Curiosity killed the FJ

[ribbert]

I always run my bike to reserve unless out in the country. Cruising along at a steady 100kph today the the motor started to falter signalling the need to switch to reserve. In light of recent discussions I was curious about its behaviour and allowed it to continue, something I have never done before. I was playing with the throttle and tuned in to what it was doing. Not long after the motor died completely and I switched to reserve but it wouldn't start so I rolled to a stop at the edge of the road. Tried starting it again, nothing. One more time, nothing.
Not one to persist with cranking if it isn't firing, particularly on my own machine that I know always starts instantly, I set to thinking. It took about a minute.

I had run it dry and when the motor stopped, so had the fuel pump.

A further 3 or 4 cycles of ignition on/off until the fuel pump settled down with full carbs and it started first flick of the button.
If I had switched to reserve while the engine was just running rough, but still running, the fuel pump would have caught up.

Noel

[markmartin]

Good one Noel.   

[Mike Ramos]

Uh, Patrick.... 

Calling Brother Patrick.......!

[Pat Conlon]

 Hey Noel....yep, that sounds familiar....

So if I read the explanation correctly, if they do not flip the reserve switch or it malfunctions the fuel pump does not turn on and the bike runs out of fuel?

Yep, it happened to my buddy Paul....the first time he rode my '92.
I forgot to tell him about the reserve switch. He was riding in front, the bike started sputtering, he slowed down thinking something was wrong and ended up stopped by the side of the road with a dead engine.
His comment was "shit the fuel light just came on...that's not much of a warning.."
Flipped the switch to 'R' ....the fuel pump started clicking....and away we went.

I totally forgot about the switch because my '84 does not have one....

[AustinFJ]

Sounds like normal fuel pump behavior to me.   If I have worked on my carbs (drained the bowls) and want to fire up the bike, I have to cycle the ignition on and off a few times before the bowls fill up.   Seems the pump will only run at 'full tilt' for a few seconds before shutting off. (a safety circuit perhaps?)  Once there is some resistance, it runs normally.  I think if you sat and cranked it long enough, it probably would have filled the bowls and started.  But I have the same aversion to endless cranking that you do.  If the bike has been sitting for a few days or more, and I go to start it and hear the fuel pump run and then stop after I turn on the ignition, I cycle it again until I hear the pump slow down before stopping.   Bike fires immediately with full bowls.   

[Bminder]

All the times Randy made me pull my carbs and clean my pilot jets, I would cycle the key on and off until the fuel pump quit running, so I knew the bowls were full. It always amazed me how quickly the bike would fire up.  Wasn't like trying to start a carbed car that had run out of gas, guess cuz the tank and the pump are only inches away on the bike...

[movenon]

Sounds normal to me also. She ran dry. Not the same but when I change fuel filter in my diesel I have to cycle the ign. switch 5 or 6 times to get the filter bowel filled and pressurized. On occasion you wonder if it is going to start... The 50's vintage low 15 PSI carter electric lift pump on it (99 Dodge) isn't much more sophisticated than the FJ pump.
Good test of the system Noel. If I did it with, my luck I would end up alongside the road with a a malfunctioned switch and my tank would be bone ass dry

A trivia matter as I am cleaning out a tank I have the fuel float and fuel tap out of the tank. The post 1989 fuel tap has a screen inside the tank but it is pretty small. The screen filter in my 1990 measures out at 1/4 " (6.35mm) in diameter and 1/2" long (12.7mm).... Pretty tiny. Here is what it looks like.



With age of our tanks it might be beneficial to pull that tap (2 JIS screws) and take a look at it sometime when you are low on fuel and in the maintenance mood. Because I am cleaning a new tank out my plan is to put a external screen filter (cleanable ?) in the line ahead of the factory Yamaha filter. In fact I am giving some thought as to eliminating the tiny in tank screen and keeping a larger external screen in the system.
From the pictures I have seen of the gravity feed screens, they are longer and more screen area.

George

[Pat Conlon]

Yea, the gravity fed bikes have larger petcock screens...but....I would trade that for a real fuel filter any day.

[FJscott]

Am I wrong in thinking the reason the peacock screen is in the tank is to prevent and protect the peacock valve itself from being fouled?

