12a with lots of carbon
 

https://cimg2.ibsrv.net/gimg/www.rx7...acdc48d71b.jpg

https://cimg8.ibsrv.net/gimg/www.rx7...1d479fc387.jpg
https://cimg3.ibsrv.net/gimg/www.rx7...565619af81.jpg
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hi guys, i recent bought an rx7 with the 12a and it seems to have alot of carbon on the rotors (ouch) whats a good way to get rid of it without throwing the carbon against the rotor housings and scratching them? heres some pics. ive already seafoamed it with the spray and a seafoam bottle in the tank after i bought it, this is about a week later with plently of redlining. (as much as i car around here without breaking speed limits lol)

SeaFoam in the gas. There are all kinds of threads on this forum about it.

ive already done that, this is a week after. should i do it again?

Sorry - my mistake. I should have read your entire post. Rotors will have some amount of carbon. it's the seals that are the important part. It might take several applications of the SeaFoam. Try it in 1/4 of a tank.

ok, ill try that next. does this look like a particularly bad ammount of carbon? or about normal for a rotary?

Are you loosing compression? I'd be more concerned with oil delivery with all the "redlining".

I'm not losing compression as far as I know. She starts up with a hot start just fine and I got around 85 psi on both rotors and all faces today in a compression check. Not sure about the crank speed but it seemed normal. I'll try to upload a video of it tomorrow.

What about oil delivery? You mean the omp? As far as I know it's fine. How would I check it?

The factory service manual has a process for checking the flow rate of the OMP. Foxed.ca - Mazda RX-7 Manuals

None of the suggestions on these pages is an endorsement, just things I have found. Take the advise they offer knowing that unintended consequences could happen.

https://www.rx7club.com/new-member-r...emoval-924383/

https://www.rotaryresurrection.com/2...injection.html

gasoline is a hydroCARBON. the engine burns the Hydrogen, and then the Carbon is left behind. if the engine is running there will be Carbon in it, nothing to worry about, its completely normal.

I mean to the bearings, but I guess I'm more concerned for your neighbors sake. Driving around at 8k :lol:

When people talk about carbon buildup they mean build up in the parts that need to move ie seals. If you have good compression then you have nothing to worry about.

Oh .I don't drive hard near my neighbors, I try not to **** where I sleep lol. And I only get it to 7k 7.5k on accident once.

And my compression is around 85 using a regularly compression tester with the schredder driller out. It looks like that is a decent number if I go by other posts about fsm numbers. So that's good 👍

I guess I'll just seafoam it once in awhile and love her for what she is. It's too bad I can see the rotor housings either my horoscope.

So I was changing my spark plugs and found this on a rotor. I've noticed the rear rotor has alot more carbon on it than the front.
https://cimg7.ibsrv.net/gimg/www.rx7...703f3d9587.jpg

Looks like a big chunk of carbon getting ready to fall off. It's hard to tell. But this looks close to where the appex seal is.