As far as the fuel sensor, replace the sensor/petcock for $45...
Nope; pretty sure my sensor still works (as it was designed to, which is sucky). If I did want this poorly designed system to function better, I'd probably add a small foam float under the sensor's float (which works on a reed switch, I'd guess, not a hall-effect switch) to delay the closing of the switch to a more useable 15-20 mile reserve.
Just to be extra clear: IMNSHO, in this case, a totally functional low-fuel warning system that is working correctly, as designed, is next to worthless. Way-way-way too much fuel left in the tank.
Bone throw: I suppose, John, if I was getting 50mpg like you (I'm assuming you have the stock tank, which I measured on my '14 and it holds 2.111 gals) AND the LED did not come on until I'd gone 80 miles, the 25 mile reserve (IOW, 0.5gals) would be acceptable, maybe liveable (still a tensy high for my tastes). But my experience,
and measurements, have been much different.
I think our 310's are pretty close too (same mods, including ZTR ECU work... 'cept I have a TI Leo Vince pipe) Note: I run 12z-51z sprockets, using a GT fatty on the front & a Mountain Hybrid on the rear... both of these tires are pretty much the heaviest in their classes (and frikken fantastic, 'specially that fatty)
...As far as the crossover, I figure better to leave it on and equalize levels. Otherwise I would assume with bumps and varied lean angles you may get air into the system or just starve at times till some fuel splashes over, but on a long carve to the right you may starve the system as opposed to fuel quickly leveling directly where the pickup is on the left. As far as fuel line issues, only one I can think of is the possibility of the left petcock hitting the water pump if the tank is not spaced. I get roughly 45 mpg as well and fuel light comes on about 75-80 miles with a .5 gal reserve.
[the following reads a bit harsher than I intend:] well, you figure wrong; and your assumptions are wrong. I suppose if you raced the british short track circuit (not a real thing, AFAIK), that long-right-turn might affect you. maybe. (OTOH, if you think it through, the same situation with the petcocks ON might cause starvation too; fuel goes all to the right side).
But my experience shows me the difference is barely
measurable: call it 1.6 miles of travel (after which, I get to go a bit farther- minor win) and no negative effects. With your style of riding, that might be as high as 10-12 miles (major win).
John (and Alberto?)- don't assume, do the experiment and make the measurements- you're gonna be surprised, I bet.
[Johnrg- I just thought of something: if you haven't measured how much fuel is left (your .5 gal statement) when the light comes on, as opposed to calculating it based on a possible erroneous 2.25gal tank specification- you might wanna do it, just so you know what you're dealing with. It does jive with the tech spec that say reserve is 2.43qts. I'd like to know the volume of other 310r tanks, too. OTOH, if you do know this... good. I don't wanna be snarky]
BTW, when these bikes run out of fuel, there is very little stumbling... they just die. I've done it on purpose a handful of times. And I think fuel injection pump systems habitually take in air; which is why most have the recirculation design- constant air-free fuel pressure. Do our bikes recirculate at the fuel regulator? -because I dunno. But don't worry about getting air into the system... either it isn't a big effect or it ain't happening.
And as far as a crossover line failing, I will admit that it is not a frequent occurrence. It has happened to me- but on my harley (my "shovelhead"). However, it does not take much imagination to figure a scenario where a branch rips it off, or tangling with another bike in a fall which can pull it off. So another win, albeit minor.
To recap: with the petcocks
closed, you get a minor or moderate reserve (depending) and insurance against a crossover fuel line failure. And your low-fuel LED still works and functions the same. But with the petcocks
open, and your fuel level is "equalized", does that mean you can't suck in air? No, not all- but it does mean when you're out of gas- you are OUT.
BTW, I don't know of too many dirt bikes with crossover lines on their stock tanks. This tank is not that deep or asymmetrical- so I'm fairly convinced they don't need it.
And it use to be standard practice to lay an "empty" bike down on it's left side to get that last 7 ounces of fuel over to the other side, 'specially on MX'ers with no reserve on the tap. No more? sheesh, I really am getting old. It used to be 2nd nature to reach down and turn the petcock to "on" during the first 50 feet after taking off (this to insure you're not on "reserve" or "off") but no more, I guess. Actually, (kinda funny) Chad Reed's mechanic got so frustrated with Chad habitually doing this (and accidentally turning it off- race bikes can have weird petcocks and just about never have a reserve) so he broke the lever off. Can't turn it without a pair of pliers now. Hah- I have the same disease... since 1968; so there's no cure I guess.
Also, I did read your thread when you wrote it, again when I got my 310r last year, and just now. Good info- thanx.
The way the valves work is basically to allow the flow from one tank to another. In the bottom of each half of the tank, there is a valve(petcock) the right side of the bike is the traditional petcock(with handle), which has the low fuel sensor, the left side of the bike, is basically a valve. Both are connected thru a little black hose that travels over the cylinder head. If you have your tank filled up, it will allow fuel to circulate to both sides, and keeping them at about the same level. You should have both always open for better functioning.
uh, yeah Alberto- I am pretty sure everybody understands what this simple system is doing. It turns out, in real life, the crossover system is unneeded. And it does absolutely nothing for a full tank- only when the fuel level is lower than the frame. Also, you guys did read the part where I said this was a new account for a 5 year member; and that I am "shovelhead85", who posted a year ago on this thread, right?
one mo': when you do run out of fuel, using either system of closed or open petcocks, close at least ONE of 'em if you are transferring small amounts of gas (like, say, from another bike) to make sure it all stays on the left side- to get maximum range. Hell, drain the crossover hose into the tank to get an extra 200 yards.
Hope I didn't ruffle any feathers... but measure your performance & capacities; you might find it's best to keep those petcocks closed. I'll try to keep an open mind if someone comes up with a good reason to ride with 'em any other way.
). Also, it takes quite a bit of time for any remaining gas to transfer- grrrrrr. My "dry" gas tank then held 2.111 gallons and 2.100 gallons upon refilling, so I'm guessing the fuel volume was not calculated taking the internal pump & filters into account.
