midnight mechanic

recently the 8 y o atkins rebuild has had trouble starting, it smokes heavily and misses. Sometimes I have to remove the plugs, clean them with solvent, and turn the engine over w/o the plugs to blow out what ever is causing the problem.

I can see that the plugs have good spark. Now when I "deflood" this way, the engine starts to sound like it is firing, then it goes back to not firing. I removed the plugs and they look like their getting wet after one revolution of attempting to start the engine.

My theory (oh boy here goes!), is that oil or coolant is leaking into the firing chamber. Only hope is to get lucky with some "fix a leak stopper". Atkins 12 a rebuilds are at least $4000 now. Good 12a housings are a collector's item.

So is this then end of my 22 year rx-7 affair?

rwatson5651

iTrader: (5)

Shouldnt be, if all else fails, you can put together a 13 B built with 12 A irons more cheaply. If you wanted to keep the Niki you could use an adapter to bolt the 12a intake to the 13 b so it would be "stock appearing".

DreamInRotary

iTrader: (49)

I'd just look into getting a 13b as they are more common, more power, and easier to get parts for now.

midnight mechanic

totally pissed off, I poured a pint of methanol (Heet, dry gas) down the carb. After some hesitation , the damn engine started up. Smoking heavily with liquid was shooting out of the exhaust.

While driving at 50 mph, putting it in neutral, I shut off the ignition, and restarted it w/o any problem. Now my theory (here we go again), is that the methanol/heet/dry gas cleaned out the combustion chambers.

Later, I put Bardahl's stop smoke in the oil.

On the 13b thing, you say I can use the nikki carb on it? Is Rotary Planet any good? 12a's go for $1700 there.

flight_of_pain

We can rebuild it, we have the technology...



In all seriousness, go for a 13b, or build a 4-port 13b using 12a irons and -se rotating parts.

Isaac

2stroke1971

I just went through a spell of white smoke and hard starting and missing on our '85 12A....
I tried putting some alumaseal in the radiator as is listed in the archive section and it took a day but it stopped all together, the miss went away and it idles nice again. On ours, i guess it was letting coolant into the combustion chamber but the sealer took care of it. Its got 224,000 miles on it, its a shame the rubber seals give out before the apex units. Its not a fix exactly, but it will keep ours alive a little longer.

Cookboy

iTrader: (10)

Alumaseal rocks!

t_g_farrell

iTrader: (1)

How many miles are on the rebuild?

Is hard to start cold or hot?

I wouldn't jump to a rebuild just yet. You may have simpler issues that need to be addressed.

midnight mechanic

~30,000 miles on the rebuild, hard to cold start, runs on one or two chambers for a minute, and smokes like a dragon for a few minutes, then it is fine.

I put STP stop leak in the oil which didn't address the problem. In a differnet lifetime the STP stop leak stopped oil leaking to the outside. Added Bardahl (I loved the Miss Bardahl unlimited hydroplane) stop smoke and leak. It seems to be better now.

And it is pale grey smoke, not black, and not white.

midnight mechanic

New plugs fixed the problem!!!

Also replaced the dist rotor, dist cap, plug wires, and alt fan belt. Also I added Alumi seal to the coolant and Bardahl Stop Smoke to the engine oil.

I'm so happy that I have to change my underwear now.

sbeers

I might try this onmy 79 if i can get it running agin

Cookboy

iTrader: (10)

That is a mighty good feeling!

Adam12A

Everyone always says it's the end but it never is

DivinDriver

iTrader: (15)

Rotaries need new plugs at very short intervals compared to modern cars; Owner's manual says every 30k miles. I never let mine go more than 20k no matter what.

There's no scheduled cycle on the cap and rotor, but once you start seeing blistering/oxidation on the arc contacts or any carbon tracing, you either have to carefully clean that up if it's not severe, or replace them. Especially on the newer caps that have aluminum contacts - -they get white oxidation deposits that are highly resistive and greatly decrease delivered power.

NCross

iTrader: (18)

Why is that a shame? Thats a good thing. The hard seals would destroy your housings and plates which are much more expensive, and rare for mint examples.


To the OP. I would use White Shepard oil stop leak. It worked for my old FC. It gave it another 4000 miles of smoke free driving before it started again. It is a seal sweller... so you want to change the oil after a couple hundred miles with it in the pan. An often over looked problem causing white smoke on a 12a is the intake manifold O rings. Replace them and the manifold gasket. I guarantee it will help at least a little. My old 79 came with a modified intake that had the coolant seals JB Welded. It eventually cracked and allowed coolant into the manifold.