New/rebuild petcock vs. bigger used tank

[Guest]

The fuel tank on my 81 gs650gl seems small - about 3 gallons. It'll seem bigger with the better mileage my carb boots, carb o-rings, and valve adjustment, but it's still dinky.

I just found out the petcock is leaking small amounts (for now) of fuel into the vacuum line.
Rather than rebuild the petcock (unreliable results) or replacing it with a good-used/new one, what about replacing the tank with a heftier one?

Is there a tank interchange reference somewhere (maybe bikecliff's page) or does somebody know off the top of their head?


I'm strapped for cash right now, and wondering if plugging the vacuum line and using the petcock's prime setting as a manual on-off switch would work for a few weeks. Seems like it could be a very bad idea, or a creative workaround.

[Agemax]

forget the bigger tank, fix or replace the petcock.
probably work out cheaper than a larger tank and bodging a pet cock is just a recipe for disaster.

[WilliamGLX81]

Why? I'm still going to want a bigger tank. But that might wait until my "next" bike. Maybe something with twin disc ABS and fuel injection... heh.

Anyway, fantasy aside, I have seen multiple people say that the petcocks are often not repairable.

[Agemax]

so buy a new one then. bodge your old one by blocking off the vacuum pipe and running it on prime is not a good idea.

[Charlie G]

Willaiam,

L have small tanks. Get a new petcock or buy this.... http://humboldt.craigslist.org/mcy/3923757507.html

[WilliamGLX81]

Willaiam,

L have small tanks. Get a new petcock or buy this.... http://humboldt.craigslist.org/mcy/3923757507.html

GAH, that looks awesome! Other than the mileage... But yes. I keep wondering if this bike is worth so much work. I'd rather have something with fairings and powerful brakes.

Any reason I can't put a G tank on it?

[Big Rich]

From my experience, if you swap gas tanks you also have to swap seats and sometimes side covers as well. Larger tanks are usually larger in every direction (back towards the seat, etc.).

[Steve]

GAH, that looks awesome! Other than the mileage...

What's wrong with the mileage? My wife's bike has 66,922 showing on it, will probably turn over 67,000 on tomorrow's ride to lunch.

.

[WilliamGLX81]

Hmmmm. Well then. I thought that problems with the top end started to show up around 40,000.
This GS650 I have has "8,000" on it, but the speedo cable was smashed and rusted before I bought it, and it had been at least laid down once, at speed.

[Charlie G]

William,

I wouldn't worry about the mileage. The 850 is a pack mule and good for 100k plus miles. My 650 g needs a drink every 100 miles before reserve kicks in. I don't think a G tank is going to help you out. I saw you had your bike up for sale earlier this year. The coast is a slow market. It would have sold for what you were asking elsewhere.

cg

[Charlie G]

Hmmmm. Well then. I thought that problems with the top end started to show up around 40,000.
This GS650 I have has "8,000" on it, but the speedo cable was smashed and rusted before I bought it, and it had been at least laid down once, at speed.

I have 47k on mine and it's still the beatie it was a 30k. Physics Teacher posted last spring his has 90 plus on it. Don't discount what these machines can do.

[WilliamGLX81]

Sweeeet! It's good to know. I remembered reading something that said to look for problems in the old GS technical data, I wasn't just assuming. Maybe I'll be able to pick that one up after all.