Article of the Week – Fuel Injection ConversionPosted: May 4, 2011
by Todd Quigley
This week I’m combining a bit of my “Friday’s Fun Find!” into my article of the week. Recently I came across something of interest to me as an old motorcycle owner; MicroSquirt Fuel Injection. What is MicroSquirt you ask? How is it interesting to owners of old motorcycles?
I’m glad you asked! MicroSquirt is a wonderful gadget from Bowling & Grippo that enables you to install fuel injection on almost any carbureted motorcycle! Not only does it allow for fuel injection, it can also handle ignition duties as well. Just think of it; my 1983 Honda CX650 Custom decked out with state-of-the-art fuel injection and electronic ignition!
Now, MicroSquirt is not for the faint of heart. You will need to educate yourself fully on fuel injection and how it works, especially as it relates to motorcycles. Luckily there exist books that can do just that. Also, MicroSquirt has it’s own forum for people to post what they’ve done or to ask questions. Almost every application will be unique as well; motorcycles range from 1 cylinder to 6 cylinder and vary from cam-fired breaker point ignition to crank-fired electronic ignition.
At this point in my life, I am not ready to absorb the cost of this installation, but I do plan on it as soon as I can afford it! The system itself runs about $400, however that does not include the price of fuel injectors, throttle bodies, fuel pump, sensors, and other odds & ends needed to install it. From what I could gleen off the forums, I would expect to shell out about $800-$1,000 for the total conversion. What does that money buy for me? Piece of mind. I don’t really need it right now. The twin carbureturs, though fitful, still work. The existing 1983 electronic ignition also still works. Before too long things will fail. Carburetor parts for my bike are very expensive as are the eletronic ignition components. Soon they will be impossible to get. Though some components were shared across different models, many of the parts for my bike where specific to just that particular model. Only about 1,800 were made. I’m sure an infinite supply of parts wasn’t made either. In fact I am certain of it as several components to my bike are not available new any longer.
The MicroSquirt would help alleviate some of those issues. I could utilize throttle bodies off a twin cylinder motorcyle of 600 to 800ccs that is much newer. The electronics needed for the electonic ignition could also be bought new off the shelf. Using these newer components could buy me years or even decades of reliable operation.
Here is what I would need to install it on my motorcycle:
- MicroSquirt Module and wiring.
- GM MAP Sensor to read vacuum in the intake.
- GM Temp Sensor to read engine temperature.
- Some sort of Hall Effect or Variable Reluctor pick-up to read the crank ignition signal.
- Preferably a Wide Band Oxygen Sensor to allow MicroSquirt to adjust the air/fuel mixture.
- 2 Throttle bodies and fuel injectors from a similarly sized motorcycle.
- A throttle position sensor (hopefully included with the throttle bodies).
- A Fuel Pump from a fuel injected motorcycle.
Assuming I do it correctly, I would ensure all these new items were easily replaceable allowing continued repaiability of the motorcycle by myself. I would also need to make detailed notes about what year, make, and model of vehicle each component came from so I can easily order replacement parts in the future.
Even though I’ve listed the components I need, the actual work will be very hard. I will need to adapt each component to a vehicle it was never designed to work on. I’ll also need to fully customize the software on the MicroSquirt to work properly with my engine design. This project will require a lot of research and effort to complete. I look forward to tackling it sometime down the road!