The Case of The Non-Venting Gas Tank

[billz410]

Here's a question for you gearheads-

Had the tank off my '08 Nomad and did the 7" filter modification, in addition to reed valve removal and also removed idle control solenoids.

After putting everything back together, I went to put gas in at the gas station and got quite a surprise when opening the gas cap- huge amounts of pressure built up in the gas tank. Not good.

Here's the deal-

On Gadget's website he talks about removing the charcoal canister on CA Emission bikes when doing the air cleaner mod- often done in conjuction with the installation of coaster plates, etc.

He provides instructions to just connect the two hoses going in and out of the canister- making a 'loop' of sorts. However, my left side cover is filled with vacuum servo for cruise, fuse panel, TFi, etc., so canister was completely removed.

You will note on the Vacuum Hose Routing Diagram on the inside left cover that a green-labeled hose from the canister goes to the air cleaner- this hose was completely removed because of the new backing plate from Chuckster.

You then have a blue-labeled hose from the canister which goes to the 'return pump'. This hose I have vented to atmosphere right now. ( I had it plugged- didn't affect the pressurizing of the gas tank.)

Next is a red hose and a blue hose from the return pump that go to the rear of the tank- those are hooked up correctly.

Then there is the white-labeled hose from the return pump that runs up to the throttle body area- also hooked up correctly.

And, at the front of the tank is the 'dribble' hose, for those times you overfill your gas tank. This hose is not plugged.

Any ideas on why my tank is pressurizing? It builds pressure almost instantly when the engine is started- and of course takes even less time to pressurize when the tank is full.

I no ace mechanic, but I just don't see what I can have hooked up wrong in the way of hoses... any of you ever had the your tank pressurize in this manner? It's substantial pressure- very definitely something wrong.



Thanks,