More electrical issues with the GR

[Guest]

Probably not a good thing when you can pull the left sparkplug wire off and not change the way the bike is running.

Pull the right and the bike quits running immediately.

Looks like more quality time with the multimeter for me.

[pete]

Probably not a good thing when you can pull the left sparkplug wire off and not change the way the bike is running.

Pull the right and the bike quits running immediately.

Looks like more quality time with the multimeter for me.

Bugger! That's exactly what I just fixed on the 450 and I had the worst case scenario... Dyna S busted...

Typically though it should be nice and simple like a dodgy spark plug cap.

Good luck!

[oldrookie]

Thanks, Pete.

Seems like it idles okay until it gets warm, then it starts to miss. Not sure how to isolate the issue.

[oldrookie]

Just checked the coils re: the manual. Primaries check out ok.

Between the positive and the secondary (spark plug cap) there is some difference between the coils. The left coil was reading 23.9 ohms between the positive and spark plug cap. The right side was reading 34.7 ohms.

May not mean anything, since the manual says there aren't specific preferred readings, but the lower ohm reading would indicate there is more resistance in the left coil and that might result in less accurate firing at the plug...I think.

Looks like it is time for the coil relay mod and a serious effort to clean all the bullet connectors/connections on the bike.

[pete]

So when it's cold, everything's good on two cylinders? Then when it warms up, does it die completely on one side or does it just start misfiring? Is it always the same side?

Have you replaced the spark plug caps any time recently? Maybe just trimming the end of the spark plug lead and putting new plug caps on will be enough, especially if they're old...

Otherwise, yeah, cleaning and tidying all that wiring under there is probably going to be the next logical step.

Measure the voltage at both coils and if it's within half a volt of the battery voltage I wouldn't bother with the coil relay mod until you've diagnosed the issue.

[oldrookie]

Well, mostly happens when it is hot, but it was doing it cold last night.

Haven't replaced the caps, that was the next step, but the coil relay mod was already in the pipeline. Relay has been sitting in the garage for a couple of weeks.

I'll check the voltage when I get home from work.

[oldrookie]

May have been the plug caps. Replaced them with NGK caps and it seems to run better. Going to go take it for a run and get it hot and see.

[pete]

Good stuff, they make a huge difference if they no longer bite into the lead properly or get corroded inside.