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XS500 hard start problems


cegan09
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Hi, new here, hoping i can get some help.

I recently bought a 1976 XS500 off a friend (he bought a '97 yzf600 and needed to sell this one). We're having a lot of trouble getting it to start. I've never been able to get it to start on the electric start, but it did kick over when i got it. Now it won't start with kick or electric start. It will roll start, and when its running it runs like a champ, and pulls well.

I did disassemble and completely clean the carbs since they needed it badly, and have since put the correct jets back in it (main and pilot jets were changed over the winter during a rebuild, and correct sizes couldn't be found at the time). I've had them back apart many times to check and recheck, and i can't find anything wrong with them.

Once i can get my spark plug socket back I'm pulling the plugs to check them again (looked fine a week ago), as well as get an adapter so i can run a compression check.

Any suggestions on things to check?

Thanks

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It's an old enough bike to have a points ignition system - so check things like the points gap, dwell angle, and the timing. The points ignition is very high on the list of "Reasons why this old bike doesn't start well", but at least is easier to fix then taking the carbs apart again.

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The earthing bond is no good (ground) redo this and the battery connections. Also check the battery voltage as this has to be greater than 12.5 volts. The alternator should put out a minimum of 14.2 volts and make sure the spark plug leads are very clean along their length. If the points and timing are correct, and you have done the above, it will start easily.

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I think the main problem was timing. We did some playing and it starts now, still with some difficulty, but it starts. We need to actually set it correctly, probably tonight. Its popping a lot, but i think that is mostly due to carb adjustment.

thanks for the other sugestions, i'll be going over everything tonight to check connections and grounds.

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Well, she runs, and well. I think ignition was an issue. At least one wire was bad, temp ones on there, ordering new ones. Still needs some tweaking, like the idle is set for cold, so when it warms up it idles at 3k. I may also need a new coil since one is producing a much stronger spark than the other.

some pictures of the bike, i apologize for the poor phone pictures.

IMAG0007.jpg

IMAG0008.jpg

IMAG0009.jpg

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Hi, new here, hoping i can get some help.

I recently bought a 1976 XS500 off a friend (he bought a '97 yzf600 and needed to sell this one). We're having a lot of trouble getting it to start. I've never been able to get it to start on the electric start, but it did kick over when i got it. Now it won't start with kick or electric start. It will roll start, and when its running it runs like a champ, and pulls well.

I did disassemble and completely clean the carbs since they needed it badly, and have since put the correct jets back in it (main and pilot jets were changed over the winter during a rebuild, and correct sizes couldn't be found at the time). I've had them back apart many times to check and recheck, and i can't find anything wrong with them.

Once i can get my spark plug socket back I'm pulling the plugs to check them again (looked fine a week ago), as well as get an adapter so i can run a compression check.

Any suggestions on things to check?

Thanks

Hi

I'll agree with this the dwell & ignition timming needs to be set. to be able to bump start the bike & not start it via the normal methods does indicate this, if the bike runs well when started I would discount compression as with lack of compression the bike would have no performance

Regards Jim

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