Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

[blkzoe]

Replaced my points with the Petronix Igniter II / Flame Thrower II (0.6 ohm) breakerless ignition over the weekend. Twin Mercruiser 470's (1986, 170hp). What an improvement in performance. Think smoother running throughout the RPM range in addition to a quick/stable start-ups. I actually believe my gas milage has drastically improved, but that's to be determined over several runs/fill-ups.

Here's the issue. I've been reading several older posts concerning the purple choke wire to the coil. Many say replace the wire as it's a 1.5 ohm resistance wire that may shut down your system acting as a voltage thief. Most, if not all, of the posts reference the Igniter, not the Igniter II. Igniter II has apparently addressed many of the original Igniter's problems (i.e., key left on).

My question: Should I still replace the original 1.5 ohm purple choke wire with a wire with less resistance in my Igniter II system?

Thanks to all........

 

[alldodge]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Replaced my points with the Petronix Igniter II / Flame Thrower II (0.6 ohm) breakerless ignition over the weekend. Twin Mercruiser 470's (1986, 170hp). What an improvement in performance. Think smoother running throughout the RPM range in addition to a quick/stable start-ups. I actually believe my gas milage has drastically improved, but that's to be determined over several runs/fill-ups.

Here's the issue. I've been reading several older posts concerning the purple choke wire to the coil. Many say replace the wire as it's a 1.5 ohm resistance wire that may shut down your system acting as a voltage thief. Most, if not all, of the posts reference the Igniter, not the Igniter II. Igniter II has apparently addressed many of the original Igniter's problems (i.e., key left on).

My question: Should I still replace the original 1.5 ohm purple choke wire with a wire with less resistance in my Igniter II system?
Thanks to all........

Yes, replace the wire and run a full 12V connection. The Petronix Igniter II is to be installed without the resistance wire.

 

[haulnazz15]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Agreed, you need a full 12V while running. Now, normally the choke wires still get 12V all of the time, it's the old ballast wire that runs to the distributor that causes the drop in voltage. I'd run a multimeter on the wire while the engine is running to verify that you have the lower voltage wire in place.

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Agreed, you need a full 12V while running. Now, normally the choke wires still get 12V all of the time, it's the old ballast wire that runs to the distributor that causes the drop in voltage. I'd run a multimeter on the wire while the engine is running to verify that you have the lower voltage wire in place.

But there's no ballast wire (or ballast). I know what system you're referring to (exterior ballast). I apparently had an interior ballast on the old coil. Now what?

 

[alldodge]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

But there's no ballast wire (or ballast). I know what system you're referring to (exterior ballast). I apparently had an interior ballast on the old coil. Now what?

Coils don't have internal ballast resistors, they are made to run with or without a ballast resistor. If you did not have an external ballast resistor then you have a ballast wire. The ballast wire is purple, looks like just a regular wire but is actually a resistor. With the engine running measure your voltage on the + side of the coil, it should be 12V. If the reading is below 12V replace the wire with another going back to the choke

 

[haulnazz15]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Are you sure? The ballast wire looks like a regular wire, it just has a resistor inside the wire sheathing. Unless you are positive that it isn't a ballast wire, I'd be checking it with a multimeter. Otherwise, you'll burn up the Pertronix unit when it's trying to get 12V from a 9V hose.

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Coils don't have internal ballast resistors, they are made to run with or without a ballast resistor. If you did not have an external ballast resistor then you have a ballast wire. The ballast wire is purple, looks like just a regular wire but is actually a resistor. With the engine running measure your voltage on the + side of the coil, it should be 12V. If the reading is below 12V replace the wire with another going back to the choke

Ah, that makes sense.

One last question. Why are my engines running so well w/ the purple wire attached?

 

[haulnazz15]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

The Pertronix unit will still "work" with the reduced voltage, but eventually you will burn it up.

 

[stonyloam]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

I do not believe you will "burn it up", but the Ignitor II should have a full 12 volts to work properly. You can remove the purple resistance wire that runs from the choke connector to the coil +. Splice a stranded wire to the purple wire going to the connector and run it to the coil + for a 12 volt source. Best to use a solder connection and coat the splice with Liquid Tape to seal it from moisture.

 

[JimS123]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Although my Pertronics is a different model, it came with very detailed instructions on how to install it. Didn't yours?

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Although my Pertronics is a different model, it came with very detailed instructions on how to install it. Didn't yours?

Yes, detailed instructions. But no mention of the purple choke wire issue.....

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Yes, detailed instructions. But no mention of the purple choke wire issue.....

Re-read the instructions (multiple times). Now I see, but don't I lose my choke by bypassing the purple resistance wire?

 

[nola mike]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Re-read the instructions (multiple times). Now I see, but don't I lose my choke by bypassing the purple resistance wire?

No, the resistor wire is feeding off the choke (not vice versa)

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

No, the resistor wire is feeding off the choke (not vice versa)

OK, going w/ figure #2.

 

[stonyloam]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

OK, going w/ figure #2.


View attachment 212389

Go with figure #1. Remove the resistor wire and go directly to the coil + with a regular stranded wire from the choke connector. Attach the red Ignitor II wire to the coil +. You do not need the resistor with the 0.6 ohm Flamethrower II. The purple wire going to the choke connector is 12V from the ignition. #2 is used if you kept the original coil or the 1.5 ohm Flamethrower (not Flamethrower II) coil.

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Go with figure #1. Remove the resistor wire and go directly to the coil + with a regular stranded wire from the choke connector. Attach the red Ignitor II wire to the coil +. You do not need the resistor with the 0.6 ohm Flamethrower II. The purple wire going to the choke connector is 12V from the ignition. #2 is used if you kept the original coil or the 1.5 ohm Flamethrower (not Flamethrower II) coil.

Re-wire and fired per Figure #1. Timing checked and adjusted. Very smooth. Idles at 650 rpm with no misses. WOT later this evening or weekend.

 

[blkzoe]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Ok, as long as I'm upgrading the ignition system, any suggestions on plug wires? Magstar Marine Spark Plug Wire Set?
Also, I've read about increasing the gap on the stock plugs from .035 to .040. Has anybody else done this?

 

[alldodge]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

Ok, as long as I'm upgrading the ignition system, any suggestions on plug wires? Magstar Marine Spark Plug Wire Set?
Also, I've read about increasing the gap on the stock plugs from .035 to .040. Has anybody else done this?

Don't get taken in by marketing hype.
Exp: A "flamethrower" 40KV coil has to be better then a regular "Mercruiser" 40KV coil
Exp: A "magstar" wire set has to be better then a "Merc" or standard "industrial" wire set.
Exp: A "Nitro wizbang 5000" has to be better then a something else

They are all the same so long as they are made from the same material (silicone jackets, etc). Your boat was designed for .035 going to .40 will cause a longer spark, the gas may burn quicker, and you may even damage the engine due to preignition. The fuel burn is designed to work properly, changing things may help, may not, in the end you will either enjoy it or be paying for it later.

 

[stonyloam]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

I would go with the OEM Mercruiser wires #84-816761Q6. They are high quality and they fit perfectly. Well worth the few extra bucks they cost.

 

[Jacalore]

Re: Petronix Igniter II / Flame Thrower II (0.6 ohm) on my 470's

I do not believe you will "burn it up", but the Ignitor II should have a full 12 volts to work properly. You can remove the purple resistance wire that runs from the choke connector to the coil +. Splice a stranded wire to the purple wire going to the connector and run it to the coil + for a 12 volt source. Best to use a solder connection and coat the splice with Liquid Tape to seal it from moisture.

I did this on my 3.0, wouldn't work otherwise.