I have a UK 1994 Mk1 on 21,500 miles, which I have owned since 2014.
It had a cam belt change as part of a Mazda “54k” miles service in 2007 on 10,800 miles.
So it was replaced after 13 years!, which coincidently is now 13 years ago.
? what is the opinion on an aged related replacement, or, take a chance on low mileage/usage.
Taking a chance means taking a chance that if the belt snaps at 70 in the outside lane, you have the time and sense to drift safely to the hard shoulder. The engines are “non-interferance”, but I’m not sure if the belt gives way while the engine is bouncing off the rev limiter, something is not going to interfere. At the very least, you ought to inspect the belt for any sign of oil contamination, from a leaking camcover seal etc. Presuming the camcover was also changed 13 years ago, you could also take a chance on that.
I read somewhere when we were looking to change ours that Manufacturers guarantee you change after 7 years regardless of mileage citing deterioation, but they would wouldn’t they 
I would say that 13 years is a good stint and probably worth the investment, and peace of mind, in changing. We did ours ourselves and it wasn’t too difficult a job, maybe check the water pump at the same time?
I think something to look at this winter, although I’m not that experienced or confident when I read of the snags.
I see MX5 parts has a tutorial so lots of reading first, specialist tools?.
In the meantime will avoid outside lane of motorways, which I do anyway!.
We just bought a cam lock but nothing else. There are lots of youtubes and different techniques 
Personally I’d get the waterpump & belt done if for nothing else, peace of mind first, followed by road safety. Only other thing then to (not) “worry” about is the oil pump which has rarely been known to fail.
So saying, I had my wife’s 2002 Sport done as above but amazingly at 72,000 miles, the original was barely distinguishable from the new Gates belt…just a slightly different shade of black. Changed my Mk1 belt & pump a few years back as a precaution on a 60k replacement engine while it was still on the pallet, and it was the same with the belt, but the water pump was definately tired.
Just an insurance policy in my view for piece of mind…and note the North American Miata’s have a 100,000 mile belt change regime. Oddly.
As an aside or footnote, US market Miatas of that era had a 60,000 mile change interval, except “for vehicles sold inside California and Massachusetts”. California has a 105,000 mile state law for emissions related equipment, which includes timing belts, but only for some years.
When the 1990 Miata was launched in 1989, there was no such law, so all Miatas had a change at 60k miles. In 1993 (MY), California cars now had a 105k mile change. By 1997, Massachusetts was added.
Confusingly, it reverted back to 60k miles for 2003 and 2005, before being reinstated in 2005.
Luckily, for Mazda, the distinction is moot. Its the same belt, 60k or 105k. For other makers, they actually fitted cars with different specced belts, so there was a California timing belt and a Federal timing belt. Presumabl, one was better than the other.
Also, for California cars, Mazda added in belt inspection intervals at 60k and 95k. I’m assuming every time there was an inspection, there was a charge for a new camcover gasket etc.
Thank you for that SAZ…inspection is important.
It right to say its a peace of mind job as much as safety, I could always paint the cam cover if nothing else, but originality!!.
It came to mind as I just had the seal go in the slave cylinder which left me with a tricky 3 mile home journey with a dodgy clutch. I took this job on as thought its just 2 bolts, fluid connection and a bleed nipple, I was stuck at home anyway so why not.
I researched timing belt and water pump change and if done methodically my skills might get me by, till I cant get the crank bolt off!!.
Anyway the service kits are in short supply unless you get genuine Mazda kit from MX5 parts at twice the price…? good investment for a novice.
Thanks for your input, looking like an autumn/winter job.
I just spoke to Andrew at Autolink in Dumfries on your behalf.
01556 509088
If your car is an 1840cc, he has your bits.
We all deal with Andrew and have done for many years.
Fair on prices and prompt deliveries allowing for Cov-id Royal Mail backlogging.
thank you…I will take a look at it and get a new cam cover gasket first…more in the autumn/winter.
It would be interesting to see what would fail first over time and mileage, timing belt or waterpump. From my experience it would probably be a close call with the waterpump being the more likely failure point.
Whatever anyone tells you, this is usually not an easy job, so for most worth the £200+ paid to another to avoid all the hassle.
Done this job several times and will do it again but being honest £250 to have this work done with no collateral damage/other issues is possibly money well spent.
When I did this job on my 1997 MK1 1,6, three cam cover bolts snapped and I decided to replace the crank and cam seals as well as the coolant hoses…apart from heater hoses; chickened out of those.
Right of passage job that is achievable but don’t expect an easy ride. At least if you do it yourself, possibly with some help/advice you will know it has been done properly and any other required work completed with cleaning done. Professionals will have to side step some of this peripheral work.