Larger Gas Tank?

[Anonymous]

Hello, all!

I have a 1982 GS850GLZ. I love it a ton, but I can only get 100 miles or so on the highway before the gas needle is resting on empty.

Are there any larger tanks out there I can swap out that have the same mounts? What about an 1100? I'd prefer not to have a radically different tank style, but beggars can't be choosers.

Also, is there a way to increase gas mileage?

[gsBert]

i don't know if an 110 tank will have the same mounts, maybe someone else can help, or go to a scrapyard and see.

as far as increasing mileage, here's a few tips:

fuel consumption (if the carbs are right) is mostly rider governed

accelerating uses the most fuel, anticipate traffic so you don't have to slow down and re-accelerate a lot.

when leaving a light, i'll often skip second and 4th gear and just accelerate at a leisurly pace instead of gunning it.

tire pressure is critical, under inflated tires will really mess with your consumption.

loose weight (you and the bike)

remove all the anti-aerodynamic stuff (side/top cases, etc...)

make sure your brakes aren't dragging and your clutch isnt slipping

you can also change your final drive ratio by getting a smaller rear sprocket.

[Anonymous]

Hmmm...what is the proper PSI for the front and rear tires for my bike?

[gsBert]

depends on your tyres, radials take higher pressure than biais ply.
should be written under your seat.
i run radials on my bikes, and usually set them at 37 rear 35 front

[jimcor]

you can also change your final drive ratio by getting a smaller rear sprocket.

I reckon Thunderchicken and the 850GL can skip that one, huh!

[Steve]

Gsbert,

How is it possible to put a smaller sprocket on a shaft-drive bike? And how do you get away with running radials on narrow rims that were not designed for them?






Erik,

My wife rides the same bike, 82 GS850GLZ. Yesterday we went for a ride with a small group. Partly because of the group and partly because of the holiday weekend, we stayed at the speed limit, and we were pretty much on back country roads. Her bike has a Slipstreamer 2 windshield, leather saddle bags, luggage rack with sissy bar (all the anti-aerodynamic stuff). At the end of the ride, the trip meter showed 125 miles, and the gas gauge is just about at the bottom of the white line. Last time I filled the tank, the gauge was about the same place and I put in 2.7 gallons. That figures out to about 46 mpg. By the way, pressures in the new tires were 30/30.

While doing some other work on the bike, I played with the gas level in the tank to find capacity and to see where reserve came in. I found that the tank holds 4.1 gallons, reserve is exactly 1.1 gallon, and the needle is right on the big red E when it goes on reserve. This would mean that, at 100 miles and sitting on the E, you are getting about 33-35 mpg. Could be a LOT better.

As suggested by gsbert, try a more modest riding style and keep the speed down a bit. If your mileage improves to 40+, then everything is probably OK. In other words, if you drive it like a car, you will get better mileage. If you drive it like a motorcycle, you will have more fun, but won't go as far per tank. Just something you will have to live with.

Before you go to the trouble of taking the carbs apart to clean or change parts, run a bottle of Techron carb/fuel injector cleaner through them. It will be an over-concentration, but add the whole bottle, fill the tank, then ride it all out and refill the tank. This has worked wonders for others, no guarantee what it will do for you.

And remember, this is just my opinion, to which you are certainly entitled.

[Anonymous]

Steve,

You are very, very helpful, which is appreciated because I am a motorcycle newbie! I don't think I've ever had to use the reserve tank before. How do I know if I am using the reserve? Do I wait for the cycle to die and then switch the petcock over to reserve?

Unfortunately, after 100 miles interstate at 70mph, I was adding 3.4 gallons. BAD mileage for a bike that should get 40! Then again, I was doing some serious revving at some points....

I'll do the Carb cleaner thing you mentioned. Thanks a lot!

[Steve]

The reserve portion of the tank is enabled by moving the little lever on the petcock under the left side of the tank. The normal position of the lever is DOWN. If you need to get to the reserve portion, move the lever FORWARD. The BACK position is for PRIME, to fill the carbs before the engine runs. That should only be necessary if you have drained them for some reason. If the bike has been sitting long enough so that the gas in the carb bowls has evaporated enough to require priming to fill them, you might have other problems as well.

