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Discussion Starter #1
I just added an aftermarket tachometer to my Sportster and I'm only getting 1500 RPMs at 50 miles an hour 5th gear, is that right? Idles at 500.
 

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Senior Flatulant
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Sounds like it may be 'mis-set'.

On many tachometers, there a switch, screw or jumper to adjust for the number of cylinders. (1 cyl., 2 cyl., 3 cyl., 4 cyl., etc.)

You may have to remove the housing to get to it.

Cheers,
Smoketown
 

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^^^ Yup, its only giving a reading of half the RPM
 

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Is the tach, made for Harley's? If so what years? Early Harleys are dual fire,( both plus fire at the same time) newer ones fire each plug separately. Check the years your tach is made for.
 

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Discussion Starter #5
I found out it is a single fire ignition have to buy a separate adapter that runs both of the coil wires together into one..
WTF how about make a motorcycle tach that works on all types 1cyl to 8cyl
False advertising.
 

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Some tach do work on all combinations, but it's up to the user to buy the correct one, or to set the set the switch to the correct setting.
 

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Senior Flatulant
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He had s list of what it worked on. My bike was listed. Guess im a dumbass for believing the written word. My bad.
Back in the day, I bought a large chrome Sun tach with a metal housing for one of my cars.

The catalog listed all of the American autos it worked on.

When I received it, the instructions had an alphabetical list of cars followed by the 'adapter' number needed to make it work.

Danged adapter to make it work cost more than the tach did.

Sent it back.

I didn't read the fine print.

Cheers,
Smoketown
 

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Discussion Starter #10
Ok got it figured out. I have a single fire coil & have to combine front & rear signals together using a adapter rig.
Made the adapter rig they showed of a resistor & diode on each cylinder signal wire & all together to tach green. Idling around 900 now. Much better but will check it for accuracy.
 

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2004 Ultra Classic
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He had s list of what it worked on. My bike was listed. Guess im a dumbass for believing the written word. My bad.
I had a tail light stolen off my 2007 Chevy truck and they sent me the wrong one. Anyway they bitched that I did not compare the picture and that in that year there were 2 different ones used! I just checked that it said it would fit my year/model truck. I had to tell them to fix their add to emphasise that this was a split year. Like Joe schmoe is going to know 2 different tail lights were used that year.
 

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Discussion Starter #12
Anyone know difference between single fire vs dual fire. Im confused. Is that cheaper to produce? Does it increase performance? I was told my 06 883R came with dual fire and someone changed it over to single fire. Why!!!
 

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Dual fire - Fires both cylinders at the same time.
Single fire - Fires each cylinder independently of the other.

Stock dual fire is used cause its cheaper and simpler.

Single fire doesnt have any wasted spark, and will smooth out the idle somewhat.
 

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Wayward Son
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Dual means both plugs fire simultaneously.

Single is only one plug when it is supposed to.
Really extremely marginal performance gain, if any, with single fire.
Perhaps a bit easier starting.
 

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Another echo ???
 

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Wayward Son
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Who told you that?
 

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Wayward Son
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