[firehawk]

Kicking around adding a tachometer and I can't seem to find out if the '06 VLX is a dual fire or single fire ignition. The tach I'm looking at has an adapter for single fire but just would like to know if I'll need to use it or not.

Does the 600 fire both coils at the same time?

 

[Pete Sake]

Kicking around adding a tachometer and I can't seem to find out if the '06 VLX is a dual fire or single fire ignition. The tach I'm looking at has an adapter for single fire but just would like to know if I'll need to use it or not.

Does the 600 fire both coils at the same time?

Wow 6 years and still no answer. It seems many do not know and those who do answer other related posts admit they are not sure and guessing.. so no help. I am interested in installing a tach on my 05 VLX and here is the most accurate info I have found.

The term single or dual fire has nothing to do with how many coils or if they fire at the same time. What dual fire means is there is a spark on the compression stroke for power, and another on the exhaust stroke for "reasons". It seems the VLX 600 is dual fire so if you use a tach meant for single fire it will 1/2 your RPM readings and be inaccurate. So you would not need the single fire adapter if using a dual fire tach.

I would think by now you already figured it out but I responded in case anyone else in the same position comes across this post for an answer like I did.

 

[swifty2014]

Thanks for the info. Yes it is a quandary in wording. These bikes have 2 coils but each is fired on the cylinder they are dedicated to . Almost like 2 separate 1 cylinder engines connected together at the crank. But since they fire 2 plugs on each stroke it can get confusing. Dual cylinder, dual coil, dual plug,dual spark, dual fire.
A lot of guys have put on a tach and it works fine.

 

[CSRoad]

I didn't start lurking here until 2015 so the OP predates my arrival.

Two I know about for sure the 750 ACE and the 650 Hawk GT both fire on the exhaust stroke and both will still run fine, but sound weird with one of the camshafts 180 degrees out.
Of note is the fact that the ACE has common connecting rod journal alignment and the Hawk GT is offset both are single ignitor/pick-up, notched reluctor setups, the ICM units are different obviously.
I'm guessing the ICM being crank triggered can't be bothered to sort out which stroke is which and fires every revolution.

So ask me about others like the VT600C and all I can do is guess, I'd guess they all behave the same, but I would not advise somebody's tachometer purchase based on my guess.
It is good to hear that at least some of the VT600 years behave that way too.

The fuel injected bikes may be smarter with more sensors and a more precise brain box, what's the guess on them?

 

[h13man]

Firehawk went to a Harley Sportster in 2016. Haven't heard from him or Stranger since.

 

[Pete Sake]

Well mine is an 05 non fuel injected single carb. I am going to try a dual fire tach based on what I could find out and report back if it works. It may be a while though since I have a ton of other things to do to it first.

 

[Pete Sake]

I didn't start lurking here until 2015 so the OP predates my arrival.

Two I know about for sure the 750 ACE and the 650 Hawk GT both fire on the exhaust stroke and both will still run fine, but sound weird with one of the camshafts 180 degrees out.
Of note is the fact that the ACE has common connecting rod journal alignment and the Hawk GT is offset both are single ignitor/pick-up, notched reluctor setups, the ICM units are different obviously.
I'm guessing the ICM being crank triggered can't be bothered to sort out which stroke is which and fires every revolution.

So ask me about others like the VT600C and all I can do is guess, I'd guess they all behave the same, but I would not advise somebody's tachometer purchase based on my guess.
It is good to hear that at least some of the VT600 years behave that way too.

The fuel injected bikes may be smarter with more sensors and a more precise brain box, what's the guess on them?

As far as the question regarding fuel injection. I can state that in my normal job of installing aftermarket automotive crap we often have to find a "tach signal" when installing remote start units as it lets the brain know the engine is running and the RPM. We can often use a pulse wire off a fuel injector and it suffices to give a tach signal. But, not always. Some give a "clean" signal, and some not so much and can cause faulty operation and shut down.

So, the best advice is to try it on a case by case and see if it works. One of those things you don't know for sure until you try and it won't hurt anything if it does not work.. it just won't give accurate RPM if it doesn't. Just have to make sure you hook the tach signal wire from the tach to the injector wire that pulses. Normally each injector has 2 wires... the common one is the same color on each and the pulse is a different color on each so connect to one of the different colored wires from an injector to test.