Testing Reserve Switch Function

[wco56]

Hello all. I hope your new year is going well.  I have an 86 FJ1200 and I am looking for way to static test the reserve function on the bike. I'm in NY so its way too cold to take it and ride until I run out. I know a lot of you have eliminated it all together, and I had a fuel valve issue with it holding vacuum, but I was fortunate enough to find an NOS petcock online so I grabbed it (and safety wired it before installing). The old one was working thanks to Old Rider's silicone sealant fix and its now my backup, but this one was new so I grabbed it. Since the parts are in there I would like to see if they work, and I was hoping someone has a thought on the testing process. The fuel gauge works and the reserve switch is in place but I was reluctant to just throw 12v at it to test it. Thanks.
Wayne

[fj1289]

Can you start it up with the gas cap open, reach in with a coat hangar (or other metal wire) and gently push down o  the fuel float arm?  Then see if it cuts out?  Switch the reserve switch on and try again?

[Old Rider]

Hi i have tested it on the bench just by using a spare battery 12v . It makes a clunking sound if it works.You can add a fuse on the wire to make sure it does not brake but i not sure if that is needed.The one i tested woks fine on the bike after the test.Can also test it on bike but i don't remember how to test it that way i think it is just to toggle the kill switch and listen if it makes a clunking sound.

[wco56]

Can you start it up with the gas cap open, reach in with a coat hangar (or other metal wire) and gently push down o  the fuel float arm?  Then see if it cuts out?  Switch the reserve switch on and try again?

I actually had thought about doing that but I didn't want to do anything that might damage the float and sender unit. I might give it a try though. Thanks.

[wco56]

Hi i have tested it on the bench just by using a spare battery 12v . It makes a clunking sound if it works.You can add a fuse on the wire to make sure it does not brake but i not sure if that is needed.The one i tested woks fine on the bike after the test.Can also test it on bike but i don't remember how to test it that way i think it is just to toggle the kill switch and listen if it makes a clunking sound.

I think I will do a practice run on the old one while it is on the bench and see how it goes. I should be able to unplug the one in the tank and test that next now that I know that I won't damage it. I was pretty sure 12v would not damage anything but I didn't want to test it that way without asking someone who had done it before. Parts are getting hard to come by on these older bikes. Thanks Old Rider.

[ribbert]

....I was hoping someone has a thought on the testing process.

The best way to test something is in situ, that way you get to test the whole system not just the component. There are a number of ways to test the reserve switch depending on experience and tools at hand. Probably the simplest way is with the motor running and the fuel switch set to main tank press the sender unit arm down with a wooden or plastic stick. The fuel pump should now have no power to it, now flick the switch to reserve and power to the pump should be restored. That's it. If that works there is no need to look further, you have confirmed it works as designed.

The presence of power is most easily determined using a test light (or simply feeling/listening for the pump to start ticking again) and probing the live wire, I know multi meters make folks feel more like a mechanic but trust me, test lights are better for many reasons (and it is what the mechanics and auto elec guys use). It's probably easiest to probe the first connector back from the pump with is only a couple of inches away.

The reserve switch is nothing more than a simple rocker switch and good quality one at that and failure is uncommon. With all the other means of monitoring fuel level, it's not unusual to find owners who leave the switch on reserve permanently which can lead to dirty contacts when returned to service. In this instance a simple clean can restore function.

With the fuel gauge, the low fuel light, the odometer (trip meter), the ease of a visual check through the fuel cap and in many cases, a Garmin fuel gauge and odometer as well, I figure if all 6 of those fail to alert you to the fact you need fuel, perhaps you shouldn't be out unsupervised, let alone riding a bike.

Modern cars and bikes have a fuel gauge and low fuel light only and people seem to survive.

The mileage left when you need to switch to reserve isn't much anyway and I have found on many occasions, it would not have been enough to get me to the next servo (gas station)

My reserve works perfectly, even after many hundreds of thousands of km's, but I rely on my trip meter, it's simply a case of knowing how many Km's I get per tank, which remains pretty constant no matter how I ride. I just reset it at every refill and at a glance I know how exactly how far I have left, dead simple.