[FJscott]

I have been having a problem with my 92 where it's been cutting out the fuel pump to switch to reserve prematurely. Does this consistently at 1/2 tank indicated on the gage. Or about 1.8 gallons from full.
Is this adjustable? Another question is there are no wires to the peacock indicating there was a reserve solenoid valve so what does the reserve switch do other than reactivate fuel pump circuit?

Thanks,
Scott

[movenon]

Am I wrong in thinking the reason the peacock screen is in the tank is to prevent and protect the peacock valve itself from being fouled?

Yes I agree, that is the only thing keeping me from removing it. I do wish it was larger though. I am of the opinion that the fuel screens and filters are becoming more important to maintain because of the aging tanks and to some degree the fuels we have today.

I learned a little by cleaning my tank. First they a very hard to clean if you want to protect the outside paint job. Most of the "crud" was on top side of my tank, not as much on the bottom. I don't think the top of the tank gets "washed" with fuel as much and also condensation can happen there. With the tank "full" it still has an air space there. Because of the way the tanks are designed there are 2 tapering wings about where your knee's rest. Perfect place for crap to accumulate (below the screen filter level). Even with the fuel cap, fuel shut off and float removed it is real hard to inspect inside the tank especially the top back section of the tank. I worked on mine for about 5 days off and on and got it about as clean as I can get it but I am sure some small crap will continue to flow for a while. That's why I will double filter. Fist filter a larger screen filter and the second a stock Yamaha filter (and carry a spare). 

I am not an ethanol fan but the one redeeming grace is that alcohol is a solvent and in time will probably stabilize the cleanliness of the fuel system.

My opinion is check the fuel petcock screen at least once every 20 years... and change the fuel filter every year. If your FJ is running fine, don't even think about cleaning your tank as it will probably just cause a problem. 
George

[movenon]

I have been having a problem with my 92 where it's been cutting out the fuel pump to switch to reserve prematurely. Does this consistently at 1/2 tank indicated on the gage. Or about 1.8 gallons from full.
Is this adjustable? Another question is there are no wires to the peacock indicating there was a reserve solenoid valve so what does the reserve switch do other than reactivate fuel pump circuit?

Thanks,
Scott

It just reactivates the fuel pump.

As to adjusting the the sensor, I am not sure I have to correct answer but here is a picture of the float and sensor. Next time you go into reserve take a bright flashlight and try to see where that silver sensor is. If you were to lower it I think it would come on later ? 

At least you know what it looks like 
George

[FJscott]

Good info, thanks

[racerrad8]

George

George, if you need a new screen I have them here; 89-93 Fuel Tank Petcock w/ screen

You will also get a new o-ring seal to make sure that old, hard, flat one you currently have does not leak, plus you will get the new internal o-ring that prevents fuel from leaking around the petcock shaft.

Randy - RPM

[FJscott]

Am I wrong in thinking the reason the peacock screen is in the tank is to prevent and protect the peacock valve itself from being fouled?

Yes I agree, that is the only thing keeping me from removing it. I do wish it was larger though. I am of the opinion that the fuel screens and filters are becoming more important to maintain because of the aging tanks and to some degree the fuels we have today.

I learned a little by cleaning my tank. First they a very hard to clean if you want to protect the outside paint job. Most of the "crud" was on top side of my tank, not as much on the bottom. I don't think the top of the tank gets "washed" with fuel as much and also condensation can happen there. With the tank "full" it still has an air space there. Because of the way the tanks are designed there are 2 tapering wings about where your knee's rest. Perfect place for crap to accumulate (below the screen filter level). Even with the fuel cap, fuel shut off and float removed it is real hard to inspect inside the tank especially the top back section of the tank. I worked on mine for about 5 days off and on and got it about as clean as I can get it but I am sure some small crap will continue to flow for a while. That's why I will double filter. Fist filter a larger screen filter and the second a stock Yamaha filter (and carry a spare). 

I am not an ethanol fan but the one redeeming grace is that alcohol is a solvent and in time will probably stabilize the cleanliness of the fuel system.

My opinion is check the fuel petcock screen at least once every 20 years... and change the fuel filter every year. If your FJ is running fine, don't even think about cleaning your tank as it will probably just cause a problem. 
George

I just changed my filter. When I did I noticed the fuel lines felt like a partially frozen garden hose. They were stiff, brittle and crunchy when you bend them. I believe this is from the ethanol/ alcohol drying out the rubber.
I replaced all the fuel lines with marine grade fuel line rated for ethanol use. Same lines used in my yamaha outboard motor.