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Virago won't fire

Posted: Sun Nov 26, 2006 6:43 pm
by black mariah
I just picked up an '81 Virago 750 for stupid low dollars. The starter button is apparently screwed up so we have to go across the contacts on the starter solenoid. When we do the motor turns smoothly, we have spark on the plugs, but it will not ignite. There is fresh fuel in the tank, so I know that's not a problem. I'm not sure what other information may be needed for you guys to give me some help, so I'll leave it at this! :mrgreen:

*EDIT*
Oh, BTW, YES the battery is charged. :laughing:

Posted: Sun Nov 26, 2006 6:47 pm
by Sev
Three things you need to get the engine going.

Compression, Fuel, and Spark.

You said that the spark and fuel are both good (though I'd look through the carbs VERY carefully on a bike that old I'd be very surprised if the carbs were clean) so do a compression test. If you're not getting compression that means a couple of things but most likely you'll either need to change out some gaskets, OR get new rings.

Posted: Sun Nov 26, 2006 7:08 pm
by black mariah
Alright, let's go down the list of things that are NOT wrong and are known to be right...

- The starter is good. I know these are notorious for frying starters, but this one's okay.
- There's definitely good compression going on. I'll bring a compression tester home tomorrow and get some hard numbers, but it's pushing air like a sunnuvabitch.
- Fuel is flowing just fine, all the way to the cylinders, but it's not flooded.
- There is spark at the plug.

Some things that are broken...

- The starter button will not work. When it's released the starter solenoid clicks and the lights that are on dim, but that's it.
- The front end lights do not work. The turn signals and headlight are toast (fuses are fine). Taillight works, and lights up under braking.

That's about it, really. I know that whatever's wrong can be fixed...

So I think it's $225 well spent. :mrgreen:

Posted: Sun Nov 26, 2006 7:17 pm
by Sev
Start with the simple stuff. Take the carbs off and try to blow air through all the passages... be careful about licking your lips afterwards ;)

It doesn't sound like it's anything electric (to me) yet. And there's no sense in pulling out wires everywhere if it's something as simple as a plugged idle circuit... speaking of which, is the choke working??

Posted: Sun Nov 26, 2006 7:36 pm
by Mintbread
Have you tried jump-starting it?

Posted: Sun Nov 26, 2006 8:02 pm
by black mariah
Sev: I'll give that a shot. The throttle is kind of sticky, so it may be something as simple as a fudged up carb. That would explain not firing, but wouldn't, to the best of my knowledge, do a damn thing for the headlight... which may just be burned out. :laughing:

Mint: Yes. Then I bought a new battery. Electricity isn't an issue.

Posted: Sun Nov 26, 2006 10:33 pm
by BuzZz
Do as Sev suggested and clean the carbs, they are likely gummed up after sitting for any length of time.

The starter problem..... the starter works, the switch works, but the selenoid just clicks and sucks power(lights dim).... you might want to check the seleniod. It sounds like it may be pooched to me.... from here anyways.

Posted: Mon Nov 27, 2006 5:36 pm
by black mariah
We have life... for a few moments. I sprayed some brake cleaner into the cylinders and it wanted to fire on that, but once that ran out it stopped. So yep, the carbs are gunked. They'll get torn down and dunked in a lovely carb cleaner bath tomorrow. The starter solenoid appears to be toast, so I'll dig around and see if there's one at work (I started working at a bike salvage place a few weeks ago... if anyone needs parts, I'm your hookup. :laughing: ).

Posted: Thu Nov 30, 2006 3:45 pm
by black mariah
The carbs were cleaned, so now the throttle feels better. But that's about all that's improved. It was running on one cylinder. First one, then the other. But never both at the same time. l*(DY(QY#Y(

Posted: Thu Nov 30, 2006 7:28 pm
by BuzZz
Wre the jets and small passages in the carbs cleaned as well? And how were they cleaned...... chemically or physically? If your carbs were gummy enough to affect the throttle feel, I bet the carbs were a varnish-fest. Chemicals probably won't get it.

The upshot of all that is.... I don't think your carbs are delivering fuel correctly yet.