Engine dead on a rc24 vfr 750 f

So today i was riding nicely at about 80/90mph, 6000rpm in 6th gear, everything was fine till suddenly the engine died. While i was slowing down i noticed the rpm counter pointed to zero even if the engine was still turning (but was off, no power), also when i was almost stopped the oil warning turned on. All this happened really quickly, the engine died, it didnt have on off or malfunctions, simply it turned off and i reached the first safe point off the road.

Well the bike until today went very well since i started using it after 5 or so years of stop. Obviously i did all the required maintenance:
-oil, oil filter, all liquids from clutch and brakes, air filter, sparks, radiator liquid.
-water pump new cause it was corroded, and also new thermostat

I also had a experienced mechanic test it because of the noise from the engine (my first bike with gear driven cams), and he said the engine was ok. Not that i had any problems till today, it pulled strong and sound beatiful (even with the ticlking noise of this particular engine).

Right. After the accident, if i try to start the engine nothing happens, i cant even hear the starter turning or doing any noise. Everything works except the engine, but i'm suspecting an electric failure.. Maybe something that made the engine fuse blow?
Hope someone can point me in the right direction!

 

Aggh - not wanting to state the obvious but your description definitely sounds like you have some sort of electrical issue - so start by checking the engine kill switch has not been inadvertently moved to the off position, if that's fine then check the ignition circuits.

If that fails eliminate in turn all the safety interlock circuits which can cause a running bike to shut off the fuel supply - so check kickstand is fully up and then manually operate the kickstand position switch to check it is not giving a false stand down signal to the ECU. Also check the bike is in neutral and that the neutral light is showing correctly when out of gear. Finally give the tip over sensor a gentle tap in case it needs to reset.

Can you hear the fuel pump priming? If no, then check all the fuses especially the main fuse by the battery. Are the gauges lighting up normally when you move the key to the ignition on position? Are the headlights lighting up with the ignition in the on position. Is the FI light flashing some sort of MIL code?

I don't think a bike that old will have HISS, but if it does, then remove (or at least relocate further away) any nearby potential sources of interference like mobile phones - also try the key the other way round just in case the immobiliser cut in. I am assuming it does not have an aftermarket alarm/immobiliser fitted - as they can also provide endless grief.

I cant really offer anything more - without answers to the above..




SkiMad

 

Go to the starter solenoid and check the main 30 amp fuse first. It could be as simple as a bad battery, loose battery terminal or ground wire or a bad r/r that took our some components from overcharging. Oil light and tach are both normal.

Che bella maccina !

 

Thank you for your replies!
Unfortunately my bike is now in a deposit away from me so i ll have to wait thursday to check everything.
Lets start:
Kill switch sure its ok cause when pressed the starter turn but the engine doesnt start, my starter doesnt turn.
I will check every safety sensor as the kickstand!
Anyway the lights, instrument and everything apart from the engine works well!
I have no hiis or aftermarket alarm!
So i will go and check the main fuse and then the one under the rpm counter. I will also check all the wires and my battery, it has some years, but its a yuasa and alwais worked well!
My question is if the main fuse is gone then all the electrics should be off? I see on the service manual that there is a 10amp fuse specifically for ignition and fuel under the tacho.
I know the r/r cause many problems, my one was replaced some years ago (then the bike saw very little usage), but if it is faulty is possible that the bike stop immediately? Or maybe because it burned my battery?

I ll let you know asap guys!

 

I am with Squirrel on this one, starter relay connection in a common problem.

 

Ok so i had time to check everything and the problem is: the fuel pump!
With the pump off the bike starts with no prob, but if i connect it, it burns the 10a fuse of the ignition.
Now my question is, i know there are kit to repair the switch of the fuel pump saving a lot of money, how can i know if it will fix it or if i need to replace the whole fuel pump?
Any ideas?
The pump is short circuited and while i connected it to the battery to check, the body of the pump became quite hot!


The kit in question: http://www.wemoto.it/bikes/honda/vfr_750_fg__rc24/86/picture/fuel_pump_repair_kit_-_point_switch/

 

Ok starting from the premise that one way or the other you are going to have to remove the existing faulty fuel pump - then doing that now makes sense. Then we need to work out if its the switching bit or the pump motor/windings that have failed.

On that website a replacement pump will be 5x the cost of the repair kit. But before deciding which to purchase I suggest you carefully review the youtube video on the website which shows how to install the repair kit (you can turn the music off!). The key bit starts around 3 minutes 15 seconds where they show old and new components side by side and appear to demonstrate what should be happening if the part is OK.

Either way it won't hurt to dismantle as per the video to that point and then inspect closely to see if the switching component shows any signs of damage/failure to operate. If it is obviously jammed in one position or fused/burnt out then you may be lucky and can get away with a repair kit.

One other observation (Thankfully I have never had to mess with a fuel pump) but the video appears to show that once the switch component has been removed, the end of the pump motor shaft is visible. If that is the actual shaft, then it won't hurt to try and see if it will spin freely - you may need pliers to get a grip on it. Obviously if the shaft is seized solid, then when you apply voltage to the motor windings all that will happen is the motor will presumably get super hot - thus confirming the problem is the pump and not the switch control points and you will need to order a replacement pump. So you might consider bench testing the motor bit - with the switch component removed - by momentarily connecting a 12 volt feed across the wires running into the pump body as this will effectively by-passing the switch component. Beware if the pump is good it may attempt to rotate and eject any fuel remaining in the pump body. So for the test its worth wrapping in thick cloth and then nestling it (without crushing it) in the jaws of a vice. If the pump runs fine, then order up the repair kit and you should be good to go.

Hope that helps. Good luck and thanks for keeping us updated.



SkiMad

 

You need to check the movement of the central armature shaft by using pliers to pull it up (about 8mm of movement). If that's stuck for any reason, pump will overheat and pop fuses. The shaft moves in and out in operation with the pumping diaphram at its bottom, does not spin. Not sure what skidmad is referring to.

I don't believe the electrickal contact points are your problem.

 

Thanks squirrelman - as I said I have never had to mess with this sort of pump - so was unsure if it was a simple rotary armature pump or as you describe a diagphram unit. Sounds like the same test should work grab hold with pliers and see if it moves back and forth freely. If its stuck then its time to order a whole replacement pump.