I know for a fact that the normal position is vacuum controlled. That is, it will be closed until the engine is running and providing a vacuum signal to turn on the petcock. I am under the impression that the reserve position is also vacuum controlled, but I am not sure. The prime position bypasses the vacuum valve, so it would not be a good idea to leave it there, just in case one of the carbs happens to overflow.

Try moving your petcock before you start the bike. How difficult is it? There should be a fair amount of resistance, but smooth. Go for a ride, get everything warm, at least 20 miles or so. Try to move the petcock again. Is it any more difficult? Take that into consideration on whether you want to wait until you use all of the main portion of the tank before switching. If you catch the symptoms quickly, you might be able to do it on the road without losing much speed, but chances are, you might end up on the side of the road while changing it.

Another thing to consider...the reserve part of the tank is there because the petcock's normal position draws through a tube that sticks several inches into the bottom of the tank. The reserve draws off the bottom. If, by some chance, the normal pick-up tube has come loose, you may be drawing off the bottom of the tank anyway, and you won't have ANY reserve! Two ways to check this: 1) (it's dangerous) take along a gallon can of gas, run the main tank dry. Switch to reserve. If you do have a reserve, all is well. If you don't have a reserve...that's why you brought extra. 2) find a container you can drain the gas tank into. Connect a hose from the petcock output to your drain container. Supply a bit of vacuum to the vacuum port of the petcock. Gas will flow into your container. When it stops, move the lever to reserve and try again. This would be a good time to measure how much you have in reserve, so you can guess how long you can ride before you will be pushing.

[dpep]

I strongly suggest that everyone test their reserve periodically to make sure they have one. Crud settles in the bottom of the tank and closer to the bottom of the tank is where the reserve intakes are. They can get clogged.

I bought a motorcycle a couple of years ago and was riding it home cross country when I discovered in the fast lane of an Interstate that I was out of gas and had no functioning reserve. It's no fun having to sputter, weave and pray yourself across three lanes of high speed.

If you never use your reserve, you don't know if you have it. You don't want to find out in the middle of traffic or stranded in the boonies somewhere. Just let someone know what you are doing and ride off with a near empty tank and a cell phone.

[gsBert]

oops steve: i did not know his bike was a shaft drive.... very good point though. next time ill look at the gallery for the type of bike before posting something stupid like the sprocket thing....

on the radial tire thing, stop worrying about my sanity, i have 4.5" rims on my bike (designed for radials) i know my rear is a 170 and my front im not sure about right now and the garage is 10 floors down.whatever was stock on a 1989 or '92 gsxr1100) so if he has biais ply, he should run lower pressures, but at LEAST what it says on his sticker, right?

thunderchicken: (i really like your name by the way, have you ever owned a firebird?) the 2 biggest factors are your riding style and your tire pressure, your life expectancy and fuel consumption depend on them both...
and learn how to put your petcock on reserve while riding, i got stuck in the left lane while runnign dry, and the !@#@# wouldn't budge, it's a huge safety hazard when you have no shoulder to pull up on...

[Anonymous]

[quote="gsBert"]oops steve: i did not know his bike was a shaft drive.... very good point though. next time ill look at the gallery for the type of bike before posting something stupid like the sprocket thing....

for future reference, gsBert, all 850's, regardless of year or whether a regular model or "L", are shaft driven.

no exceptions.

[Steve]

GSBert,

Thanks for the info on the radial tires. It is nice to know that you at least did it properly. I have talked to a few people that have tried to put them on the standard rims, and it will not work that way. Radials (on bikes) need to have much wider rims for stability, and it appears that you have made that change.


1100GK,

I was not aware that ALL 850s were shaft-driven. I was going on the fact that he mentioned a G after the 850. I guess that means that there were no 850L models, only 850GL and 850G models?

[kalessin]

FYI, the GS850GL and GS1100GL models have the same gas tank.

The tank mounts for the larger (by a gallon) GS850G gas tanks are in a different place, and the G seat is a different design and has different mounts. Changing tanks would mean making adapters for the rear of the tank and altering the seat, etc.

[Anonymous]

steve, you are correct.

all 850's are 850g's.

a 1980 "L" model would be correctly termed a "gs850glt", and a regular model would be a gs850gt.

"t" is for 1980. "x" for 81, "z" for 82, "d" for 83, "e" for 84, and "n" for 79.

why suzuki chose those letters for those years, i'll never know...