Seeking Info

[Barry]

Greetings from a wannabe MX5 owner.

It's the 1989-91 models that are within in our budget and after viewing and
test driving a few I searched the internet for any info regarding those years
and found quite a bit of data that suggests that there can be a problem with
the crankshaft on these earlier cars.

These were North American Miatas, mind you. I was wondering how common this
problem is with the imported Eunos models we have here? I would presume the
engine components would be the same.

Apparently a different crankshaft was introduced around mid 1991. In the USA,
91 models above a certain VIN can be identified as having the later crank. Is
there any way of identifying which of the 91 cars here have the newer
crankshaft?

Would appreciate any feedback on this issue pertaining to MX5s in this
country.

Thanks in advance.

Barry.

[Trevor Henderson]

Barry, if you have a MX5 1990/1991 with vin 209447 or more you are safe,
conversely vin 209446 or less you have a smaller nose cone pulley bolt
shoulder diameter is 1.128 inches- the later model has a bolt shoulder
diameter of 1.455 inches for further details look at http://
www.miata.net/garage/crankshaft.html.
My mx5 has the small nose and hasn't got a problem.
regards Trevor Henderson.

[mx-5]

Hi Barry

I'm totally not mechanically minded so can't answer your technical question,
but all I can say is that I have a 1990 model and have had absolutely no
problems with anything like that

I've had mine for a year now so am relatively new to the mx-5 experience
compared to some of the seasoned & knowledgeable members here, but it's got to
be the best and most fun car I've ever owned.

I hope you decide to become a proud mx-5 owner - once you've got one, you won't
be able to imagine life without it

Regards
Tj


[...]

[Fletcher Blades]

My NZ New 1990 developed the worn crank key problem earlier this year at
about 160,000 km or so.

From the reading I've done on the net, I'd say the best way to avoid the

problem is to replace the crankshaft bolt with a new one, when you do your
timing belt every 100,000 km.

I also know of two other cars this has happened to (at least one of which is
a Eunos)... but I know a LOT of MX-5 owners... I wouldn't want to say it
was common, but it does happen.

Also that VIN number doesn't apply to us.. All the
Japan/Aust/NZ/rest-of-world MX-5s came from a different factory in Japan
than the US market cars, and their VIN numbers are from a different
sequence...

Fletch.