Hello everyone,

I've got a 2003 600 F4i, was previously a stunt bike and ran like a kitten. Restored it back to factory (for the most part) and rode it for about 3 months every other day. First group ride, get a flat in the rear, and as I'm limping down the highway, the bike randomly sputters out and dies, and refuses to fire since.

I've replaced a good handful of things, but still can't seem to get it fire.

-Fuel pump primes after turning ignition on.
-All lights are swell
-Cranks hard all day, smells heavily of fuel from the tail, injectors are spraying
-Tank is about half full, fresh fuel
-Oil is low for the record

Replaced the following already:
-IPG (right side cover, red plug, two wires)
-Crank Sensor (left side cover, white plug, two wires)
-Rectifier
-All new spark plugs
-New battery
-Neutral Saftey Switch (Neutral Switch)

Tested the following:
-Pink wire off ignition is reading 9.3-9.4V after key is turned
-BAS is bypassed (has always been, headlight fairing isn't even on the bike currently, just jumped the plug)
-Kickstand is not bypassed, but working
-Clutch safety switch, not bypassed, but working, or appears to be
-All fuses seem fine, unless I've missed some
-Relays are both clicking, and have been replaced and checked with others
-Resistance on all coils comes back at 11k which is within spec from Honda
-Run switch is "bypassed". When turning the key on, the bike is always set to the run position. So after turning key, pump primes and bike is ready to be started
-I also ran a resistance test on the stator, between all 3 wires, and came back within spec.

I'm running out of ideas, and running out of nice weather for this season. Considering it randomly died after running just fine that entire week, I can't seem to put my finger on anything in particular. Does anyone have anything I can check? Or have any ideas? It's been stuck in my living room for months and I'm getting less motivated every time I try something new that doesn't seem to work.

 

The heavy fuel smell leads me to think the FPR is bad. Did you check that for internal leaks? Did you check for actual spark? What did the plugs look like? Did you check fuel pressure?

 

I tested the FPR by pulling off the other side to see if it leaked while cranking, and it seemed to hold up okay.
Checked for spark on all cylinders by pulling the spark plug and grounding it to the block and firing. No luck on any of them, and plugs looked rough prior to changing, but are brand new now.
I haven't checked fuel pressure yet, since I smelt so much fuel and wasn't getting any spark I figured that was the main cause. I wasn't even able to push start it in second gear, wouldn't actually fire over.

 

Check the power circuits from the ecu to the coils.

 

I checked the voltage going to the coils while cranking. It showed about 0.8V.

The IPG (red connector, right side) showed 0.6-0.7v while cranking.

 

0,8 volts seems very low.
Normally I would expect pulses of 12V.
However how dit you measure this, because measuring the pulses can be quite tricky without oscilloscope.
I would personally look for a common thing for all 4 cylinders.
Don't look into any safety system, because they normally prevent you from cranking the engine.
My money would be on the timing sensor of the iginition.

However if you really have a pulse of maximum 0,8V that definitely is a problem.
Normally the coils should have constant power and then when the power is interupted on the primary side you get a peak of 120V, this leads to a secondary spark of about 12kV.

And for encouragement: First make sure you got the basics: air, fuel, spark. After that it should run (even though it can be really crappy, but that is step 2)
Keep going!
I hope you find it soon.

 

Did you ever figure out what was wrong as I've got those symptoms with the same model and year?

Many thanks

 

Not running bike can be caused by any number of things:

- bad ignition-switch
- bad ignition-switch diode (ALL guides on internet have you installing diode backwards!)
- bad BAS ground wire
- bad BAS
- bad wire between BAS and engine-stop relay
- bad start/stop switch
- bad wire between battery and engine-stop relay
- bad wire between start/stop switch and engine-stop relay
- bad engine-stop relay
- bad wiring between engine-stop relay and fuel-pump relay
- bad wiring between engine-stop relay to injectors
- bad wiring between engine-stop relay to ignition coils
- bad wiring between ECU and fuel-pump relay
- bad wiring between ECU and injectors
- bad wiring between ECU and ignition-coils
- bad wiring between clutch-switch to ECU
- bad wiring between neutral-switch to clutch-diode
- bad wiring between clutch-diode to ECU
- bad wiring between kickstand-switch to ECU

So there can be many areas that can cause bike to not start and run. Need to pull out meter and measure each and every one of those possible problem areas and verify it's either good or bad. Usually it's wiring problem and ALL parts are perfectly good.