How many spark plugs can I expect to foul after decarbonization?
 

Next week is my spring break, so that gives me time to wok on the mazda, i've been just working on the weekends. My first engine(in an 81) dislodged an apex seal, so i bought a parts car (83) for the engine, but it was carbon locked. I did the treatment with the ATF and it freed up. In the meantime, we also removed the rats nest. Now that we have the engine from the 83, in the 81 it won't start. I've gone through 3 sets of plugs, all fouled. I took the last set out, and it was filled with atf and gas. I took all the plugs out and turned it over a few times to see if i could blow a lot out, but still not luck. I'm getting a new set on my way home today. Any suggestions, i don't want to resort to trying to pull it off. thanks.

do a compression test. make sure you have a strong batterie. before trying to start it again make sure you have spark to all 4 plugs. make sure your timing is correct. youre obviously getting fuel so thats not an issue.

If those are new plugs, clean them. If they are old plugs, clean them, lol. I sandblast, spray down with brake cleaner, then blow dry with compressed air, good as new, repeat as needed. If you don't have a sand/bead blaster, the brake cleaner will work too, it doesn't remove built up carbon by itself very well though.

I found that if you use Seafoam for deflooding you won't foul plugs. The stuff will actually clean them up for you while deflooding the engine. Freebie!

You sound like an infomercial for them. Do they sponser your autocross events?

I wish I had a sponsor! :) Really though, if I find something that really works then I don't hesitate to let people know if I think they could benefit from it as well.

I wouldn't use ATF in any engine.