Hi all


I've bought one of those cheap inductive tachs, the type where you just wrap the wire around the plug lead to give you a reading at the dial, to do some tuning on the engine with.


It wants to know the spark plug firing revolution to set it up. The options are ( Plug fires twice per revolution ) or ( Plug fires once per revolution )

I presume it is twice per revolution as I have a bog standard 2003 xl883 which is a dual fire I believe.


Thanks

jak...

 

I believe that 2003 was still dual fire. An easy way to tell is to count the wires (not the plug wires) going to the primary side of the ignition coil. Dual fire will be 2 wires, single fire will be 3 or 4 wires. 3 wires were used on early single fire systems, but current late models have 4 wires.

 

I believe all carbed EVOs in Sporsters were dual fire.

 

Sorry, but factory 04-06 Sporties are both carb'd and have single fire ignitions.

 

I stand corrected. Let me rephrase that. With the exception of late model Sportster 1200 and Twin-Cam 88 engines, all carbureted HD engines have been dual fire. I still think the OPs 2003 XL883 would be in this category.

 

Also, be aware that those may not always read properly (I have one myself). It will be accurate, then a little off, then accurate, etc.

This is because the dual fire it thinks is every 360 degrees of crank rotation, like in a wasted spark lawnmower or weedwacker. The HD dual fire system has 315-405 firing intervals. The tach sees this and treats them as 360, which throws it off a little.

 

Thanks guys


First off I dont know why I put 2003 ! the bike is a 2002 although in this case I dont think it mattered.

cHARLEY. RKZen.

Yes checked and is a dual fire. cHARLEY wires checked out as you stated.

Scuba10jdl.

Thanks, Yes dont expect it to be that accurate, thing only cost me £10. Not going to be a permanent thing, just an aid to set the bike up.