[JDMAflac]

How difficult is it to change a waterpump?

 

[Nevadabob]

It takes a few hours.

If you can change the timing belt...you're almost there!

http://www.miata.net/garage/water_pump.html

 

[Fritch]

easy easy easy, if you can unscrew bolts then you can do this. Just make sure to clean the gasket surface well before putting the new pump on, don't want it to leak after you get it all back together...

 

[JDMAflac]

Im more weary of changing the timing belt since its out already and messing with the short nose crank. At least thats what I think crate motors come with.

 

[Nevadabob]

Can't say if your crate motor has a short nosed crank...did you buy it remaned from Mazda? If so I highly doubt it is a short nose.

If it is a short nose, you can change the timing belt without removing the bolt. You just can't change the front crank seal. Actually having the long nosed crank makes the timing belt change harder.

FWIW, I have changed the timing belt 2 times on my "old" '90 and 1 time on the "new" '90. Both have short nosed cranks and I have never found a problem.

I would advise changing the bolt and key if you do remove the bolt and generally follow the procedure at: http://www.miata.net/garage/timingbelt.html

Also, the additional information on the short nosed crank at http://www.miata.net/garage/crankshaft.html is good to use to evaluate your situation. I do think the recommendations about not using the bolt to rotate the engine are rather severe, however.

It's really not that big of a deal...