop ought to have them in stock.   They're also available on the net.

There are other points replacement hall effect sensors out there - Dan Hill is using a different brand that according to the VW shop he bought it at is better than the Pertronix.   The mounting will be similar regardless of which brand you use - it'll likely be fairly obvious what you need to do.

Here is how the ignitor comes from Pertronix.   The red wire will be going to the positive side of the coil, and the black wire to the negative side.   You'll be taking the ignitor off it's backing plate here and mounting it to a stock Honda points plate.

Pertronix Ignitor as it comes from Pertronix.   Photo Copyright © 2002 Michael Bateman
Pertronix Ignitor, as it comes out of the box.

Pertronix Ignitor and Honda backing plate.   Photo Copyright © 2002 Michael Bateman
Pertronix Ignitor, removed from it's backing plate with a Honda points plate.

You can see here that the Honda backing plate has had the felt wiper and it's bracket removed from the points plate as it's in the way of mounting the ignitor, and not necessary anymore.   I used one of the tapped holes that was for mounting the points to mount one end of the ignitor.   The other end is mounted after everything is together so that the spacing between the magnet sleeve and the ignitor module can be set.

The next thing I did was to machine an adaptor to mount the magnet sleeve that comes with the ignitor set to the nose of the cam in place of the stock points cam and advanced unit.   Here's a photo of it:

Pertronix magnet sleeve and aluminum cam nose adaptor.   Photo Copyright © 2002 Michael Bateman
Pertronix magnet sleeve and adaptor

The adaptor is machined to approximate the Bosch points cam so the magnet sleeve fits over it snugly.   The other end is turned down to fit inside the Honda points plate, and bored to fit the nose of the cam.   for 160 cams that's approximately 10mm, and for 175 cams that'd be approximately 11mm.   It also needs a slot machined in the base to match the index pin on the cam nose.  

I'm now offering these adaptors as a finished product.   For now you'll have to contact me directly, but I'll eventually have them and quite a few other products listed on the BatemanRacing website.   If you want to use another unit I'd be happy to make an adaptor for you. Shoot me a note and we'll discuss it.  

You'll need to take the bottom retainer off the magnet sleeve and remove two magnets so there's two remaining, 180 degrees apart.   The pole of the magnet matters, so if you're not careful enough and you drop them all like I did you'll have to figure out which way 'round they're supposed to go.   I hooked everything up and passed the magnet in front of the ignitor.   One way it'll make a spark, the other way it won't.   Put it in the sleeve the way that makes a spark...

Pertronix Ignitor mounted on the bike.   Photo Copyright © 2002 Michael Bateman

And this is what the ignitor setup will look like mounted on the bike.   Pertronix specifies 0.030" to 0.040" between the ignitor unit and the magnet sleeve, with the bottom of the sleeve lined up with the bottom of the ignitor.   That will center the magnet on the hall effect sensor.

It took a litle messing around to figure out how to set the timing, but once it was set it hasn't moved at all.  

And here's two photos of the Accel coil mounted on my 160.   The left side shows the two wires coming from the ignitor and the coil mounted in the stock position on the frame.   The right side shot shows how the posts on the Accel coil fit through the frame.   What doesn't show every well is that you need to remove just a little bit of metal from the front and rear side of the bracket for the spark plug lead boots to fit on the coil posts and clear the frame bracket.   A few minutes with a half-round file will do it, and it'll be obvious what's needed.  This is a 3.5 ohm coil made to work with points.  

Pertronix Ignitor mounted on the bike.   Photo Copyright © 2002 Michael Bateman
Accel coil on 160 - left side

Pertronix Ignitor mounted on the bike.   Photo Copyright © 2002 Michael Bateman
Accel coil on 160 - right side

The Pertronix ignitor will work just fine with a stock coil, or any coil made to work with points.   I'm using the Accel as I found a good deal on Ebay.   This one was going to be used on a Harley project, but the fellow decided on a different coil in the end.

Enjoy not having to mess with timing again!

Cheers - Michael


 

Copyright © 2002-2008 Michael Bateman
Photographs Copyright © 2002-2008 Michael Bateman

Email: michael at groupwracing dot com