[Cybeeria]

I recently picked up 2005 F4 750 SPR. The bike ran when I looked at it a few weeks before the auction and when I got it home a few days ago the battery was too flat to turn the bike over. I charged it up fully (it's a new high quality battery) and the bike goes thru the gauge initialization sequence just fine and cranks with gusto but won't start. After doing quite a bit of searching on this forum and checking out a bunch of stuff here's what I know:

Battery is fine-lots of juice

Checked all the obvious stuff-kill switch, stand, gear selector etc.

Checked all the fuses-all fine.

I do not get the whine from the fuel pump when I turn on the key but if I jumper the relay it runs and pressurizes just fine but still won't start.

Checked the main relay on left side by start solenoid and redid a crappy repair of the diode just for preventive issues and the relay does what it is supposed to do. Power is delivered to the fuel pump relay etc. but after tracing the wiring it seems that control of the fuel pump relay is by the ECU and it's not giving the signal to energize.

Jumpering the fuel pump relay (pump pressures up) gives no joy. No fuel smell at exhaust. Injectors probably not firing.

No spark either.


I have given the harness a once over for any obvious damage etc. but found nothing. It seems to me as if there is some sort of safety that is shutting down all of the systems. Tip over switch? Something similar?

I'm not familiar with this bike and I don't see anything in the wiring diagram that looks like it would do such a thing. All of the other electrics work fine. The bike was running several weeks ago and it ran fine. I'm stumped. Bad ECU perhaps?

Thanks in advance for the help. I really want to ride my new bike and the weather is 80 degrees. Its killing me!

[PhilAgusta]

sound like possible the hose in the tank loose, open tank cap get the flash light turn on your key see if the gas shooting inside

[Cybeeria]

Thanks but the fuel pump isn't even turning on and pressuring up unless I jumper the fuel pump relay. Then it powers up and builds pressure like it should so its not actually the pump but something in the control circuit that is not allowing the relays to energize from the ECU.

[CAG]

Try changing the latch relay. It's on the right side of the bike under the rear fairing.

The SPR doesn't have a tip over switch.

Did some one install some sort of alarm on the bike?

I would try and diagnose one problem first. You don't have fuel or spark, so get either working and go from there.

[esq'z me]

Side stand switch?

[Cybeeria]

CAG-I thoroughly tested each relay and even swapped them with new. They simply aren't getting a signal to energize from elsewhere.

esq'z me-I read about the problems with the side stand here on the forum so I checked that early on. I checked the switch function and even jumpered the connector but still no joy.

Arrgh!

Thanks!

[Cybeeria]

Sorry-I also looked for an alarm but I didn't find one. But that's what it acts like. Some sort of immobilizer or something.

I understand checking each system separately rather than fighting a battle on two fronts however I do find it a bit strange that I lose BOTH fuel AND spark at the same time. It points to some global failure but then again, I could be very wrong.

How tough are the ECUs in these bikes? Is that even likely at this point?

Thanks!

[CAG]

It certainly sounds like an ECU problem then.

[CAG]

Did you replace the battery or just charge it?

[gotojoe]

My F4 will go through the needle sweep and fuel pump prime cycle from turning key to start position, with the bike in gear and also with the engine kill switch pressed in.

Check the earths..and the one up by the ecu...

Check the ignition switch

The diode is a worry ?

The battery is definitely connected correct polarity ?

Check the voltage drop when you crank the engine..

joe