I’m doing this page for the benefit of the noble webmaster of the YZF-R1 Forum, since every time we ride together, he is forever panicking because he thinks he’s running out of fuel, even though I know he’s not. This one’s for you Willie.
Anyone with a '98 R1 knows that the low fuel warning light comes on ridiculously early. Yamaha knows it too, because they changed the sensor in '99 to come on later. Being the tinkerer (cheapskate) that I am, I wasn't going to spring for whatever absurd price Yamaha must want for that little jewel to replace my '98 sensor with a '99 sensor, so instead, I fixed mine. My low fuel light now comes on with EXACTLY 1 gallon of gas left in the tank. The tank’s total capacity is 4.7 gallons. Sorry for the fuzzy pics, but I think you'll get the idea. I didn't have a pic of an un-modified stocker either, but I think you'll STILL get the idea.
The low fuel sensor bolts into the bottom of the tank with two phillip screws. It's obviously best if you remove the sensor when you're almost out of gas...which is about sixty-five miles after your low fuel light comes on. ;-} Removing the tank is necesary to keep fuel from spilling everywhere. The low fuel sensor will be the only thing you see attached to the bottom of the tank with wires coming off of it. I won’t go into the details of removing the tank, because if you can’t do it on your own, you probably ought to have someone else perform this mod anyway.
In the picture above, you're looking at my modified low fuel warning sender. The two big brass tabs sticking out near the top of the sensor stalk with the small bead of solder evident (near the loop in the wire) is where the sensing bulb was originally installed on the stalk. I de-soldered the sensing bulb from the stalk and re-soldered it back lower on the stalk.
Here you see how I soldered the bulb back onto the stalk. The small black dot you see is a plastic retainer that holds the sensor wire to the stalk. You can use this retainer as a reference point for relocating the sensing bulb.
Here is a different view of the sensing bulb. You can see the black plastic wire retainer with the sensing bulb approximately 1mm above it. Note: You should carefully remove the black plastic retainer before doing any soldering to avoid melting it. My low fuel light now comes on with exactly one gallon left in the tank EVERY TIME!! I did this mod four years ago, so there doesn’t appear to be any reliability issues with the modification.
Disclaimer: This worked very well for me, but since this is a do-it-yourselfer kind of thing, and I don’t know how good a do-it yourselfer you are, if you screw it up, it’s your baby and I can’t be responsible. If you’re unsure about the whole thing…don’t do it! If you’re pretty handy mechanically and want to try this, I hope it turns out as well for you as it did for me. I didn’t do anything special, I just exercised normal care and attention to detail. I know others have done this mod with similar results, so it’s definitely do-able, and I didn’t just get lucky. May the force be with you ;-}
