Can only use half the tank?

[liv2wrshp]

I think that I have a 4.5 gallon tank, but i go dry at like 2.5 gallons used. Should my reserve be two gallons? Maybe a bad petcock? It's consistantly the same way. I only get to go around 100 miles. Kind of annoying.

[t3rmin]

I'm wondering the same thing. I ran out after 2.4 gal the other day and switched to reserve, but got only a trickle (as viewed through my clear inline filter). Yet when I had the tank off (albeit full) later, the petcock switched to reserve, and sucked on the vacuum line, gas streamed out nicely, just like it does on "run".

I figure if the reserve tube is plugged, it'd be plugged whether the tank was empty or full, right? So why a trickle when "empty" and a stream when full? Or when on the reserve setting does the petcock draw from both the "run" tube AND the reserve tube?

[liv2wrshp]

Yes, can anyone help us?

[jeeptrix]

Do you have a separate filter attached to your petcock inside the tank? My bike does. It has a very fine screen that could easily plug.

[liv2wrshp]

So if that's clogged, that could cause it act like this?

[t3rmin]

Well I need to take my tank apart to deal with some rust anyway (probably related) so I guess I'll find out when I do that.

[jpaul]

Try putting the petcock on prime. If it runs ok then, the screen on the filter in the tank is probably clogged up.

[earlfor]

Most likely, sediment has built up around the base of the petcock screen in the fuel tank. I would remove the petcock and clean the screen that attached to it.

Earl

[DIGHOUSE]

I don't think the question was answered.

The question, prior to the reserve debate was whether the tank should have a two gallon reserve. I have had the same question, I have a 5 gallon tank and need to go to reserve somewhere around 120/130 miles, usually around 3 gallons to fill up, 40 something MPG. I know my reserve position works good since I do use it occasionally when I run out of gas,, petrol for our friends in the UK. So is two gallon reserve correct?

[twistedwankel]

My 82 GS450 when I had to replace the petcock assy. There were two screens at two fixed levels in it. If you put it on reserve it would run continuously until you are out of gas completely full stream. Also if you put it on prime by accident you could easily flood the engine if the floats failed even a little.

My 81 GS750 definately has a 5 gallon (19liter) tank. 1.1 gallon (4liter) reserve. I virtually never get more than 3.8 gallons into it while sitting on kickstand at an angle. I almost always get 177miles to reserve and actually ran out while waiting my turn at pumps. It took 3.8 gallons reasonably full at a parked angle. That was really trying to top it off and not run over the paint as it comes up in the neck.

Hope that answers your question about the tank.

[Tom MLC]

Has the tank been kreemed? If someone did that with the petcock installed, the lower level of the screen may be obstructed.

[argonsagas]

Let's just summarize all of this.

No, you should not have a 2 gallon reserve. It should be about half that amount, although it may vary a little bit with each tank.



Yes, there is probably some obstruction in the screen.

You should remove the petcock to inspect, and then clean the screen.

Check the tank while you are doing that, as it sounds like you have a build-up of something in there.

If the screen is shot you can replace the petcock, or just remove the screen and run without it, but that means you MUST install an in-line fuel filter.

[mooks420n]

check the diaphram

I think that I have a 4.5 gallon tank, but i go dry at like 2.5 gallons used. Should my reserve be two gallons? Maybe a bad petcock? It's consistantly the same way. I only get to go around 100 miles. Kind of annoying.

If the diaphram does not move freely and the vacuum decreases it will block fuel,as i discovered a couple months ago,

The spring wings on my petcock's diaphram were busted,so I trimmed a small spring to preload it, I would run out gas at roughly half tank untill I trimmed the spring more so the diaphram would operate in lower vacuum.It worked untill my new petcock arrived.

[DIGHOUSE]

I did not mention that I have a 79 GS 1000, but as long as the reserve position works good I don't see any reason to pull anything out. If it aint broke don't fix it. It is said that the only sure thing is death and taxes. Well if you own a 79 SUZUKI you can be sure of something else, something is going to need fixing, and when it does the Missus is going to give you that look again. Y'all know the look!

[Steve]

the Missus is going to give you that look again. Y'all know the look!

The only time MY Missus gives me "that look", it's because it's HER GS850 that's down. She wants to RIDE. 8)


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