While I was getting my bike dyno'd the tech mentioned that a common issue is the plug wires rubbing the insulation off in a couple areas, and sure enough it was happening to mine. On the front cylinder a couple inches back from the boot the plug wire rubs against the bottom of the tank/frame area, and on the back plug wire, it rubs on the front plug wire right where they cross each other. I can see the front one really being a problem in the near future. I have 18K on mine and was surprised how much of the insulation had rubbed off. I just built some 3" sleeves to wrap around them. I picked up some vacuum line at the auto parts store, cut it to about 3" and then slit down the middle. Wrapped it around the plug wire where the wear is occurring and snugged it up with a couple tie-wraps.

Could prevent having to troubleshoot an odd misfire down the road....

 

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Thanks for the suggestion.

BTW,since you said there's already some of the insulation worn off the plug wires i'd replace them if it were my bike.

They arent expensive at all and now that you made up some protective sleeves that would protect the new plug wires.

Get some aftermarket spiral core wires that are still shielded to stop static issues with electronics but they also have metal wire that wound arround a suppression core that allows much more current to reach the plugs then stock suppression core wires do without the spiral wound metal wire.

And with your bike having plenty of performance mods that increase power spiral core wires would be a good inexpensive addition to your bike,irridium plugs with the spiral core wires would be another worth while upgrade resulting in a dbl upgrade if you do both at the same time.

Irridium plugs last a lot longer then std plugs and also require less voltage to fire then std plugs too.

BTW,the rubber vac line you used to cover wires isnt designed to be close to extreem heat like the cyls/heads on an air cooled HD creates and will likely melt on a hot day when motors real hot .

You can buy blk color insulating sleeve for plug wires in diff length's that's designed to take the heat and protect the plug wires from extreme heat
from autozone,summit racing online,etc.

Happy motoring!

Scott

 

Nice tip and a good reminder to get in there and look around.


Late model bikes use ion sense to determine the state of burn in the combustion chamber- this relies on stock spec wires and plugs or the ecm may be confused by unexpected resistance ( more or less)

There have been more than a few riders who switched to "performance" plugs/ wires ( even screamin eagle) and had drivability problems.


Mike

 

Vacuum line was designed for heat conditions - it's usually attached to the intake which does in fact get hot.

Now if you try press it against hot exhaust... yeah, but just running over the cylinder heads it should be just fine - that's what it was designed to do.

Also, like Mike said, stay with factory plugs and wires. Been down that road. Wasn't fun.

 

I'm curious, was the paint and clear coat on the bottom of the tank as it should be?

 

I had my bike in for the clutch recall and the front brake master cylinder was seeping also so i had them fix that also. The front spark plug wire was also rubbed thru about half way to the core so i pointed it out to them and they had to order it. Its on national back order as of last month in Oct. They finally got the new wire in Nov. Bike finally gets delivered back home to me today just in time for the freezing rain... YAAA....

Batman

 

Yeah I fell for the "performance" plug wire crap. Kept getting engine codes and fuel mileage went south. It couldn't be those brand new, fat, cool colored, plug wires that I just installed...LOL It was

I went and bought the SE plug wires and it cured the engine codes....now you guys are saying that even those plug wires can cause problems as well??? CRAP!!

 

I've had no problems with the SE Fat versions. I bought them because the OEM ones were out of stock.

Will note that there was No performance/mileage gain at all though... just for looks I suppose.

 

I would expect that Harley would spec the SE wires the same as stock so the ECM isn't confused. But there goes any advantage they may have...

 

See this thread https://www.hdforums.com/forum/new-r...plug-wire.html