Considering EFI; What type of ignition system on 82 xs400rj?

[OnePhate]

I keep looking at EFI the more I look at the carbs, I'm considering learning how to convert bikes to EFI for two reasons: I hate carburetors, and it might make me some good money as I have quite a few friends interested in converting to EFI but not interested in experimenting.

 

[Travis]

If you're not interested in experimenting, I wouldn't even try. This won't be all that easy to do. You'll need a custom intake manifold with fuel injectors, fuel pump, a throttle body, and according to Yamaha_Chop on XS650.com, for sensors you at least need a throttle position sensor, engine temp sensor (have to use oil since we don't have coolant), air temp sensor, coil reference signal, and MAP sensor. It's quite the project. Carburetors are real easy compared with trying to convert to fuel injection.

As far as I know, the ignition is a TCI on your 82 RJ.

 

[OnePhate]

I said my friends aren't interested in experimenting. I am. Thanks for the reply. I'll go try to find that thread.

 

[lhaolpa]

The easiest way would be with throttle body ignition as you could use a gutted out carb for the body,then mount all the other stuff on to it,Get the sensors off a Toyota or something like that.My Nissan Hardbody truck has TBI,and runs fairly well despite 170,000 miles.You would have to use one carb at any rate,as I've never seen a FI with more than one intake.Other than that,I don't know much more. lha

 

[Travis]

OnePhate, Sorry I misread your post. This is the thread I was talking about http://www.xs650.com/forum/showthread.php?t=75

Here is Sky's (Yamaha_Chop) build thread: http://www.xs650.com/forum/showthread.php?t=229

 

[OnePhate]

Thanks guys, I was planning using the carbs, minus the slide as throttle bodies as I have seen on the microsquirt website, and planned to mount the injectors in the air box, pointed at the carbs. I just have to decide which of my bikes I'm keeping first, the ugly rusted out one with <5k miles or the rebuilt one with >12k miles. Both '82 Seca's.

 

[OnePhate]

Should I mount the injectors before or after the throttle bodies?

 

[lhaolpa]

In the bore for the slides would be where I would try to put the injectors.It would work better in a single carb,but would work with two,but finding injectors with the right flow would be the problem. lha

 

[Zach_J]

If it were me, I would try to score the ITB's off of a Liter bike. Just use 2 of them and already you have the injectors, Throttle position sensor, and most likeley they would be sized pretty closely to the induction requirements of our engines. You might even be able to retrofit the fuel pump from one to get the fuel pressure you need.

 

[Travis]

^ I was kind of thinking the same thing. If they were too big you could look at the 750s and 600s too.

 

[user11206]

I have been toying around with the idea of a mechanic fuel injection system for my bike as well, thinking of ways that I could do it. Here is what my basic idea was, I'm sure that it could be adapted for an electrical though.


Components:

1. Throttle body
2. Two Fuel Nozzles with manifold
3. Fuel Metering Unit
4. Vacuum Driven Leaning Valve
5. Boost pump
6. Momentary switch
7. Oil Pressure switch

You have one throttle body which is just a machined block of aluminum with a throttle plate inside. So it has throttle linkage on one side, this is driven by your twist grip on the bike. On the other side of the throttle body you have a fuel metering valve which is a rotary valve. As you increase throttle position, the fuel metering valve is rotated allowing more fuel to be sent to the fuel nozzles. Now depending on throttle position the manifold pressure increases in the intake, a small line is tapped off the intake to a vacuum valve that will partially open and close to control the mixture depending on the amount of air is flowing through the intake.

It is temperature compensating because when Outside Air Temp is cold, the density is high, therefore more vacuum will be pulled on the valve which will lean the mixture out. The diaphragm also gets impact air on one side, and vacuum on the other. Depending on impact air will determine the action of the vacuum diaphragm. This way if there is less air rushing into the intake, the vacuum will pull more and fuel will flow to the nozzles. As impact air increases, we can lean the mixture out and impact air will close the diaphragm more to lean the mixture.

For starting, you press a small button which turns on a small boost pump and will shoot some prime right into the engine. Once running a oil pressure switch begins to run the pump. This acts as a engine safety switch - if engine runs out of oil, engine shuts down.

Sounds crazy but it is modeled after an aircraft so I don't see why it wouldn't work, I have changed it to work more for a motorcycle, including the boost pump and oil px switch. Thought I would share with you.

 

[16VGTIDave]

Couple thoughts:

- mechanical injection isn't much better than carbs, so lots of effort for little gain.
- priming switch could be replaced by starter connection. Hit starter, priming occurs.
- 1 throttle body isn't a good idea with 180 crank. #2 will be fighting a loosing battle with #1
- aircraft engines aren't much more than stationary engines. Motorcycles and cars have greatly carrying loads and are much more demanding on fuel systems.

Stick with the CV carbs until you are ready for EFI. Then look at microsquirt.

 

[user11206]

Yeah you're right, aircraft just a cruise rpm and keep it there, so fuel system doesn't have to be on the fly like a road vehicles fuel system, constantly on and off the throttle. LoL I always like to think outside the box.

I was looking online and it seems there are a few EFI options out there already.

 

[Rumpelhardt]

Electronic fuel injection would be a better way to go I would think. Are there any motorcycles that use direct port injection? If there are you might be able to adapt injectors from one. The problem would be controlling it. You'd have to adapt a computer and be able to program it and you'd also need a reliable source of electric power.

 

[16VGTIDave]

For conversions like this, megasquirt or microsquirt are the way to go. 100% programmable fuel and ignition. And the price is reasonable as well.

 

[Travis]

This thread is over 4 years old. Is this something that would be easier to do now than it was 4 or 5 years ago? Basically what I'm asking is are the megasquirt or microsquirt systems easier to put together and are parts like sensors and things easier to come by? Is programming easier? Are the components smaller? I know very little about these systems as you can probably tell.

 

[16VGTIDave]

Technology marches on! Yes, converting to EFI is getting easier, and less expensive, every year. Take a look at the quick start guide for microsquirt.