Fuel supply

[Clyde K.]

Good evening all, it is me again. I rigged up my 78 1100e fuel lines, with filters and automotive line routed as per the post in mods: fuel & carb. My problem is that the fuel doesn't flow in PRIME position. What did I do wrong?

[CatatonicBug]

When you turn the knob to "prime", which direction does the arm point? Forward or to the rear of the bike? Next question, if you look at the part of the petcock that actually turns, there should be a letter stamped into one or both of them (L/R) to tell you which side it should go on. There is a chance that either the petcocks themselves were swapped on the tank, or the valve piece was swapped between the petcocks. The arm should point to the rear for Prime IIRC.

[Clyde K.]

Thanks CatatonicBug, but I didn't have the petcocks apart. Fuel flows freely without the fuel line in Pri. It is currently 20 degrees here so I won't be working on it today anyway. I appreciate the reply. R/S, Clyde

[CatatonicBug]

Maybe it's time to take them apart. For all you know, the inner rubber valve piece has fallen apart and covered the hole for the Prime outlet. It was 21º today when I rode to work, and I'll be installing a fork brace tonight.

[DGXSER]

Fuel flows in prime when not connected to fuel line, but no flow when connected. This is a standard, does it have standard tank and petcocks? Did someone throw an Octy valve on your standard and its piped backwards?

Otherwise, sounds like soemthing made a nest in your fuel line and has it plugged.

[skids]

Only one of the petcocks is labled for the side it goes on. Yeah like he said the handles point towards the rear when in prime, forward when in reserve, down in the automatic vacuum mode. If your petcock handles were switched, the positions for flow are not intuitively backwards! I doubt that the holey gasket rotated out of position because the holes are real close together and you would have gas on the floor for sure. I would suspect that the handles are reversed...

[skids]

PS, it is good to have the free ends of the hoses where you can get to them quick if fuel starts flowing for some reason and you cant get it off again. I thing golf tees work good as temporary plugs to the hose ends.

[skids]

I remember a long time ago when one of the members wanted an "off" position to his standard petcocks and plugged the repective oriface with something. I believe that his prime setting was an off setting after that.

[natemoen]

I remember a long time ago when one of the members wanted an "off" position to his standard petcocks and plugged the repective oriface with something. I believe that his prime setting was an off setting after that.

You can also just file the little stopper tab on the face plate off so you can turn the petcocks handle in an upward position on the standards, much easier. I had to file a little bit off the handle so it didn't hit the tank but it was not much.

IIRC I think the person that turned the prime position into an off position did that as a part of him also getting rid of the vacuum function of the standard petcocks as well. He soldered in the orifice on the back side of the selector handle.

[Rasputin]

You can also just file the little stopper tab on the face plate off so you can turn the petcocks handle in an upward position on the standards, much easier. I had to file a little bit off the handle so it didn't hit the tank but it was not much.

I also did this and It is so nice to know that when you park for an extended length of time it is a solid shut-off. No worries unless your petcocks are shot anyways. I did not have to file any off the handles on mine but it is a very tight fit without doing so.

[Clyde K.]

Guys! Guys! Thanks for the input. I rebuilt my petcocks using new parts when I first got the bike back in August of 2010. I did them one at a time just to make sure I didn't get anything confused. I also inspected each part to ensure no one else had mucked them up. Additionally, I have had it running and ridden numerous times since then with no problem. I cleaned the carbs for the unteenth time, with air and carb cleaner, and teeny tiny wires. It was runnin ok with the bench synch but note quite right. I bought a 4 gauge synch set and got it running like a scalded cat (yes, I have seen a couple in my 65 years on this earth). I figured that since I had a couple of bucks I would try the fuel line and inline filter mod you guys raved about. I printed the diagram provided in the post so I had it in front of me when I did it. I turned the tank to prime because I still had the synch gauges hooked to the vacuum lines for the fuel pump, and no fuel. I pulled the lines from the petcock to the filters and over an open container turned the petcock to PRI and copious amounts of fuel flowed. I tried gently blowing through the filter and remaining fuel system with no success. I really appreciate all of your insights, and since I obviously ran the lines correctly, I will now address the area from the filter to the floats, could be an air lock or something. I live in the mountains in Northern Idaho and we have 2.5 feet of snow on the ground. I also have a carport and not a heated garage or shed to work in. Up here we old wusses put chains on our boots to get around 'cause the bikes don't do well in the snow (can"t find any studded tires in my size). I did just come back from town with half a dozen tarps to use as walls and a door, and an electric heater, so I can work on my bike in 20 degree weather like CatatonicBug.

Again thanks for all the input, and I will let you know what I figure out. Respectfully submitted, Clyde K. GySgt USMC(Ret)

[TopCatGr58]

I tried gently blowing through the filter and remaining fuel system with no success.

Hey Clyde,

What type of fuel filters did you get? I've used those nifty little cone shaped ones from the auto store/lawnmower type, but their shape is not intuitive.
I first tried them with the flow going from the large end thru to the small end, then when it didn't work, I LOOKED at the filter, and saw the ARROW going the other way, from the pointy/tapered end towards the large round base end! JAT!?

T.C.

[Clyde K.]

PS: natemoen and Rasputin. Thanks for the tip on the "OFF position" mod to the petcocks. I thought about that when I had them apart in Aug, but decided to experiment after I knew it would run (it was a $300 basket case, after all. Clyde

[Clyde K.]

Thanks TC. Good point. I pulled both filters this morning and can blow through in both directions, but like yours the arrow points from the small end to the large end. It is supposed to be 25-30 degrees tomorrow so I will jump in my cold weather gear and tinker. First thing is to pull the bowl plugs and try to blow through fuel lines. That failing, I will pull the carbs again. Clyde

[TopCatGr58]

Hey again,

Are the float bowls already full of fuel? If so, then the floats would have been keeping the valves shut, and you would NOT have been able to blow thru them anyways.

Okay, if this is the diagram you're talking about?....



This was made many years ago, showing much larger fuel filters. If you have the small ones, then you probably don't need to wrap the fuel line AROUND/UNDER the intake mounts, but just run it across the top from the petcock to the opposite fuel T, so that it has a more direct straight path. That's how I have mine run, just on top of the intake boots. Yes, the filter will be on it's side, but it flows and filters just fine.

T.C.