won't start - bad gas?

[i2kdave]

Yesterday, I rode about 35 miles, got gas, rode another mile or so to someone's house, hung around for about 30 minutes, then rode about a half mile down the road and my bike shut off at a stop sign and wouldn't start back up. The engine would turn over, it just wouldn't fire off. After tinkering with it for a few minutes, I finally got it to start back up by giving it full throttle while starting and I got about 5 more miles down the road before it shut off again, and it hasn't started since. The spark plug is firing, I know that much, and I'm suspecting I got some bad gas. Before I try anything else, I want to try draining all the gas out and replacing it, but I can't find anything in the service manual on how to do this. Anyone got any tips? Thanks!

[JWR]

Pull the fuel line off and turn the fuel lever to prime , or you could remove the tank.

Taking the tank off would be much faster.

Remove the seat... two bolts....pick up on back of tank and pull back.

[Water Warrior 2]

Originally Posted by JWR

Pull the fuel line off and turn the fuel lever to prime , or you could remove the tank.

Taking the tank off would be much faster.

Remove the seat... two bolts....pick up on back of tank and pull back.

If you remove the tank the fuel lever should not be in prime position. And be sure to unfasten the hoses from the back of the fuel cock(lever). There are 2 of them, one for fuel to the carb and the other is a vacumn line from the engine. Now would be a great time to install an inline fuel filter for a couple bucks. And a little gas line cleaner to help rid the stuff mucking up the carb etc.

[Easy Rider]

Originally Posted by JWR

Pull the fuel line off and turn the fuel lever to prime ,

+1

And be sure to drain the carb bowl too. That is done with the brass screw at the bottom......right next to the drain nipple.

Then use PRIme again for a minute or two before trying to start with the fresh gas.........or you can put it on PRIme and crack the bowl drain screw to be sure you are getting the fresh gas into the carb.

[Water Warrior 2]

Excellant idea, why didn't I think of that ? Oh here's one now. For future tank fill ups, if you see a fuel tanker off loading at the station don't go there. Try the next gas station instead. When the tankers off load fuel they stir up all the sediment in the underground tanks and you get very dirty gas. Or wait 24 hours.

[mrlmd1]

Let's start off the discussion with what you mean by "bad gas"?
Sediment?, water in it?, old, where all the volatile explosive vapors have evaporated?
Gas can last a year and still be OK if there's no water in it, sediment could clog filters or carb jets, so just emptying out a gas tank and starting over may not be the solution to your problem, but it's an OK place to start looking if you suspect that.
Just my comment that if you had "bad gas" it would be unlikely to run fine, then suddenly stop, then run OK again, then suddenly stop again. When it was running, was it smooth as usual, or rough, missing, backfiring, anything unusual? Lousy gas usually makes an engine run lousy.
You may have some other problem,like an intermittent electrical disconnect, short, something else. Even a faulty side stand switch or other cutoff.
How did you check the spark plug firing? Did you remove it and look at the spark? If changing the gas and trying to clean the carb doesn't work, look for some electrical problem.

[i2kdave]

Thanks for the tips! I haven't gotten around to messing with it yet, I have to find something to drain the gas into.

what you mean by "bad gas"?

I'm not sure, I just know my bike screwed up shortly after I filled up. lol It just seemed strange that it worked fine for 35 miles and then gave me problems right after putting gas in it. Could definitely be something else, but that was my first guess.

When it was running, was it smooth as usual, or rough, missing, backfiring, anything unusual?

It seemed to run normal for a few miles, then as I was approaching my dad's driveway, it finally cut off again as I was pressing in the clutch to downshift.

How did you check the spark plug firing? Did you remove it and look at the spark?

Yes, I took the plug out and held it against the engine while pressing the starter.

[i2kdave]

Still haven't had a chance to drain the fuel, but here's an update:
Tried starting it last night and it fired right up, ran for about 1 minute (although it seemed like the choke didn't have as much effect as usual) and then just shut off!

[mrlmd1]

If it just plain out quit all of a sudden instead of running rough and sputtering first, this sounds more like an electrical problem rather than "bad gas". Before you go and screw with emptying the tank, check out all the cutoff switches, like on the sidestand for instance. Or it could be the gas is not flowing altho this is unlikely if it just instantly stopped. To check this, put the fuel valve (petcock) on prime, remove the drain on the bottom of the carb and see if fuel flows readily and see what's in it if anything, ie., water or sediment. You do have the petcock set to the RUN position, right? Make sure you have no vacuum leak from the hose that goes to the petcock to open the fuel supply when it's running. You might try running it on PRIME and see if it quits, or on RESERVE. Possibly the screen over the RUN position intake tube is clogged.
I still think this is something other than bad gas. Even a dirty carb or something plugging it up. You could try putting some Berrymans in the tank at the recommended dosage and see what happens.
So many other possibilities, try eliminating them first before taking off the tank.

[Easy Rider]

Originally Posted by mrlmd1

You might try running it on PRIME and see if it quits, or on RESERVE. Possibly the screen over the RUN position intake tube is clogged.

:plus1:

And if it runs OK on PRIme, there might be a problem with the vacume operation of the petcock when in the RUN and RES positions......like a loose or cracked vacume hose......or defective petcock.