Hello all, I am new to the site and new to this engine. I am amazed as to what some of you have done with these engines. I have been searching and reading for days looking for an answers. Lots of discussions on ignition systems but most talk about upgrades. I have a 13B installed in a boat. Mud boat to be exact. Made to run through shallow water mostly used for hunting. It is a marinized Mazda engine built by Rotary Power Marine that is no longer in business. The engine looks to be an 86-88 because of the water pump design, but the ignition looks like its from an 84-85. It has a distributor and two round coils. I have searched and searched for replacement coils. One site says this is the coil to use on newer engines with older distributors but no explanation of why or a difference. I would like to stay with the current ignition set up and it runs well. I just like to have a list of parts ready to go.

 

The difference in the water pump is probably where the company switched to an s4/s5 neck or something. I can't remember the exact part that's swapped or why but I do know it happens. As for the coils I believe atkinsrotary sells first gen coils that may match what you're describing (SKU "MT-COILS").

 

Hey thanks for responding. I just happened across your page an hour ago (Very Nice). Then I saw that you responded to my question. I was wondering what area of LA. I'm in Houma. I saw the one old style coil Atkins offers but was wondered why only one for so many different possibilities. So many on this forum use lots of different coils from cheap to expensive. I have read through hundreds of threads and worried about damaging other ignition parts that would be hard to replace. Lots of threads warn of that. My coils and engine run fine but I want to have spare coils handy. Not wanting to rely on Auto zone to guess for me. The coils I have are unmarked and only have two studs. I tried to post Picture but hadn't figured that out yet.

 

Picture (img)https://cimg7.ibsrv.net/gimg/www.rx7...8952eac8bd.jpg(/img)

 

This link doesn't work, all I get is an error page.

Also i'm located near the Alexandria area.

 

yes I was trying to download the picture and now I want to clear it. I know its probably simple but I'm not wires that way I guess. I would think that I could delete it in edit I think it works now but its small

 

The stock ignition system, on a whole, is great. It's reliable and can handle a decent amount of engine upgrades. The stock coils (Diamond) are also great. That said, don't feel limited to them. Assuming you have replicated a complete Gen 1 (SA/FB) system, you should be good. I've been messing with these cars for over 30 years now and I've only (personally) known of maybe 2 Diamond coil failures. I used MSD Blaster coils for many years, not because of stock failures but because when you're young and don't know any better, you want "upgrade" everything. The MSD coils worked just fine - no different than stock. I had a friend or two that had failures with Accel and I think Jacobs, but who is to say why they failed? We had different mindsets then. My point is you have options out there.

Many of the failures I read about were people using amplifier boxes (like MSD or Crane), but it doesn't sound like you're trying to do anything like that, so I wouldn't lose sleep over using an aftermarket coil if that's what you end up getting. I would endorse using MSD Blasters if they still make them based on my experience with them, and for that reason, I couldn't speak on any other brands. One other thing to mention is make sure your wires are always in good shape.

 

Thanks Diabolical for responding. I have confused the _rap out of myself. I want to carry a back-up coil and other supplies being i'm on the water where not many will find me. My distributor looks to have the j109 igniters wired to the positive of each coil. Distributor also looks like others I have seen on the internet as stock. When I search for Coils compatible to a 1985 distributor Beck, Spectra, United, Standard, NGK, Airtex pop up but not the others such as Accel and MSD Blaster. Diamond must not be around anymore. Also I do not have external resistors that I can see. So my coils need it built in right? Most of the coils in the list say that they need external resistors or some say used with external resistors. I was told that the engine package came with heavy duty coils. I'm guessing epoxy because of marine use. I am probably wrong on that. Thanks Doug,