Mazda RX7 1.1 1979 for sale - what to pay attention to??

I have owned one. I bought it for the fascination, and was disappointed.

They have some quirky characteristics about stopping the engine and then restarting... If you do this, you may have to prime through the spark plug hole before you can restart. I cant remember the exact details. I finally sold mine to a racer who wanted to put a big Chevrolet V8 into it.

Added to that the rather poor gas mileage and the unusual parts and repair inconveniences, this is just an engine that presents more problems to a person like me than it is worth.

There are many fans of this combination, but I am not one of them.

I considered buying one years ago and I passed on it... one thing that I was told that is hard starting is often a sign that the engine is just slap wore out, and at least in my neck of the woods, there weren't any shops that were recommended for rebuilding a rotary engine. So if it doesn't start at the first twist of the key, you may want to consider moving on.

nate

I considered buying one years ago and I passed on it... one thing that I was told that is hard starting is often a sign that the engine is just slap wore out, and at least in my neck of the woods, there weren't any shops that were recommended for rebuilding a rotary engine. So if it doesn't start at the first twist of the key, you may want to consider moving on.

nate

******* Worn out is one issue, but there is, IIRC, a more common quirk that leads to a no-start situation at times even with engines that are not in that bad condition.

I cant trust my memory now to tell the exact story, but the OP or others can google it and find a ton of information.

"hls" wrote in news:gOednWKCH_tTPbXRnZ2dnUVZ snipped-for-privacy@giganews.com:

I owned a '74 RX-4 (early 13B) for two years, and I never once had that happen. But I did once have a muffler explode once on shutdown. Plus the exhaust was so awfully hot they gave you an exhaust-temp warning light on the dash, with the sensor being under the trunk floor. Once, the pipe did break, above the rear axle, which led to the rubber trunk mat actually /melting/. I was grateful for the warning light.

The rotary does (or did) have a serious need to have the coolant level remain proper at all times. Low coolant would set off a warning buzzer, as low coolant would wreck the rotary.

The carbed rotaries also /needed/ to to be revved, and part of the problems with the early ones was that people insisted on babying them like reciprocating engines, which loaded-up the plugs (especially with leaded gas) and caused other problems that I forget just now.

The thermal reactors on the pre-converter engines tended to crack from the extreme heat, and I remember that the twin-pipe exhaust system (one pipe exhaust, one pipe cooling-air) was dealer-only and was very expensive.

That is very true. I got 19 mpg. At best.

The original engines were a real problem. They go maybe 80,000 miles, then the jury's out whether they'll seize solid or not. Mine seized. They did NOT just fail gradually, over a long period of time, like reciprocating engines do.

My understanding is that they fixed most of the reliability and durability problems by the mid-'80s, and recent rotaries will see over

200K without issues.

It was a wonderfully amazing engine in 1979, comparing it to contemporary 4-cylinders. These days it's sort of unremarkable except for its smoothness and novelty. I guess the primary selling point now is its novelty and exclusivity.

For those who are OK with the foibles of the older engines, they're really interesting engines to own.

"hls" wrote in news:7PadnR5AsubvI7XRnZ2dnUVZ snipped-for-privacy@giganews.com:

Accidentally swapping leading for trailing plugs can cause that. Once you do get it started, you'll wonder why power is so low...until you discover your mistake and switch the wires around properly.

That is a good comment, but is not what I was referring to. Seems to me that if you pull into a parking space and cut off the engine abruptly, you may have a secondary problem of starting. And the solution is to take out a plug and prime the cavity with fuel.

Well, that's not really a solution but will get you on the road again. Happened to me and to a friend who had a younger RX than I had.

"hls" wrote in news:iradnSfHOp_jpLTRnZ2dnUVZ snipped-for-privacy@giganews.com:

Never happened to me once during the ~20,000 miles I covered in that RX-

1. Maybe to you, but not to me.

My 13B had a 4-barrel Hitachi carburetor that worked on identical principles to all other carburetors of the period. Since it had your standard power-piston, all you needed to do if adequate fuel-delivery was a problem was to pump the gas pedal a few times before cranking, just like with /any/ other carbureted car of the period.

Besides, your method only primes /one/ chamber of /one/ rotor. Remember that the Mazda rotary has two rotors and six chambers. You'd have to get awfully lucky to prime that one chamber that was heading for TDC, and not the one that was already past TDC and headed for the exhaust port. Each chamber is completely sealed from all the others, remember; it's /not/ like a reciprocating engine.

Then you guys had a carb problem of some kind.

Here is a link with lots of info on RX-7's:

aqmenu.html#FCF

The not fully warmed up hard-to-restart problem is with fuel-injected engines, not carbureted ones. When you shut it off if not fully warmed up on a colder day, fuel leaks through the injectors and floods the motor. I have a 1988 GXL, and this has happened 2 times in the 22 years I've owned it. I found that putting Marvel Mystery oil in the fuel at about twice the recommended amount a few times a year has alleviated this problem for me.

>

I would have thought that flooding the rotary would be tough and excess gas would be just blown out the exhaust port. The carb rotaries that I had sure did have a lot of backfiring though. Try explaining that to the prospective buyer who's checking out the car, they'll always think you're lying.

Revving up the engine and then turning off the ignition was a mistake that I only did once - the resulting explosion pretty much cured me of that behavior. I used to disconnect the vacuum throttle thingie that kept it open on deceleration and found the little pop-pop noises to be rather pleasant. I loved my rotaries but perhaps their time has passed.

dsi1 that to the prospective buyer who's checking out the car, they'll

That's basically how my muffler exploded. Except my incident involved apparently inappropriate use of the choke on shutdown.

Maybe it never really was "their time"...

BWAHAHAHAHA! Did you ever get the stain off the seat? ;)

I used to work for Coca-Cola in the summer, and they'd send us out two or three to a truck. One morning we were going along and the driver had it in high gear and the rear axle on high range, and he shut the engine off. We got right up alongside this really cute young lady waiting for the bus, and he hit the key! I think when she made the 15' leap into the air she left her panties at ground level! ;)

"dsi1" >

>>

My friend's was not of this generation, and it happened to her as well. But that could have been another thing. She had raced in from the airport, IIRC, stopped the car, and had to have the mechanics drag it in to the shop. By what she said, it was this kind of problem.

Mine was definitely a second generation with fuel injection. It only did it to me once.

I have done that key off, POW! a few times before too, when I used to own a 1962 Ford Falcon, after I had removed the old rusted out muffler and before I put a new muffler on there.It is fun, but not good for the engine. cuhulin

Teenaged boys around here used to install a sparkplug in the tailpipe, and to impress the girls (or something) they would turn off the key and coast allowing raw gas to enter the pipe, then switch back on resulting in a backfire and a flame coming out the tailpipe.

Idle minds are the devil's playhouse.

I never heard of the spark plug in the tail pipe gag before, sounds like a good one. cuhulin

I don't think you need a spark plug in the tailpipe for that to work? In order to make that work you need a car with carburetor. With fuel injection it won't get the gas into the exhaust.

-jim

That sure would mess up a Catalytic converter, wouldn't it? cuhulin

You're probably right. Well, I had my time with them and it was a gas - luckily gas wasn't as expensive as it is now. :-)

dsi1