I thought about that. And I thought, what about and extended filler neck? This could be an easily turned up thing that screws into the existing one. The breather pipe (that goes to the airbox and causes oil in the airbox issues when the tank is too full), could then be taken off of this extended filler neck. Hard to see how oil could get up into such an extended filler neck on into the airbox. This would allow more in the tank... hopefully enough to keep the feed outlet submerged.
Great shot Paul . What mods have you got on your bike so far ? Relative to the The oil in air box etc.. ? Rather than look back in the threads if you could bring us up to date ? Personally I would rather deal with some oil in the air box than a oil starved engine. The way you have your feed line routed you have room for the reservoir. It could double as a side mounted oil cooler (kind of) . Or maybe you could go up the steep hill and down some other way ? (not trying to be funny) .
Here are some examples : https://www.amazon.com/gp/product/B0739MQ2GM/ref=ox_sc_act_title_2?smid=A3I7SUY2CP5A5T&psc=1 https://www.amazon.com/gp/product/B07BJZZNDQ/ref=ox_sc_act_title_1?smid=A2Y7J3VVCF64S3&psc=1 You will need a AN to 3/8in. hose barbs like this : https://www.amazon.com/Derale-98201...coding=UTF8&psc=1&refRID=9N7NVQSWRZGG7WM0GFMM
I may just mock this up on my bike to get a good clean look and just to prove it can be done . These will hold quite a bit of oil and should get you down the steep decline .