on vehicles there is a fuel vapor recovery system that takes the gas vapors after fueling through charcoal filter and into the manifold. If one fills tank too full, raw fuel can get into system and mess up the fuel-air metering.
Word of caution on "topping" the fuel tank off is that raw fuel can get into the fuel evaporator system and cause engine issues not to mention messing up fuel relay system.
IMHO that only applies to Spyders with V-twin engines .... any Spyder with the 1330 has a different set-up for fuel and vapor lines ..... Mike :thumbup:
This 2021 RTL is the first one of the 6 that I have owned with a "distance to empty" warning. And I will say that this gas gauge is the most inaccurate of them all. I have had my number of miles to go get below 25 and go to the 3 lines. After traveling another 8 miles or so, the bike only held 5.5 gallons. The other bikes were very accurate. When the low fuel light comes on, that was a given that the bike had 1 gallon left.
I posted my original question thinking that someone knew the answer to the mystery gas gauge. So I asked the question to the BRP customer service. The response was to contact one of the dealers listed in my area. Then BRP asked me if I was satisfied with their answer. You can all guess my response. A BRP customer service supervisor sent me an email with a case number and advised me to contact them if I had any additional questions. So I called BRP and the customer service agent told me that she could not answer any "technical questions". I asked to speak with a tech but only dealers can speak with the tech's. Frustrated I called my dealer and they had a good laugh. I'm waiting for my dealer to call me back. My quest for an answer continues.
I understand what you are saying, and i know the bikes should not be run too low. But of the 6 spyders that I have owned, this gas gauge is definilty the most inaccurate. On all the other bikes, if they are run until the gas light comes on, they will hold right at 6 gallons (that is for the 2 F3T and the 1 F3L that I have owned with the 7 gallon tank.) The similar experiece was had with my 2014 RT. One gallon left when the light comes on. But this 2021 RTL is just different.Don't forget that the 'published capacity' of the gas tank also includes ALL the 'expansion room' in the tank that's purposefully designed into it so that even when you fill it right up, there's still a little air space that allows the gas to safely expand as it warms from its 'in a tank buried in the cool ground' temperature to its 'in a tank sitting in the ambient temp air if not direct sunlight' temperature!!
So even if you turn the bike upside down and completely drain the tank, you should NEVER actually be able to fill it to its stated capacity; and if you do, there's a very good chance that you'll very soon end up with gas spewing out of places you really don't want it spewing out of!! :yikes:
And then there's the fact that these tanks and modern fuel systems are designed and intended to ALWAYS try to retain SOME gas in the tank to keep all those important bits that should remain immersed in sufficient gas to keep them cool & lubed working properly and not self-destructing cos you've run the gas remaining level too low... :banghead:
Hence the 'Distance to Empty' not actually meaning that at '---' there's no gas left in the tank, it's just telling you that there's NO SAFELY USEABLE gas left in the tank, and from here '---' on in, you are very likely causing damage that's irreversible and cumulative to some fairly expensive and difficult to replace items - even if it is only 'microscopic damage', at least initially!!So once again, :banghead:
Besides, because of the various odd shapes of the tanks over the years and the linear operation of the fuel gauges on EVERY MODEL of Spyder EVER, NONE of their fuel gauges have ever really qualified as being called 'accurate' by any stretch of the imagination - the senders simply cannot cater for those odd shapes in any meaningfully accurate way! :lecturef_smilie:
Just Sayin' :cheers:
Ps: I'm pretty sure that the earlier 'Glovebox Manuals' had warnings in them about not running the gas level too much below 1/4, or something like that. There's similar warnings in pretty much EVERY manual I've ever seen for any modern Fuel Injected engined vehicle. However, I haven't actually checked on the latest Spyder/Ryker models manuals, but I'd be surprised if that warning is not still in there, it was an Internationally Agreed and mandated warning for quite some time, and I doubt that's changed! :lecturef_smilie:
I understand what you are saying, and i know the bikes should not be run too low. But of the 6 spyders that I have owned, this gas gauge is definilty the most inaccurate. On all the other bikes, if they are run until the gas light comes on, they will hold right at 6 gallons (that is for the 2 F3T and the 1 F3L that I have owned with the 7 gallon tank.) The similar experiece was had with my 2014 RT. One gallon left when the light comes on. But this 2021 RTL is just different.