Pulley Kit Installation

Last updated: February 9, 2000

MUST READ: Mazdatrix Pulley WARNING.

I bought the Rotary Performance Race Pulley kit that replaces all of the pulleys on the car, with the exception of the airpump. They assume you will want to disconnect the airpump, and so do not include the pulley for it.

They may also make a kit that includes that pulley as well, but I didn't pay too much attention to it, since I am taking the airpump off.




  1. Loosen all of the necessary adjustment or pivot bolts to slacken the belts, and then remove the belts.

  2. Replace the pulleys.

  3. Install the new belts on the pulleys. Do not force the belt ino the grooves by prying or cranking engine.

  4. Tension the belts. Torque all bolts to the specs in the shop manual.

  5. Start the engine and run for five minutes to seat the belts. Reset the tension.

It is a good idea to recheck the tension after driving the car for a while.


Date: Mon, 08 Mar 1999 13:08:01 PST
From: "Mike Putnam"

>anyone know the tension specs for the belts for a 3rd gen?

From Page C-6 of the 94 Workshop Manual:

* Belt tension can be checked in place of belt deflection (duh!)

* Belt tension can be measured between any two pulleys.

1. Using the SST, check the belt tension.

Alternator Belt
  New 160-170 lbf
  Used 140-150 lbf
  Limit 73 lbf

P/S,A/C Belt
  New 170-190 lbf
  Used 130-140 lbf
  Limit 73 lbf

A belt that has been on a running engine for less than 5 minutes can be considered new.

2. If the tension is not within specification, adjust it.

Commentary: It's interesting that the P/S,A/C belt "new" is adjusted to a higher tension than the alternator belt, but the P/S,A/C belt "used" is adjusted to a lower tension. I'm not sure what they mean by limit, maybe that you should adjust the belts back up to specs if they drop below 73 lbf? Anyways, on my 3rd gen I adjust the "used" belt tension to 140 lbf for both belts, YMMV.


Date: Wed, 03 Mar 1999 14:14:50 PST
From: "Mike Putnam"

There has been some confusion about purchasing the belt tension gauge from NAPA Auto Parts. NAPA has a V belt tensioning tool, and a serpentine belt tension tool, you DO NOT want these, you want the V-belt tensioning GAUGE, NAPA part number KR2. This is the same Krikit II gauge that you can buy directly from the manufacture.

This gauge is suitable for measuring the tension of the third gen's wide belts. The advantage of buying it from NAPA is you get a spiffy paper sticker, with NAPA's logo, attached to the gauge at no extra cost! I recommend rotating the pocket clip attached to the gauge 180 degrees so the NAPA label is visible when the tool is in your shirt pocket protector.

Editor's note: I don't know if this will work for the aftermarket pulley kits. Take the belts in to NAPA if you are going to buy the gauge. --Steve


Date: Tue, 08 Feb 2000 19:16:41 EST
From: "Josh Stanley" (joshstanley74@hotmail.com)

The eccentric pulley is extremely difficult to remove. I used a socket with an extension of about 4 fett to get enough torque to break the bolt loose. Be careful not to break an engine mount when removing the bolt this way. If you use an air rachet, I think you need somewhere around 400 ftlbs of torque to break it loose. I only experienced slight dimming of the lights when the engine is at an idle. I have a street port, though. Idling is a bit slower and a bit lumpier than the stock setup. I think this just adds to the dimming.

From: barry

Unorthodox Racing Under-drive Pulley

i have installed one of these and am happy to pass on some tips ... yes, it's pretty easy, BUT there are a couple of pitfalls to avoid. (this is all from memory, so please forgive me if i miss a minor point here or there...)


The supplied allen bolts are _much_ to short: REPLACE THEM !!! (supplied bolts had ~ 1/8" thread engagement ... can you say "pulled threads?" being a man from the 'more threads is better' school, i cut down some 6x30mm bolts until they _just_ bottomed out ... once the sensor wheel is mounted to the hub this will give just about perfect amount of thread engagement)

Use hex head bolts, the supplied lock washers _and_ loctite for assembly (serious problems will arise if this thing ever comes loose in operation, so make sure it doesn't! buy/borrow an inch-pound torque wrench for this.)


  1. stone cold motor
  2. leave the intercooler core alone ... just remove the in/out hoses
  3. remove the entire OEM air filter box (or whatever is on your car)
  4. remove the air sep tank ... have a golf tee handy to plug the line!
  5. trans in 5th & parking brake on hard: break loose the center bolt (it's torqued down pretty well at the factory _and_ loctited ... grunt)
  6. remove both belts
  7. position the crank angle sensor (outer nipple) @ 12 o'clock high
  8. unbolt and remove the pulleys from the hub


  1. _carefully_ remove the center bolt ... (eccentric shaft press relief valve) (this is an absolutely critical piece of hardware, so treat it very, very kindly!)
  2. _carefully_ remove the hub ... mind the eccentric shaft keys on top ! (they are much less likely to fall out if they are on top ... rotate to get this...)
  3. remove the crank angle sensor wheel
  4. temporarily put the press relief valve back in finger tite to staunch the oil leak


  1. assemble the new pulley w/ sensor wheel you can have a nice lunch while the loctite sets ...


  1. install the new pulley ... IIRC, you'll have to temporarily push an a/c hard line down out of the way
  2. clean the press relief valves' washer & _carefully_ apply plenty of loctite ... torque the center bolt to 180 - 200 lb-ft (grunt) DON'T use a cheater bar!
  3. re-assemble in reverse order ...


  1. don't get in any hurry to tighten the new belts very much ... run 'em _really_ loose (love that squeal) for ~ 10 min at fast idle ... then put the belt tension gage to good use (you know, the one you bought when you bought the inch-pounds torque wrench...)

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