Having said all that, I still like it working because it's there and it should!

Noel

[Pat Conlon]

....I was hoping someone has a thought on the testing process.

The best way to test something is in situ, that way you get to test the whole system not just the component. There are a number of ways to test the reserve switch depending on experience and tools at hand. Probably the simplest way is with the motor running and the fuel switch set to main tank press the sender unit arm down with a wooden or plastic stick. The fuel pump should now have no power to it, now flick the switch to reserve and power to the pump should be restored. That's it. If that works there is no need to look further, you have confirmed it works as designed......

Noel, you overlooked something in Wayne's post....

I have an 86 FJ1200 and I am looking for way to static test the reserve function on the bike......

[ribbert]

Noel, you overlooked something in Wayne's post....

Haha, relish the moment Pat, whatever it was.

Noel

[wco56]

....I was hoping someone has a thought on the testing process.

The best way to test something is in situ, that way you get to test the whole system not just the component. There are a number of ways to test the reserve switch depending on experience and tools at hand. Probably the simplest way is with the motor running and the fuel switch set to main tank press the sender unit arm down with a wooden or plastic stick. The fuel pump should now have no power to it, now flick the switch to reserve and power to the pump should be restored. That's it. If that works there is no need to look further, you have confirmed it works as designed.

The presence of power is most easily determined using a test light (or simply feeling/listening for the pump to start ticking again) and probing the live wire, I know multi meters make folks feel more like a mechanic but trust me, test lights are better for many reasons (and it is what the mechanics and auto elec guys use). It's probably easiest to probe the first connector back from the pump with is only a couple of inches away.

The reserve switch is nothing more than a simple rocker switch and good quality one at that and failure is uncommon. With all the other means of monitoring fuel level, it's not unusual to find owners who leave the switch on reserve permanently which can lead to dirty contacts when returned to service. In this instance a simple clean can restore function.

With the fuel gauge, the low fuel light, the odometer (trip meter), the ease of a visual check through the fuel cap and in many cases, a Garmin fuel gauge and odometer as well, I figure if all 6 of those fail to alert you to the fact you need fuel, perhaps you shouldn't be out unsupervised, let alone riding a bike.

Modern cars and bikes have a fuel gauge and low fuel light only and people seem to survive.

The mileage left when you need to switch to reserve isn't much anyway and I have found on many occasions, it would not have been enough to get me to the next servo (gas station)

My reserve works perfectly, even after many hundreds of thousands of km's, but I rely on my trip meter, it's simply a case of knowing how many Km's I get per tank, which remains pretty constant no matter how I ride. I just reset it at every refill and at a glance I know how exactly how far I have left, dead simple.

Having said all that, I still like it working because it's there and it should!

Noel

Noel, thanks for the info. As Pat mentions, I don't have the fuel pump version but I think I can accomplish pretty much the same thing using your suggestion. I will have to wait a bit until it warms up here in the northeast US and then I'll give it a try. I did test the rocker and I know that is working and the reserve function is working in the petcock so I know I am good there as well. I also know the fuel light bulb is good. I have the bike up on the lift table doing some clean up (and it's cold as hell outside right now) so I will try when it gets a little warmer out. I guess the only question I would have is why wouldn't this work just turning the ignition on and pushing down on the sender arm? Why does it need to be running as opposed to just being powered up? Thanks again.

[ribbert]

Noel, thanks for the info. As Pat mentions, I don't have the fuel pump version but I think I can accomplish pretty much the same thing using your suggestion.

You're right, the same diagnostic process applies. If the system works with everything connected, no need to look any further. If it doesn't, then you start testing components individually.

The engine running question you have is specific to the fuel pump model. The pump times out after a few seconds from when the ignition is turned on if there is no engine start so just ignore that.

Noel

[wco56]

Thanks Noel. Much like you, if the parts are in there I would like them to work properly. I also reset the trip meter and use that as my de facto fuel gauge since most of my bikes are older and don't have a fuel gauge. I grew up on bikes with no gauge, and some without a trip meter as well. Ride safe, and thanks for the info.
Wayne