No Power!

[spydah]

I'm trying to get my sisters 92 GS 500 ready for the season, but its got no power at all and doesn't seem to want to run. I changed the plugs, swaped the oil, inspected the air filter. I found that the fuel lines had cracks, so I replaced most of the fuel lines. Didn't make a bit of diference.

I'm thinking its something with the carbs. Anyone got any ideas? I noticed something strange when I was replacing the lines. The inlet to the carbs has some sort of plate or something that does not move when I twist the throttle. Is that normal?

The plate i'm talking about is the sideways apple logo shaped plate you see in the inlet in the picture (from the manual) below.

[spydah]

Ok, I found a GS500 forum and it sounds like your dead on. It seems the Petcock is notorious for going bad, and its vacuum operated. I'm going to try to bypass it and block off the vacuume line from the carb.

Thanks for the help!

[Kurlon]

I just went through the re-plumbing process, before you bother, you can test your carbs to verify the vacuum slides are working. If you look at the bottom of the carb openings, there are two holes, one of these supplies air to the top of the carb, which causes the slide to climb. Get an air nozzle and blow some air into those ports, if you don't see the silde moving on either one, you've likely got a torn diaphram.

[DuncanMoto]

If this bike was stored without stabil it may have so much varnish in the carb bowls and jets that you'll need to rebuild them.

[BostonSVkid]

So if you replaced all the fuel lines then you just may have to replaced the carb lines as well. Typicall all those lines are made of the same material.

[spydah]

I just went through the re-plumbing process, before you bother, you can test your carbs to verify the vacuum slides are working. If you look at the bottom of the carb openings, there are two holes, one of these supplies air to the top of the carb, which causes the slide to climb. Get an air nozzle and blow some air into those ports, if you don't see the silde moving on either one, you've likely got a torn diaphram.

Cool trick! Thanks! I'll try that.

[stoinkythepig]

I just went through the re-plumbing process, before you bother, you can test your carbs to verify the vacuum slides are working. If you look at the bottom of the carb openings, there are two holes, one of these supplies air to the top of the carb, which causes the slide to climb. Get an air nozzle and blow some air into those ports, if you don't see the silde moving on either one, you've likely got a torn diaphram.

You can use a shop vac on the carb inlet to test the slide operation, if you don't have compressed air. Be damn sure the fuel bowls are empty though.

[The Snowman]

If you used "Stabil" when you put the bike to sleep for the Winter. I have been hearing that Stabil" isn't working well now, due to the 10% of alcohol which is in our fuel now.

Hey wait a minute, I ran my CBR on Stabil for almost the entire fall and winter in 06-07, remember? every time I put the bike up with Stabil, it got warm out and we all rode.

[The Snowman]

Right, but it ran on Stabil all that time. I also use techron once in a while. You definitely notice a little difference when you do.

[Kurlon]

Chuck,

I am only repeating what my dealer has been saying. They have people coming in with bikes that won't run & they have been using Stabil.

They are tellling me that "Techron" is the thing to use.

I never use Stabil, my bike is always going out at least 3-4 times a week.

P.S. Your bike didn't sit all winter with Stabil in it, you rode it last Winter as it was so warm out.

Weird, my ST3 sat all winter after being Stabilized, and it fired right up last week, no drama, first hit after priming the fuel rail (turned the bike on and off 3 times, giving the fuel pump a chance to prime each time).

So far not a single bike coming out of storage has had fuel related issues after being Stabilized for the winter.

Techron is a cleaner, it's essentially 'rocket fuel' that does nothing to stabilize the gas it's in, I wouldn't count on it keeping your fuel system from varnishing over the winter or the fuel from going bad. All it'll do is help rip that mess up once you do try to fire the bike back up, assuming it will start.