Fuel injection on a Boom Vader 125

[Lucas@Air_Lift]

I have disabled ego correction by setting its controller authority to 0, as disabling it stops the ecu from datalogging the sensor. I also disabled auto idle and smoothed out the fuel map. She runs damn good now! Still more datalogging needed, but making good progress on the tune. I have decided against flashing BG software to it for now. Here is my current tune for your viewing pleasure

Edit: I also think I figured out my fuel pump issue. It is two things:
1. The inlet port on the pump is facing downwards, which I think is trapping air bubbles causing the pump to cavitate.

2.My fuel filer is below the pump, which I am sure is also trapping air bubbles.

I am going to reroute the fuel lines and possibly redo the return line as I suspect it could also be causing issues.

[Lucas@Air_Lift]

I think this solved my fuel pump issues! Mounted the pump lower and shortened the feed line.


Changed the return line back to how it originally was


And drilled a small 1/16" hole for a vent. This is temporary, not sure what I will end up doing for a vent


So far so good! Runs so much smoother, but I think it's too rich on the top end now

[Megadan]

Thanks for the update. Hopefully the EGO correction is just an odd fluke, but if all else fails I have a wideband and gauge I can use to tune with. Hope is restored lol. Glad you can enjoy your bike. It's so frustrating when you can't ride.

[Lucas@Air_Lift]

So I think I am still having fuel pump issues. Without a fuel pressure gauge mounted to my brs its hard to tell. But, I finally got around to putting my new muffler on!

Not the prettiest but these mig welds will hold up




Anyone have a lower rear fender they arent using and want to sell? The stock muffler destroyed mine.. but muffer looks good on there!

[Lucas@Air_Lift]

It most definitely has a fuel pressure issue. I am either not going to ride it, or put a carb back on until I have enough money to get an ecotrons fuel pump and regulator. I about got killed on my ride home because it wanted to suddenly not make power.

[Lucas@Air_Lift]

I think I may have figured this out. The small ~20ga power wires feed the entire EFI system.. CDI box, fuel pump, injector, all of it, I think isn't flowing enough current. I have noticed that while the bike is running, the fuel pump sounds like it is spinning significantly slower than when the bike is off and I am priming the system. A Multimeter confirms that the pump is only getting around 10V with the engine at idle, so I can only imagine that is even less as the revs go up and the CDI starts sucking down more power. I am going to try using the connector off the EFI harness to trigger a relay, and run the relay power and pump ground direct to the battery.

I am really at wits end with this project. It's very hard for me to justify spending another $100 on a new pump and regulator when I can buy a nice carb for that price. If this doesn't work, I may just give up on this

[JerryHawk250]

Originally Posted by Lucas@Air_Lift

I think I may have figured this out. The small ~20ga power wires feed the entire EFI system.. CDI box, fuel pump, injector, all of it, I think isn't flowing enough current. I have noticed that while the bike is running, the fuel pump sounds like it is spinning significantly slower than when the bike is off and I am priming the system. A Multimeter confirms that the pump is only getting around 10V with the engine at idle, so I can only imagine that is even less as the revs go up and the CDI starts sucking down more power. I am going to try using the connector off the EFI harness to trigger a relay, and run the relay power and pump ground direct to the battery.

I am really at wits end with this project. It's very hard for me to justify spending another $100 on a new pump and regulator when I can buy a nice carb for that price. If this doesn't work, I may just give up on this

That might solve the problem. It's not a large pump but to get 45 psi i'm sure it draws some amps. Every fuel pump I have installed was on a relay. Don't give up.

[Azhule]

I agree, you should at minimum add a Relay to that system with how demanding it is...

What type of connectors does the wiring come with? You might be able to buy new marine grade wires, correct size crimp connectors, and solder everything up nice (along with a relay) for under $20

[Megadan]

Don't give up. The relay idea is a good one as most fuel pump output is directly related to the power it sees. That is why some people "hot rod" factory fuel pumps with direct power to bump the voltage/current up. If you look at any flow chart of a walbro, they have different stated flow rates at 12V and 14V for this very reason.

If all else fails and you decide to go carb again, I can easily be convinced to take that EFI setup off your hands if you want to sell it.

[ras2627]

we going to get an update youtube video soon would love to hear it on the road... plus thx for documenting this journey thinking of doing it to my Chinese dual sport when i get second bike

[Hell2go]

Originally Posted by Lucas@Air_Lift

I think I may have figured this out. The small ~20ga power wires feed the entire EFI system.. CDI box, fuel pump, injector, all of it, I think isn't flowing enough current. I have noticed that while the bike is running, the fuel pump sounds like it is spinning significantly slower than when the bike is off and I am priming the system. A Multimeter confirms that the pump is only getting around 10V with the engine at idle, so I can only imagine that is even less as the revs go up and the CDI starts sucking down more power. I am going to try using the connector off the EFI harness to trigger a relay, and run the relay power and pump ground direct to the battery.

I am really at wits end with this project. It's very hard for me to justify spending another $100 on a new pump and regulator when I can buy a nice carb for that price. If this doesn't work, I may just give up on this

It sounds like your stator doesn't produce enough power at idle, try checking the voltage while revving the motor a little. IF the voltage comes up then it would only be affecting EFI at idle... if it doesn't come up, either the voltage regulator is bad or the stator is weak. IF it's the stator, replace it with an aftermarket performance one... just don't give up yet, we are all counting on you!

[Rangerscott]

Id try to fit a bigger more powerful battery too.

[prismways]

A bigger battery would be nice, but it's already super tight in the cavity as is.

Originally Posted by Rangerscott

Id try to fit a bigger more powerful battery too.

[Lucas@Air_Lift]

Well guys... I hate to say it but I have pulled the fuel injection off the bike I rewired the fuel pump which did make a big difference, but it still had serious drivability issues that did not make me feel safe riding it. I have beem super busy working on the drift car, drifting events and getting the yaris ready for time attack so this has been on the back burner. But yeah, spent some time on it the last few days and I finally gave up. Sorry to disappoint everyone. I 100% know that I could get it running perfect if I could run genuine B&G megasquirt hardware.

For now at least, the Boom will be running a cable choke PZ26 from MaxAuto, and so far it runs fantastic. Using the out of the box jets (35 pilot, 95 main) amd about 1.75 turns out on the bleed resulted in great running conditions... but it may be a little too rich. Anyway once again sorry to disappoint you guys, but I can only throw so much money at it before I had to throw in the towel.



PS: Im not selling the kit just yet. I am going to save up for a microsquirt over the winter and try to inject it once again next year.

[JerryHawk250]

Sorry to here it's not working out. Maybe when you come back to it and have the time to really focus on just the that it will work out. At least it's up and running for the time being.