'84 GS550E no spark...

[jayzed]

Hi
I am trying to get my newly acquired gs550e started and am not having any luck.
The battery is dead and I can't get a new one until next week, so I am boosting it from my car battery (car not running).
It turns over nicely, even almost fired up a couple times at first.
After several tries I decided to check the spark. It had a faint spark, so I tried it again. Nothing. Checked the spark again and now there is none. Checked the plug on the opposite side and had one tiny spark and then no more... What should I check now??

I will have to email the chick that I bought it from, as she assured me that it ran fine and only needed a battery and an oil change.

Thanks
J

[t3rmin]

The ignition on these bikes is very flaky. I'd suggest doing a search through the archives and checking your ignition components thoroughly. If anything's bad, consider doing the Dyna S conversion (for which you'll also find lotsa info in the archives). Good luck!

[mcan]

Just a thougt, was the first plug reconnected and grounded when you checked for spark on the second plug? Since 2 plugs are fired by one coil and one secondary winding, if you happened to be checking for spark and the opposite plug is not connected, then the gap for the spark to jump would be excessively large and you would not get a spark. On my 83 GS550E, the two outside cylinders are connected to the same coil so I'll bet that's what happened.

[jayzed]

Just a thougt, was the first plug reconnected and grounded when you checked for spark on the second plug? Since 2 plugs are fired by one coil and one secondary winding, if you happened to be checking for spark and the opposite plug is not connected, then the gap for the spark to jump would be excessively large and you would not get a spark. On my 83 GS550E, the two outside cylinders are connected to the same coil so I'll bet that's what happened.

You could be on to something there.... I did have both of the plugs out at the same time.
The spark did seem weak though, when I first checked it. The plugs don't look too old, but maybe I should replace them. Do I need to remove the gas tank to change the centre plugs?

Any other tips for starting this bike? I sprayed some WD40 in the cylinder, and sprayed some in the air intake...

I'm guessing that the gas is on when the switch is horizontal... is that correct? And is pointed down for reserve?

thanks guys

j

[mcan]

You do not have to fully remove the tank to change plugs, though I found it helpful to remove the two bolts at the rear of the tank and prop up the rear with a piece of wood. That gives you a little bit of extra clearance for your hand. I found that you have to assemble the tools together in the bike like this: First insert the spark plug socket then snap on a short extension and then snap on the ratchet. You can't tilt the whole assembly in the pockets at once. If you have compressed air it would be wise to blow out the spark plug pockets to remove any loose debris that might try to fall into your engine when you remove the plugs.

Unless the plugs look terrible (filled with cabon or depsits) or if they look damaged (cracked or missing center ceramic or severly bent tang) I would brush them up and regap them to 0.024 to 0.028 inches and reinstall.

There is a trick posted that says that you can assist the fuel delivery for starting by blowing into the carburetor vent tubes prior to cranking the engine. There are two tubes that run up near the battery one on each side they are black an about 3/8 inch in diameter with a really thin wall. Give each of them a puff of air and that will force some extra fuel into the intake tracts which should help your bike start.

The petcock handle positions are:
1. Long part of handle down...normal fuel flow or "on"
2. Long part of handle forward....reserve position
3. Long part of handle rearward...prime position..This bypasses the vacuum shutoff valve that is built into the fuel petcock and allows fuel to flow when the engine is not producing sufficient intake vacuum. In your case I would put the petcock in the prime position since the engine does not produce much vacuum when cranking.

Good Luck[-o<

[jayzed]

Thanks for the tips! I'll pull and gap the plugs and l see if I can it started today.

I'm still not sure about the fuel petcock though... my options seem to be:

- arrow pointed downwards
- arrow pointed rearwards
- arrow pointed upwards

I'll keep it in the rearward position, that is where I had it yesterday.

J

[Steve]

Sounds like somebody re-assembled the petcock arm about 90 degrees off.


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[jayzed]

Sounds like somebody re-assembled the petcock arm about 90 degrees off.


.

Is that possible?? If so then I guess "up" would be prime....

Maybe the plastic petcock cover was put on in the wrong position. I'll take it off and see what the petcock itself is showing.

I just read in another thread the bike probably won't run with the airbox removed. I had the side cover wide open all day yesterday... will try it closed today.

j

[Steve]

"I just read in another thread the bike probably won't run with the airbox removed. I had the side cover wide open all day yesterday... will try it closed today."

The bike will usually start and idle with an airbox removed, but won't do much beyond that.

If the airbox is installed, but no filter, it will do a little better.

It runs best with filter installed and all access ports closed and sealed. This gives just the right amount of restriction to smooth the airflow to allow the carbs to do their jobs.

If you have the airbox completely removed and want to do a quick test, fold a shop rag in half, drape it over the carb inlets, use wire ties or hose clamps to hold it to carbs 1 & 4. This works for quick tests, but I would not use it for adjusting any jetting.


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[jayzed]

Got it running!
Changed the spark plugs and figured out which position was the prime and it fired right up!
Seems to run fairly well, but I need to keep the choke partly on or it won't idle or even rev up very well.
I don't know how old the gas is, so I will drain the tank and add fresh fuel.
Is it simple to adjust the air/fuel mixture? What else should I try, before removing the carbs and cleaning them prooperly.....

thanks
J