Total Motorcycle Community Forums

We are a group of 5 students at the Georgia Institute of Technology who are converting a 1976 Honda CB 750 to EFI using MegaSquirt. We are conducting a market research study to gage the interest of a MegaSquirt conversion kit for older carbureted bikes. Here is a link to a 3 question survey, Thanks in advance. We will keep you all posted with the results of the survey.


http://www.surveymonkey.com/s.aspx?sm=k ... mQBA_3d_3d


--
Megabike Team

Good idea if you make a REAL fuel injection and not an EFI (like an early Vette or Bosch type you know NO COMPUTER) This was actually done before by a company called Lake Injectors

LUCAS dosen't like electronics!

I'd only do it if I were unable to get carbs or carb parts for the old bike.

I've assisted on a few megasquirt installations on old KZ bikes. It's a real pain to get it just right and there's no discernable performance improvement over the stock carbs.

slimcolo wrote:Good idea if you make a REAL fuel injection and not an EFI (like an early Vette or Bosch type you know NO COMPUTER) This was actually done before by a company called Lake Injectors

LUCAS dosen't like electronics!

I am thoroughly confused. What kind of electronic fuel injection doesn't use a computer?

There have been several fuel injection systems that were not Electronic. The first electronic injection systems (Nash/AMC 1958) did not have a computer.

Interesting that the first application of fuel injection was for a motorcycle in 1896 by E.J. Pennington.

http://en.wikipedia.org/wiki/Fuel_injection

slimcolo wrote:There have been several fuel injection systems that were not Electronic. The first electronic injection systems (Nash/AMC 1958) did not have a computer.

Interesting that the first application of fuel injection was for a motorcycle in 1896 by E.J. Pennington.

http://en.wikipedia.org/wiki/Fuel_injection

How were the injectors controlled if there was no computer? A hard-coded set of microchips?

I also found this information about the "first electronic injection system," called "Electrojector."

"Electrojector" Fuel Injection System

The optional Bendix system is monitored by an electronic control box, located on the right side panel under the instrument panel, to gather the following data; full throttle enrichment, acceleration enrichment, idling requirements, fuel enrichment for quick starts and warmups, and deceleration fuel cutoff. The control box gathers this information and correlates it for timing the fuel charge by electrically actuating the injectors. The injectors spray fuel directly into each intake port in calibrated quantities at timed intervals.

The "electronic control box" sounds a lot like a computer to me.

Skier wrote

How were the injectors controlled if there was no computer?

At least two different ways.
Mechanical using valves as injectors.(usually vacume operated) Fuel rate was adjusted manually much like an adjustable main jet on carb.

Electrical using the point's electrical power to open injectors as well as firing the plugs. (they would fire #1 plug and #3 injector with firing order 1-3-2-4, points gap and timing had to be almost perfect) Fuel rate was controlled by changing injectors much like changing carb jets

Both types used a varity of pressure control (fuel pump/pressure regulator, compressed air control, pressurized fuel tank like Moon and yes some used plain ol gravity) Electronic would be to bulky, heavy and fragile. (this was the era of tubes before micro chips or transistors) Most of the earlier systems were not as good as a carb except in diesel engines and in aircraft.

Couldn't find info on the old Lake Injector (they were not really an injector but not a carb either sorta of a 1/2 breed)

I'm well aware of mechanical fuel injection. I was wondering how electronic fuel injection works if there is no computer to control how much fuel to inject with the electronically activated injectors and the latest post shows one way: using the points-type ignition to open the injectors.

Back to the topic at hand, MegaSquirt is a computer controlled unit with almost unlimited flexibility.

What's up with this conversion how's it going