So Ive told by a couple people that you can fit a gear reduction 2nd gen starter in a 12a engine...... i have a bridgeport and need to turn fast to make for easier starting. My family owns a starter and alternator repair shop and we can order them brad new. In our book there are2 different kinds of starters..... a 12 tooth and a 13 tooth. The 12as are 11 tooth so which one will fit!

 

Were pretty sure the 12 tooth is the one that will work but I just wanna make sure.

 

From what I remember, ANY S2-S5 NA starter will bolt and line up with any S2-S5 flywheel. I have an S4 starter on my S3 engine and have no problems whatsoever. DOnt worry about teeth counts, the spacing is correct and will mesh correctly.

 

My advice would be to also run new, extra-fat battery cables, as our thin, aging japanese stuff is minimal at best. I like to run 6 gauge for battery to ground and battery to solenoid, and although I have never taken the time, I bet you could see some small improvement from a larger piece of wire from the solenoid to starter. Just my 2c, Ben

 

I agree, I used a spare starer from my 83 12a on a S5 NA engine and it worked great. They should all interchange.

 

Any '74 to '92(NA) starter will work, regardless of tooth count. The FC starters need the long bolt they come with.

People ask this type of question fairly often.

 

sorry jeff..... I did some searching but didnt seem to find anything........ greta info guys and thanks so much! I think I'm gonna get the 13 tooth because it said it was more powerful.....

 

Well I've certainly answered these types of questions often enough. heh.

 

well how about this one...... it doesnt work. it turns it over fine and meshes good but it will not start it. I tried rollong the engine over manually via the alt. and it was still kicked into the flywheel and as soon as i turned in clockwise just a smidge the drive kicked back out. So it's sticking in the flywheel and wont let the engine spin any faster than the starter....... I got the 12 tooth gear reduction.

 

I've always found the FC starters spin the 12A too slow to start it.

 

Soooo. what would be a good way to make a 12a spin faster?

 

What?! they're gear reducted! they spin faster than 12a starters!

 

So does anyone know why it isnt working?????

 

could it just be a bad new starter? it happens

 

I just made a post about it.

FC starter running my '82 12a. Works like a champ and way better than the stocker.

Think the FC starter ended up being a 12 tooth. No funny starter/mesh sounds either.

 

So maybe some fine sanding of the teeth? Maybe theyre too tight and not allowing a smooth disconnection?

 

You got this sorted out? I would like to know

 

Nope I was waiting on some suggestions....... lol Im just as curious as you!

 

I think it's because the smaller diameter flywheel on your 12a. i was just going through starters, i had one off of the engine that's in my car now, a 13B that i don't know for sure if has 74-75 housing and no idea what rotors, or maybe 84-85 housings. The starter on it has a completely different armature in it, different diameter, and my 12a starter from my old engine has 2 ground brushes, where the 13b has 2 fields and 1 ground. There was no way to combine the two starters though because the armatures were different diameters so the brushes didn't make contact. A gear reduction isn't good when you need rpm like the rotary does. I was having starting problems and with my battery voltage down to 12.4 volts, it wouldn't spin fast enough to get compression. With a jump, compression jump right up and i was able to get it running. Could you give me the part numbers for the 12 and 13 tooth starters?

 

WOW man...... lol its been a while since ive been on here! lol Ill get back to you with the numbers man......

 

I guess I have a small update I can add to this thread. I found an FC starter in a box. I'm going to hook up a battery to watch it spin. If it jumps out, spins well and pops back in like it should, I'll test it in something. Probably a 74 bellhousing just for fun/just because I can.

 

Would like to know as well!

 

It sounds like it should not work, but it does.

I've used just about every possible combination of engine, transmission, and starter in the year range '79-92. They all work together as long as they are nonturbo manual trans. Automatic is different and turbo is different.

 

Yep. Different tooth counts, but they all work.

I just tested ten starters and eight turned out to be good.

 

All N/A RX-7 have the same diameter flywheel.