Pertronix Ignition Conversion

[txrdb]

I am changing to a Pertronix pointless ignition on a Mercruiser 888 (Ford 302). I want to use one of the Petronix Flamethrower Coils also. Is there such a thing as a "marine coil", or will their standard coil be acceptable. I was going to buy the epoxy filled model versus the oil filled. Thanks for any help !

 

[JasonB]

Re: Pertronix Ignition Conversion

I did this conversion last year. The epoxy filled is what you want. I'll save you some time with this conversion. Get the Ignitor II and whichever coil you want (I used the standard flamethrower), and a new set of Magstar wires (overtons.com ~$35), and a new cap/rotor combo. Cut the ballast wire (tan wire running from old coil to the choke on the carb. Now run a 14-16ga wire from the key on post on the keyswitch directly to the coil. I spent hours figuring this one out. There wasn't enough voltage otherwise (possible bad wire, but this is easier than chancing it).<br /><br />Your tach will likely be way off after the upgrade. I am working on a possible fix. Your timing may also change by a couple degrees. I also found that the extra rotor I already had fit better than the one in the pertronix kit for my Prestolite Clip cap distro.<br /><br />Well worth the upgrade as the engine now starts much easier and doesn't have the miss that it used todue to the old coil breaking down.

 

[txrdb]

Re: Pertronix Ignition Conversion

Thanks for the reply. Two questions...How does the electric choke work if you cut the wire to it? and how far is the tach off?<br />Thanks

 

[highaltitude]

Re: Pertronix Ignition Conversion

did this change effect the shift interrupt switch???

 

[JasonB]

Re: Pertronix Ignition Conversion

The wiring runs as such: A full 12v comes into the the connector on the choke. The ballast wire is tied to that 12v lead inside the slide connector and runs reduced power to the coil. Cutting the ballast wire doesn't affect the choke because the power comes on the first wire. While it may be tempting to pull your 12v from this wire, but it never worked right for me. The engine would run fine for 30-45 seconds, then the pertronix would shut off, but was able to immediately restart. That's why I suggest just running a dedicated lead. If your boat is like mine and doesn't have a safety kill switch, this lead would be a good place to put one since cutting the power will kill the engine.<br /><br />My tach now stops reading past 3400rpm or so. I know I'm still turning the same R's because my GPS speed stayed the same and I was turning 4050 before the conversion.<br /><br />The conversion doesn't affect the interrupt switch on my Mercruiser, but requires a small "fix" to work with OMC units. I have built the "fix" to see if it helps the tach problem as all it does is filter the signal a bit. All the parts cost me ~$3 at Radio Shack and a few minutes of soldering.

 

[sculbert]

Re: Pertronix Ignition Conversion

Thanks for the input guys, I just ordered one for my 165 merc. I got it running the other day and it sounds like you had problems like I am running into also. My engine is missing randomly. I figured the coil was breaking down. As well as it has the nasty old points in it. I went to the web site and read about the Ignitor II and Flame Thrower II coil. sounds great and sure hope it works as good as it sounds. Looks like I ight pick up an extra 7 to 10 horses also. That would be good. 150 dollars for both isn't bad I don't think. Or at least hope. For a complete Distributor and Coil replacement it seems fair.

 

[Rainmaker]

Re: Pertronix Ignition Conversion

Don't know if this is a factor but I have heard that the Coast Guard frowns on high voltage coils unless they are part of a marine-approved ignition system. Maybe someone can substantiate that rumor.<br /><br />I still used a 40kv coil and .045" spark plug gaps on my old 165 with very good results.

 

[JasonB]

Re: Pertronix Ignition Conversion

Good point about the plug gap. Go ahead and toss in a new set of plugs and add .005 to the original gap spec. For the 888/302, there is a set of Autolite (Ford) plugs that I like better than the Delco 43T if that is what your engine uses.<br /><br />I'm not sure about the coil. When I ordered mine, I explained what I wanted to do and the epoxy coils are the ones I was told I needed. They were careful to point out that the Pertronix wires that are available for purchase are NOT marine approved, so I bought the MagStars which are marine approved, noise shielding, and self-extinguishing. I used set 35038 from Overtons, http://www.overtons.com/cgi-bin/overtons/order/items.cgi?spec+2C2E, for my Ford 302.<br /><br />I am very happy with the $175 or so spent on this upgrade. I'm hoping to try my tach fix soon.

 

[txrdb]

Re: Pertronix Ignition Conversion

JasonB - Let me know how the Tach fix goes, and what you did. I am not an Electronics wizard...

 

[cobra 3.0]

Re: Pertronix Ignition Conversion

I did the Pertronix conversion on my 3.0 Cobra. Flamethrower II epoxy filled coil(suited for higher vibration environments) and Ignitor II with Accel High performance 8mm wires. It is smoother, but not one mile per hour faster. Was it worth it? Hard to say... I'm glad the points and condensor are gone...that's about it.

 

[merc200]

Re: Pertronix Ignition Conversion

Hello Everyone-I posted a while back because I thought that the petronix system I had installed onto my merc 165 had screwed with my tach. Come to find out, the tach wasn't set for a six cylinder engine in the first place! It now reads right on with my friend's snap-on timing light. The wire that goes to the coil from the key switch most likely has a resistance wire in it. You can tell because the wire is real shiny. The resistance wire isn't very long......mine went to about the length of the valve cover in the wiring harness. I just peeled the covering off the wires, cut the resistance wire off, and replaced it with a 14 gauge wire and connected it to the coil. My petronix-I and flamethrower-I coil work great....I just have to remember not to leave the key on, or the module will be toast!

 

[JasonB]

Re: Pertronix Ignition Conversion

Thanks for teh info Merc200. That will be easier to try than my plan. I'll give it a shot and let everyone know.