Question about 1979 Yamaha XS 500

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The battery in my 1981 Yamaha xt 500 runs flat how do I check the magneto or charging system of the bike

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You will have to get a digital volt meter,Harbor freight has them for $2.00, other stores like Sears, Radio Shack, any auto parts store will have them for various prices, you just need a cheap one that measures volts. Hook the positive lead up to the positive battery terminal, and the negative lead to the negative terminal, read your battery voltage should be from 11.90 volts to 12. 98 volts. Start the bike and measure the voltage while running, voltage should go up to 13.5 to 14.8 volts. If the voltage goes up the bike is charging, if it stays the same as when it isn't running the bike is not charging.

Posted on Aug 28, 2009


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Gino Cussen

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SOURCE: Need Yamaha XT 500 Wiring diagram for pipe cart I,am building.

This is the best i can do, its the manual in photo form. You can enlarge using any photo editor.Good luck. Rate me if i've helped you. thanks.

Posted on Mar 26, 2009



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SOURCE: 1981 Yamaha XS 850 triple tranny stuck, simple

Thanks to everyone responding, I think I'll walk way from this one, save me time money and frustration.

Posted on Jun 06, 2009

ollie reece

ollie reece-jones

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SOURCE: Yamaha xt 250 with no spark

no buddy you need 4 thing for a spark -magneto,cdi,coil,spark plug check the plug 1st replace this and get back to me

Posted on Sep 26, 2009


Greg O'Day

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SOURCE: 1981 Yamaha XJ750 Seca Trouble Starting it

Battery conections need to be checked even the ground wire.

Posted on Oct 01, 2009


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SOURCE: how do i set cam position and timing on an old yamaha xt 500

You didn't say WHY the cam / valve timing needs to be reset. For some reason I get the feeling someone told you that resetting was needed and so you are asking how. Obviously, you may have installed new pistons and that is why the resetting is needed. In either event, when the cam timing is set the valve timing is also set. Other than adjusting valve lash, setting the cam sets the valve timing. Below is a web site where you can do a free download of a factory service manual. The process is not hard but having a manual will be more help and faster help than I can give online.

Posted on May 27, 2010

Testimonial: "Thanks for your reply. I've been to the web site before and downloaded the manual already. It does not really cover the situation I have. There also seems to be a lack of compression with the bike. A friend has lent me a workshop manual so I will try that in the mean time. Thanks again "

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How do I replace the magneto, I am only getting 12 v. out of my battery, and when I disconnect the pos cable it dies, so the magneto must be gone.

First off that is not how you check your "charging system" not a magneto! on these bikes you have a Stator that is in the LH side cover on that engine and you need to check the windings for continuity and for short to ground. I would consult a local dealer for voltage output test spec's on the stator. next is the regulator rectifier, this can be tested with a meter and again consult your dealer.

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