Fuel Gauge

Has anyone fitted a fuel gauge to a CB500, or knows if it is a possibility?

Not a gauge exactly, but you could put a 'T' piece on to the fuel tap outlet, and then run a length of clear fuel hose from it up the side of the tank. You'd be able to see the fuel level at a glance.

Ghetto engineering 

I was actually only thinking about this last night on the way home. I plan on doing a fair bit of touring after college on the 500 so it would be nice to know how much fuel I have in the tank. Neither the Gz125 or the CB250 have a fuel gauge fitted so I always just used the clocks to calculate how much I have left.

Id imagine you would need some sort of mechanical switch/sensor within the tank for a gauge to work ? Would probably be tricky enough to fit an aftermarket one.

Ride the bike for a while. You'll soon be able to tell to within 5 miles how much fuel you have left, which is much more accurate for real world use than an abstract needle which either points to the right or to the left with variations in between.

What Basil said.

Really. The odometer is all you need. And if you really want to stretch your range, add a small canister of petrol to your luggage.

I simply ride until I need to switch to reserve - then I start looking for petrol stations. The CB has a comparatively big range. And a proper luggage compartment. It's - utilitarian.

Caveat: Do remember to switch back to 'main'. And do remember to take into account that higher average speed (motorway) causes reduced range.

My experience of motorcycles fuel gauges suggests that (as mentioned by others) using the trip-meter to estimate the amount left is probably more accurate than most gauges.

You can also get a pretty good idea by loooking through the fuel filler in the top of the tank and sloshing it from side to side a little.

As a very rough guide: I get about 45 miles-per-gallon (1 litre to 10 miles or 16 km) from my bike, so a 17 litre fill-up (that is, from reserve to full) gets me about 170 miles until I have to switch to reserve.

If you were touring (rather than my short commute) I suspect you would get more than 45 mpg, so if you started to look for fuel at about 160-170 miles (250 - 270 km) then you would probably be fine.

The best way to find this out is to go for some day-long type rides, taking a small (1 litre) emergency fuel bottle with you and work out how many miles you get until you have to switch to reserve. You probably won't have to use the emergency fuel, but...

I agree with al the comments about the gauge accuracy-or lack of it, and I do generally try and fill up around the 150 mile mark regardless of the type of riding I've been doing, so tend not to get to reserve very often unless I've been caning it a lot, but I just fancied having one.

Llewelyn1965 wrote:I agree with al the comments about the gauge accuracy-or lack of it, and I do generally try and fill up around the 150 mile mark regardless of the type of riding I've been doing, so tend not to get to reserve very often unless I've been caning it a lot, but I just fancied having one.

I've never really looked into how fuel gauges are mounted in motorcycle tanks, but I suspect if you really wanted one it might be easier to mount the tank of another bike onto the CB500. Then you only have to do work to the outside of the tank to make it fit, rather than fiddling around inside the tank.

In fact, if you did this, but found a larger tank that fitted without too much work, then you would have made a useful improvement!

badseeds wrote:

I like the look of this. 2 questions. 1, what is this off, and 2, how would the gauge be given the info from the tank?

The picture originated on the Brasilian CB500 page. The gauges are completely homebrewed. A sender unit was retrofitted into the tank and a gauge grafted on.

If you're on Facebook, check out the group. These guys aren't afraid to pull their bikes apart and modify 'em.

I don't think it's possible TBA. You need to fit a sending unit inside the tank - which would probably have to be adapted from another bike. Most require a hole in the bottom of the tank, with everything needed to fix and seal the sender in place. 

Then you'll have to calibrate it to whatever gauge you get - however that is done. Might be a simple adjustment on the gauge or a whole load of electrical jiggery-pokery trying to reduce (or increase) the signal from the sender.

As most say -180 miles is the average you get before going on to reserve. So 90 odd miles is half a tank and so on.

It's very much possible. One of the Brasilian lads did it. They do amazing stuff with their bikes.

Possible for a group of guys who spend their lives modding stuff and probably have all the equipment to do it - and do it just for the heck of it. But it's a major job that has to be done right and will scare the life out of insurance companies, needing an engineers report. For such a small gain I can't see the point.

Insurance companies and engineering reports?  

These guys probably don't wear a hard-hat and hi-viz, either.........

My insurance company wasn't interested in any modifications that didn't affect performance. 
So long as the bike has an MOT & is roadworthy in the event of an accident claim they're happy.

Mine (Chaucer) weren't interested in the hot-grips, home-made hand-guards, Givi rack & box, Renntec crash bars, headlight/gauges protection bars, incorrect indicators or sticker-bombing. They just wanted my money. They all do.

badseeds wrote: They just wanted my money. They all do.

Amen to that. :)

that's insurance company's for you