Have any of you added an Aux Tank to a 2020+ RT?

[Leroy73]

I did do what I call a "proto type" test. I filled both tanks as full as I could get them, then rode 250 miles as fast as the speed limit would allow, some 75mph. I visited friends, then returned the 250 miles after refilling the tanks. No problems. I will be adding a shut off valve so that I can easily take the aux tank off if needed. I do have an inline fuel filter on the Aux tank line.

I leave in the morning at 0500 for Western Colorado. That will be a "real" test.

These machines mpg is influenced greatly by mph and wind. I can get near 40 mpg at 50 mph with no wind. Increase to 75 mph, 32 mpg maybe. Throw in a wind and 28 mpg looks good. There is a lot of frontal area.

My good ol' VTX 1300R was very consistent. MPG did drop some with speed, or should I say increased with less speed. I did drop some mpg with wind, but not enough to make me walk. But it had no fairing, just a windshield, and chaps on the highway bars.

 

[Leroy73]

Aux Tank Up Date:
I just returned from a 2600 mile trip to Colorado and New Mexico. 106°F on the return. Everything worked fine until on the way home at the 106°F temps, when I guess I had a vapor lock in the Aux line. Only half of the aux tank made it to the main tank. By morning, all of the fuel had transferred. I'll need to reroute the lines and/or insulate. On the way out, I ran into over 100°F temps with no problems. Maybe 105°F is the limit. LOL

In the mountains, my MPG was 40+mpg. Slow speeds. At one point, just after a fill up, I saw 300 miles to Empty on only the main tank. That didn't last long.

 

[racoon]

In the mountains, my MPG was 40+mpg. Slow speeds. At one point, just after a fill up, I saw 300 miles to Empty on only the main tank. That didn't last long.

Most likely due to the ECU adjusting the air/fuel ratio due to the change in air pressure at the higher altitudes.

 

[jdgretz]

@jdgretz I think that pump idea and arrangement works well. I would adapt that to the tank up high on the pillion seat area, get a metal shop to make the replacement mount cover to be sturdy, tank easily removed and not worry about filling one before the other etc. Def use an evap tie-in to relieve tank pressure and vapors as it would be in the sun a lot. Plus with a 5 gal tank, you would get near 500 miles before having to fillup both tanks. That would work for me.
@jdgretz what pump and plumbing did you use?

Sorry to take so long to get back to this. I now am the proud owner of a slightly used (28 miles on the clock) 2024 Spyder RT Limited.

The Goldwing used a small Carter Marine style pump that is around 20gph flow rate. Steel braided fuel lines with a quick disconnect at the aux tank (Summit Racing). The whole thing was wired to a lighted switch on the side panel. The tank came from Summit Racing and was foam filled to prevent sloshing (basically a dragster gas tank).

Looking at the maintenance manual for the Spyder, it looks like I might be able to put a "t" fitting into the fuel return line on the pump. I'm thinking the Show Chrome trailer hitch along with their Cooler Luggage rack may be the right setup for what I want to do. Need to figure out the fuel line routing so that the flexing of the suspension doesn't mess with the fuel lines.

jdg

 

[Snoking1127]

From my service manual:

P0443 ECM Canister purge valve open circuit
P0458 ECM Canister purge valve shorted to ground
P0459 ECM Canister purge valve shorted to battery +

I believe that if you just leave the purge solenoid plugged into it's electrical connection, the Spyder will not know what is going on with the canister and hoses. Or the solenoid can be removed and a resistor inserted, taking place of the solenoid. Measure the resistance of the solenoid and get a resistor of the same value. I know there are bypass kits available for Kawasaki motor cycles that have the resistor in a plug to take the place of the solenoid and rubber plus some that go in the throttle bodies/intakes.