While the GTS-1000A is a magnificent bike, it does have little idiosyncrasies that pose challenges. Not the least of which is the fuel tank, most notably the flapper in the filler neck. As most who've ever fueled a GTS knows, it can take up to a dozen "burps" to get the tank full. This is due to the constrictive neck and flap keeping the air from escaping to allow more gasoline into it.
Okay, we all know why it's there in the first place- To keep people from putting leaded gasoline into it. Since the GTS has a catalytic converter, it's not very tolerant of lead. But realistically, how many gas pumps have leaded gas anymore? None that I'm aware of. So since this thing isn't really useful, and it only gets in the way, let's get it out of the tank and make fill-ups faster and more complete. It's not hard, and it's not really all that time-consuming. Start this project when you have under a gallon of gas in the tank, and you have an empty gas can handy.
The first thing to do is to remove the top and side bodywork to allow us to access the tank. Then remove the lines connected to the tank, and the wires connecting the fuel pump and gas gauge sending unit. Don't turn the key on before you disconnect the wires! If you do, the fuel pump will spray gasoline everywhere. How do I know this? I stupidly turned on the key for a moment to see what the level in the tank was, and both Dave Biasotti (without whom these modifications would not have been nearly as fast and easy) and I got sprayed.
Once everything's disconnected from the tank, remove the tank itself. This might be easier said than done- The two long flange bolts at the front of the tank tend to strip their threads. One of mine did. and I had to cut it in half with a dremel to get it out. Many hardware stores may carry this exact bolt, so you don't have to get it from Yamaha. Fortunately it's the bolt that self-destructs, and not the threads in the nuts welded to the frame. Just in case, I ran a thread tap through the nuts to make sure their threads weren't damaged.
After the tank's out, remove the fuel pump and the fuel level sending unit. Be careful not to bend either of the units, and don't damage the rubber gaskets- You'll need those again when reassembling.
Once the bag is in place, it's time to cut the neck out. Use a Dremel tool, preferably one with a flexible drive line. This moves the cutting bit far away from the motor, allowing a lot more control over the cutting, and it lets you get into much tighter areas for cutting. If you haven't got a Dremel, get one. Don't put it off- It's a remarkably useful tool for cutting, shaping, sanding, and polishing. It's one of the most useful tools I own.
Remove the bag from the tank without spilling the filings. If you did it right, you'll have no filings in the tank! However, if you did it like I did, you'll have a big mess to clean up inside. I shook out as many filings as I
As you see from the photo, the bag DID catch a lot of metal filings, even though I didn't tape it as well as I could have.
Now for the fuel gauge sending unit. I was lucky- the sharp edge of the bracket had only cut through the shield, not the wire's insulation. But I thought it'd be a good idea to make sure the problem doesn't get any worse.
If your insulation is chafed to the point of exposing the wires, I'd definitely suggest you use heat-shrink tubing, or even replace the wires entirely. Even if you replace the wires, I'd still recommend putting heat-shrink tubing over them as an added precaution against wear. This may be a bit of overkill, but I'd rather do that than risk having to go in to fix it again. (well, I do anyway, but YOU don't!)
Now it's time to reassemble everything. Mount the fuel gauge sending unit and fuel pump back into the tank. No sealant is needed for the rubber gaskets. Make sure that the mating surfaces are clean, so the gaskets will seal. When mounting the fuel pump and sender flanges - tighten in a cross pattern like any flange union so as not to warp it and once tightened this way, go around and tighten a second round. Don't torque the little bolts down hard- You don't want to crush the rubber seals.
Remount the tank assembly onto the frame, taking care not to strip the threads on the mounting bolts. By the way, the long (top bolts) are only 10 mm and don't need much torque as they are only holding the tank front to rear. You may have to loosen the 'U' bar brace in front of the tank to get the holes to align. Reconnect all hoses and wires. Pour your saved gasoline back into the tank, and then turn the key on. This will charge the fuel line with gas, and any leaks will be noticed immediately. If it's clean and tight, go ahead and replace the bodywork, and you're done!
Go to a gas station and fill the bike. You'll be amazed how much easier and faster it is to get a full tank. I mean, REALLY full. Unless you're used to spending the time and effort to burp all the air out of the tank, you'll get about another half gallon into it. Dave tells me that filling the bike on its centerstand will allow a bit more gas in than if you fill it on the sidestand.
It's been a few months since I'd done the above operations. And all that time,
there's been a little nagging voice in my head saying "You know, you really do
need to check out that electrical tape and see if it's a problem."
Seeing as how I always feel better when I pay attention to those nagging voices
(if only to shut them up), I broke out the tools again and pulled the GTS apart.
It's been a few months since I'd done the above operations. And all that time, there's been a little nagging voice in my head saying "You know, you really do need to check out that electrical tape and see if it's a problem."
Seeing as how I always feel better when I pay attention to those nagging voices (if only to shut them up), I broke out the tools again and pulled the GTS apart.
The plan was to remove the tape and cover the wires with heat-shrink tubing. It's durable, impervious to gasoline (as far as I know), and cannot unravel. I thought about replacing the wires entirely, but decided against that for two reasons. First, they'd be fine as they were. Since the tape without any stickum still protected them, and the bracket had been smoothed, I didn't see any risk of further damage. Second, it's possible that the wire I'd use to replace it would be of different resistance than the original. It may not be likely, nor might it be significant, but why risk it?
I re-soldered the wires back in place, mounted the sending unit back into the tank, and buttoned up all of the bodywork.
Note that I did all this with a very empty tank. I didn't feel like taking the tank back out again. I suspect that having a tank less than half-full would be fine, but I figured that the smaller amount of gas there was, the less chance I'd pull it out when removing the sending unit. I'd prefer to not spill gas on the bike.
So there you have it. Three months after the first operation, the tape was replaced. We've learned that gasoline really will degrade electrical tape, and probably in a short amount of time- My GTS has been sitting in my garage with an (almost) empty tank for a month. I can't say how long it took for the gas to eat away at the tape's adhesive, but it probably didn't take long at all.