82 Suzuki GS450L Dumbest fuel problem ever

[Ishamael]

Well I just had the dumbest thing happen.

My bike won't have plates on it till next week, so I went to the gas station and filled up the can. The can is one of those kinds with the spring loaded plastic filler funnel, where you have to push on it to open up the end.

As I was filling the tank, the spring popped and sent half the filler tube and the o-rings flying into the gas tank! I didn't notice at first (I thought that just the spring had popped, which I grabbed before it went in), and tried to start it. When it didn't start, I looked at my can and realized pieces were missing.

I had to take the tank off, pour out all the gas (there was a lot of sediment in the gas), fish out all the pieces, put the tank back on, and pour the gas back in through a filter to make sure none of the sediment went back in with it.

SO DUMB!

Anyhow, now it won't start. Obviously it's a fuel problem, but I'm not sure where to begin. My first thought would be a clogged filter or line maybe, then maybe a stuck carb. But I'm not even getting a rough idle, it's just trying to start and nothing's happening combustion wise. I know I got all the pieces out

Any ideas?

[ccratin]

Make sure you reattached the lines correctly, especially the vacuum line going to the petcock. Try it on prime instead of ON. You may need to put it on prime the first time anyway in case there's some kind of vapor lock going on. Make sure that your plugs aren't fouled and that you are getting spark.

[Ishamael]

Yeah, I'm sure they're back on right. I only disconnected 2 lines to take the tank off, the vacuum and the fuel line, and they won't fit on each other's fittings, so I'm sure they're back on correctly.

Here's a quick question for you, while I'm thinking of it.

If I disconnect the fuel line from the petcock when the petcock is in the "ON" position, should fuel drain out of that line? (it currently doesn't).

[RichardW]

I wouls say it shouldn't drain because there is no vacuum present on the vacuum line.

[Ishamael]

I wouls say it shouldn't drain because there is no vacuum present on the vacuum line.

OK, well that answers that. I figured that if it was supposed to drain and didn't, that would mean the clog was definitely in the tank or petcock.

[ccratin]

It will only drain on prime if it's functioning correctly. Otherwise, the engine has to be running to produce the vacuum for the petcock diaprhagm to open and allow fuel to flow.

[IanFrancisco]

You didn't mention which bike you have. My GS450S has a petcock with a larger diaphragm and no PRI position. I had to search hi and lo to find a replacement. (Old Bike Barn has them.) In ON or RES on my petcock there must be vacuum present or no fuel flows. There is a screw to loosen to drain the tank but when it's loose it drips as much gas on the ground as it does out the pipe and would take hours to drain a full tank. I have been working on my petcock lately and when I re-install the tank I usually bite the bullet and apply suction by mouth to the vacuum line to open the petcock and fill the carbs. It's also a good (!?!) way to tell if the petcock diaphragm is leaking...

[coconutcolin]

wow.

[jonr]

You indicated a lot of sediment came out. I would think that either the petcock screen or fuel filter was clogged.

J

[Ishamael]

wow.

While not a very helpful post, this pretty much sums up my feelings as well.

Thanks to everyone else with the ideas, I'm going to give it a whirl this weekend and I'll keep you updated.

[Guest]

I had the same problem with the second GS450 I brought back from the dead. First, the petcock may have some crap in it clogging the openning. Fuel SHOULD run out once the fuel line is disconnected from the bottom of the tank. (I have personal expierience with that!) I would pull it out and give it a good cleaning. The second and dumbest thing is how much fuel is in the tank. If you only have a gallon or so in the tank you may have to tilt it to get it near the petcock. (I had this happen too.) The bike ran like crap until I filled the tank and gave it some fuel to run on. I hope this helps. I have all 3 shop manuals for this bike so let me know if there is any info I can look up for you.

[Ishamael]

I have all 3 shop manuals for this bike so let me know if there is any info I can look up for you.

Thanks, snark.

Here's what I did today:

I took the hose off the petcock and turned it to PRIME. Nothing happened.

A-ha! I thought, it's a clog in the petcock!

I took off the tank, disassembled the petcock, cleaned it, and reassembled it. Turned it to PRIME - Voila! Fuel! It poured out like a beautiful stinky river.

I reconnected everything, and...

still no start!! I've got 5 gallons of gas in there, I know gas is flowing out of the tank. Which means there's a fuel problem further down the line, but unfortunately I'm out of weekend and will have to wait till next week to figure out the mystery.

I'll keep you updated...

[blo]

My -81 GS450ex has a screen filter on the needle valve seat. This is the screw-in type needle valve seat, not the pop-in type. If gunk has come into your fuel system, it may as well have clogged up this filter to.

[Ishamael]

My -81 GS450ex has a screen filter on the needle valve seat. This is the screw-in type needle valve seat, not the pop-in type. If gunk has come into your fuel system, it may as well have clogged up this filter to.

Do I have to take the carbs all the way off to get at that, or is there another way?

[Tighthead]

Yeah, you do have to take off the carbs to get to that little screen. And getting the carbs on and off my 81 450L is a PITA.

Since it's easy, I would take a look at your plugs. Just ground the plug against your engine block and look at the spark. If there's not much there, change the plugs.

Then make sure your battery is strong.

I would do that before you try to pull off the carbs.

Good luck to you.