Out riding on Saturday with a group, a friend of mine just up ahead riding a 1978 Triumph Bonneville hit a dog and he hit the ground hard and was unconcious for about 10 mins. The bike was hard up against him so we didn't want to touch it till the ambulance arrived. We had been very busy on the phone with the ambulance people and making sure he was breathing etc when after some time I noticed the tailight was still on and therefore the ignition was still on. This could have been a bad situation if this bike had a fuel pump still running and it is easy to see why they need a relay to shut off the fuel supply on bikes with fuel pumps. Knowing the problems people suffer with these relay failures can anybody think of a more simple method of shutting the pump down in this situation. I know we all think it won't happen to me but it can
Any pictures of the dawg hit? Just asking :loco: I have seen someone (not me) leave the key ON on a bike and the coil exploded and melted all over the doodes MV. A Bonnie is a gravity feed bike, so it does not need a fuel pump.
Yeah I realize the Bonnie doesn't have a fuel pump but a VFR does and there is nothing preventing a VFR for ending up in a similar situation, this is what concerns me about doing away with the fuel pump relay when they play up, must be another way of cutting the ignition to the pump
Hi Norm I am not sure what VFR FI model you are thinking about here - certainly by the time you get to the 6th gen models they all have a fuel cut relay fitted as standard which is linked via the ECU to various inputs - so if you hit the kill switch or the tip over (tilt) sensor is tripped you automatically shut off the FCR, and the fuel stops flowing. I guess your question relates to an earlier VFR type. Inherently if you throw money and time at it, there is probably nothing to stop you raiding the parts bin and retrofitting a similar set up to that fitted on current models. I know there are folks who choose to disable all manner of safety systems for diagnostics reasons to sort out a problem and get a bike running again. Whether or not it is a good idea to then leave those systems disabled is basically down to your level of foresight. Inevitably there are always going to be a few future candidates for Darwin Awards out there who see all safety devices as the spawn of the devil which need to be disabled as they are an affront to personal liberty. I guess if you are lucky enough to have a hot line to a supreme being and know for sure that you will never be involved in an accident where those systems might be worthwhile then by all means leave them disabled. Over in Europe the need to comply with emission limits means that gravity feed systems are fast disappearing and virtually all new motorbikes have some form of fuel injection with safety systems designed at the very least to shut off the fuel pump in the event of a spill, so the sort of safety issue you encountered, will in time become increasingly rare. SkiMad
Hi Skid, I'm thinking about mine, mine is direct wired and was when I got it, it is an 86 with an aftermarket pump, , not sure if there is anyway of fitting a vacuum switch into the inlet manifolds somewhere or another method of shutting the pump. Any type of tip over switch you can think of, probably need to be some mercury type of switch?
The 86 fuel pump is spec'd at 800 cc/minute flow rate, and the fuel cut relay is tied in to the tach signal of the spark igniter box such that the pump is not turned on unless the engine is turning over. Bypassing the fuel cut relay obviously negates this safety feature. Not sure what direct wired means as far as regulating the fuel level in the bowls, and with respect to a safety cut-off. But some bikes have a tip-over switch, maybe you can find a used or salvage tos and retro-fit it with your pump. This guy was riding right behind me on a twisty road and went off in a corner, key was still on...
+1 on raiding a salvage yard and fitting some sort of tip over sensor to stop the fuel pump automatically when the bike is lying down on its side. You probably want to look for a bike fitted with a simple (two wire type) tip over sensor which has a simple on off action. Perhaps take a test meter with you to check the sensor works OK before purchase. NB - The more complex (3+ wire) sensors are generally designed to interact with an ECU to ensure that once triggered, the power to the fuel pump remains shut off until the ignition key is turned off and then back on - just in case your bike does an amazing cartwheel crash and somehow ends up more or less upright. But given the high current used by the fuel pump don't be tempted to run the supply directly through the sensor, use a relay. something like this should work http://www.ebay.co.uk/itm/02-Suzuki...rcycles_Parts_Accessories&hash=item3f2cd16e31 Most tip-over sensors depend on being mounted in the correct orientation in a fairly central location (typically under the fuel tank). So make sure you take note of how/where it was located on the donor bike and ensure it is mounted in a similar orientation on your VFR. For the relay trigger circuit.. Take power from an ignition controlled positive source to terminal 86 on the relay Run a wire from a good ground to the tip over sensor for the other side of the tip over sensor run a wire to terminal 85 on the relay Modify the current fuel pump wiring as follows.. Locate the positive side wire feed to the fuel pump. Assess where best to cut and then divert that supply so that it passes via terminals 30 and 87 on the relay. Chances are the wire may need to be extended, just make sure the wire attached to the fuel pump should be connected to terminal 87 on the relay with the supply side wire connected to terminal 30 [In essence the sensor will simply control the ground(earth) side of the relay trigger circuit. With the bike on its side, the earth feed to the relay will then be interrupted and in turn the fuel pump power supply which has been diverted to pass through terminals 30>87 will be cut.] Hope that helps SkiMad
Thanks Kenny and Skid, I was surprised at how much power the pump pulls turn the ignition on and it drops my battery voltage down to about 11.5 volts and that is before I start cranking it. I think I saw it drop to 9 volts during cranking.Even with it dropping this low, motor fires straight up. Battery is fine sits at 12.6volts and I often use it for starting other bikes. It is a Motorbatt You would never see these figures if you didn't have a volt meter fitted. You can see why if a motor has dodgy wiring or tired coils or suspect battery it is going to be hard to start. Just because it cranks doesn't mean it will start
I replaced the wiring harness on one of my bikes, I swear the blinkers blink brighter, it starts better, pretty much everything is young again. If you have a doggy motor, carb spray is always a good idea. Checking spark is simple with some of the Thexton Spark Testers. It's simple on paper, but more difficult "hands-on" sometimes. :loco:
Taking power straight to the coils from the battery through a relay reduces the voltage drop you get through the wiring loom particularly with an old wiring loom and switches
Hi Duccy, Tanks for asking, he is going ok been out of hospital for a few days very sore and walking around slowly but at least he is walking, his face is black and blue, they took some stitches out yesterday. Could have been much worse. Thanks again. Cheers Norm
Thanks Duccy, he will be ok he was saying this morning it hasn't put any fear into him it is just that at 72 you don't bounce like kid anymore. I suggested he should take up knitting but the look in his eyes made me think that was probably not going to happen
Safety ?? But what about your safety when the pump relay fails and stalls you in the middle lane of a busy freeway, miles from home, in the dark, while it's raining and you have a hot date just waiting for your **** ?? No relay=one less thing to fail. Turn key off if bike goes sideways, common blinkin sense. :eagerness:
Squirrel, that is fine in 99% of situations but in this case Nev was unconcious when we got there, not sure how many seconds behind we were and it was probably 5 mins before I realized the ignition was still on. I guess if it had a fuel pump we would have heard it running and turned the ignition off, but every situation is different and this is why manufacturers have to build in safety devises or they would get their arse sued off. There has to be a better way than the existing relay because they fail, but then again they are getting a lot of age up and you have to expect them to fail
You will find it marked as FCR (Fuel cut relay) on this diagram .. http://www.lifford-cooke.com/motorbiking/documents/VFR VTEC PGM-FI Diagram 2002.pdf SkiMad
