Sorry it took so lengthy to get again to you. Life acquired in the best way. 
The very first thing to do is take away the gas cap meeting. Open cap and take away the 4 phillips screws within the cap base. These phillips heads can strip out simply, so ensure you have a non-worn, good becoming screwdriver. Put all of your weight pushing the screw driver down into the screw whereas turning till it’s damaged unfastened. Take away the cap meeting. It’s a good suggestion to cowl the tank with 2 layers of towels with a gap within the center to entry the within of the tank. This could forestall paint harm from dripped gas.
Be aware that there’s an open slot within the cap base between the 2 left screws. This aligns with the outlet within the tank between the 2 left screws. That is the cap rain drain that retains rain water that collects across the cap from coming into the tank. There’s a tube contained in the tank that drains the water out the underside. When reinstalling the cap, the hinge MUST be in the direction of the rear of the bike to permit the drain to work correctly.
The tank is aluminum, so the within of the tank SHOULD be vivid shiney silver. If there seems to be a light-weight brownish bathtub ring on the decrease a part of the tank, that’s the first indication of the pump damper breaking down.
The subsequent factor to do is drain the tank. The tank will NOT gravity drain by merely eradicating the hoses from the tank because of the routing of the tubing contained in the tank. Sure, a bit gas will come out, however not the bulk. One of the simplest ways to empty the tank is with a switch pump. An excellent cheap one might be purchased from Harbor Freight or Summit Racing. I’ve a few the Harbor Freight ones that I’ve used for years with nice outcomes.
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After draining the tank, once more search for discoloration beneath the gas stage.
Subsequent, it would be best to take away the gas pump. It’s mounted to a shelf contained in the left entrance of the tank. Half #4 in Rob’s picture above has a clip on the entrance and rear of it that holds the pump all the way down to the shelf. It releases by urgent each tabs in the direction of the pump.
There have been two totally different gas pumps that got here on the Flying Bricks. The 52mm pump was used on bikes constructed earlier than 1/93 and the 43mm pump that was used on bikes constructed after 1/93.
The pump on the left is the 52mm pump with the very delicate “cup” inlet display screen. The pump on the suitable is the 43mm pump with the extra strong “sock” inlet display screen.
If you wish to know which pump you may have earlier than eradicating it, search for these wrinkles within the housing on the high of the pump. If it has the wrinkles, it’s the 52mm pump with the fragile display screen. Be VERY cautious whereas lifting this pump out of the shelf in order to not tear the display screen on the cup. If it doesn’t have the wrinkles, then you may have the 43mm pump (or maybe a 37mm aftermarket pump) with the extra strong sock filter. The one difficulty with that’s it requires a bit extra manipulation to get the sock by the outlet within the shelf, however it shouldn’t tear.
BEFORE eradicating the pump, have a 6mm and 7mm wrench (or a tiny crescent wrench) readily available to take away the wires as soon as the pump is out of the tank (the wires are lengthy sufficient).
Take an extended screwdriver or a 7mm nut driver and take away the hose clamp from the quick hose that’s related to the gas filter. Disconnect it from the top furthest from the filter and go away the clamp on the tube within the tank. Disconnect the hose from the tube. Drain as a lot gas as you may from filter into tank.
Now, carry filter and the connected hoses straight up out of the tank till the hose is tight. Now attain into the tank with the opposite hand and grip the 2 tabs in entrance of and behind the pump. Squeeze them collectively, towards the pump to launch them from the shelf.
Use the hand on the filter to supply the lifting and the hand within the tank to information the pump by and away from the shelf. As soon as away from the shelf, take away the hand from the tank and carry pump out of tank. Disconnect wires as soon as pump is exterior the tank. Small terminal is optimistic and huge terminal is floor. You do have the important thing off, proper?
Take pump to bench and take a look at with a battery. Simply briefly contact wires to acceptable terminals. If it doesn’t flip over, strive briefly reversing polarity to see if it is going to unstick. If it may possibly’t be unstuck, you want a brand new pump.
Verify the rubber vibration damper surrounding the pump for deterioration. It ought to have the consistency of a tire with no gooeyness and no switch to your finger. There needs to be no lacking areas across the decrease edge.
Now you get to totally examine the tank. First, with a flashlight and small inspection mirror, examine the properly beneath the place the pump mounts. That’s the place any dissolved pump vibration damper will settle first. Is it clear sufficient to eat out of? It higher be, as a result of that’s what you pump, filter, injectors, and motor will probably be consuming if it’s not!
ALL hoses used within the gas system MUST be rated for gas injection (100 psi+)!!!(Besides the vent hose used on the 54mm inlet display screen)
ALL hoses used contained in the gas tank MUST be submersible rated!!!
Tell us what you discover and we’ll go from there. Who is aware of, you could get fortunate, if nobody has pumped any crud by you gas system. WAY higher to verify first than simply roll the cube.
