Motorcycle – Page 24 – Not Your Average Engineer

February 24, 2015July 9, 2020

Cat Rack, Rest, and Light

There is a new option for Honda Pacific Coast PC800 rear racks, backrests, and high tail lights. Richard Shavor (Facebook, Ebay) has started producing the Cat system of rear racks, passenger backrests, and high tail lights for the PC800. I have not personally tried one of his rear racks but the look like a good design and are definitely a good option for people wanting a rack for a PC. The backrest and third brake light also look quite good. To purchase this rack, contact Richard directly via Facebook or Ebay. Below are a few photos from Richard’s Ebay auctions for the racks.

Good-looking rack that appears to be made out of sheet metal and either painted or powder coated black. Note the weight-reducing holes on the sides and the slits in the top.

The Cat Light bolts onto the Cat Rack and has wiring to connect into the brake or running light circuitry of the bike.

The Cat Rest backrest attaches to the Cat Rack with four bolts and does not directly attach to the rest of the seat assembly.

The whole kit is available together as well.

December 9, 2014February 24, 2015

Building a Vacuum Reservoir for a Honda Pacific Coast Fuel Injection Conversion Project

This humble pipe will be the vacuum reservoir on my Honda Pacific Coast PC800 fuel injection conversion project. I have been working for some time on converting this carburetted bike to fuel injection. One issue has been a fluttering manifold air pressure reading from the Manifold Air Pressure (MAP) sensor when it is hooked directly to the intake runners. The solution is to have a vacuum chamber to smooth out the pulses from the opening and closing of the engine valves. The pressure readings will still be correct but without the huge flutter problems.

I JB Welded in brass fittings to the two screw ends of the PCV pipes. Once everything is dry, I will bolt it all onto the bike under the plastic.

December 7, 2014February 24, 2015

Adding Vacuum Taps to a PC800 Throttle Body

I did some work today to add a second set of vacuum taps to the Honda Pacific Coast PC800 carburetor that I have modified into fuel injection throttle bodies as part of my long-running fuel injection conversion project. In this photo you can see two metal pipes penetrating the lower portions of the throttle bodies. These pipe taps will act as vacuum taps. I am going to hook either the Manifold Air Pressure (MAP) sensor or an Idle Air Control (IAC) valve to these taps. The other existing factory-installed taps will be used for the MAP or IAC that isn’t plugged into the new set of taps.

Here’s the finished view with vacuum hose hooked to the new taps and the new tapx shaved flush in the throttle bodies.

My finger is pointing to the new tap.

All in all, it was a pretty clean installation. I used JB Weld to hold everything together. Hopefully the 10% ethanol gas that we get everywhere in the USA won’t someday degrade all of the JB Weld that holds together the throttle bodies.

The throttle bodies installed on the bike. Lots of hoses and wires running everywhere to make this bike come alive! Up next is figuring out how to make the MAP sensor not flutter all over the place (vacuum reservoir) and finally figuring out how to do proper idle air control using an IAC that works with my existing MicroSquirt setup. The engine really needs IAC so that it will properly start when the engine is cold.