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Can I move the CAS back one tooth?

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Old 10-30-21, 10:15 AM
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Can I move the CAS back one tooth?

I was wondering if I can move the CAS back one tooth. I put it in according to fan, but it is really close to being maxed out. The line I had before my engine was rebuilt was somewhere in the middle, am I able to just pop it out and in, move a tooth?
i have not had the engine running yet, just checked make sure it lined up to the yellow mark while cranking the engine over.
Old 10-30-21, 10:57 AM
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You can do that, but shouldn't have to. Theoretically misaligning it one tooth should make your timing further off.

When you installed the CAS was the cap on top removed? I like to align it the gear with the little dimple on the housing, then turn it over with the cap off so I can see the gear position. Engine turned to yellow mark, then install the CAS while watching the gear to make sure it doesn't turn. Make note of which tooth is pointing at the sensor.

If it turns a bit as it slides home that's fine, just rotate it a bit until it aligns back to the tooth you noted earlier.

If it's still not centered that's fine. Gently snug the lock nut and reinstall the cap, just make sure to use a timing light to set the timing properly before you actually drive. As long as it is timing properly with the light and you are able to adjust it, I wouldn't worry.

These cars will run with the timing a fair bit out, so I think you should be able to start and idle fine.
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mazdaverx713b (10-31-21)
Old 10-30-21, 11:04 AM
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Originally Posted by WondrousBread
You can do that, but shouldn't have to. Theoretically misaligning it one tooth should make your timing further off.

When you installed the CAS was the cap on top removed? I like to align it the gear with the little dimple on the housing, then turn it over with the cap off so I can see the gear position. Engine turned to yellow mark, then install the CAS while watching the gear to make sure it doesn't turn. Make note of which tooth is pointing at the sensor.

If it turns a bit as it slides home that's fine, just rotate it a bit until it aligns back to the tooth you noted earlier.

If it's still not centered that's fine. Gently snug the lock nut and reinstall the cap, just make sure to use a timing light to set the timing properly before you actually drive. As long as it is timing properly with the light and you are able to adjust it, I wouldn't worry.

These cars will run with the timing a fair bit out, so I think you should be able to start and idle fine.
Ok, I installed it according to fan, had to wiggle it in a bit. I think my issue is I set the rotation in it without the beguine running, just cranking, because the ecu automatically advanced on cranking, that’s why I think it’s a little far over.
Old 10-30-21, 12:35 PM
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try this. its the lazy way. unscrew the CAS cover. the cover has a little plastic thing in it, and take this out. before you put the cover back on, notice that the CAS has 2 wheels in it, one with 2 teeth, and the second with um lots more (16? 28? who remembers). put the CAS cover on. rotate the engine to the Leading mark. one of the big CAS teeth should be just off center in the CAS cover hole. if it is not, move the CAS until it is. once the tooth is centered in the hole the timing will be within a couple of degrees. close enough to get it running and check for leaks and all that jazz before you get the timing light out and set it for reals
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Relisys190 (10-31-21)
Old 10-30-21, 01:01 PM
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Originally Posted by Stussy
Ok, I installed it according to fan, had to wiggle it in a bit. I think my issue is I set the rotation in it without the beguine running, just cranking, because the ecu automatically advanced on cranking, that’s why I think it’s a little far over.
It has to be idling (750rpm) and all the way warmed up to check timing.

The ECU has different timing during cranking like you mentioned, which will obscure the reading.

If you stabbed the CAS as per the FSM, you are within 2-3 degrees of correct already. And as I mentioned the car will run with the timing pretty far out. So I'd just make sure you stab it exactly as the FSM says (which is seems you've done) and leave it right there until the car runs and idles low enough to actually set it with the timing light. Don't bother with setting it while cranking because it won't be right.
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rotary_fan (10-30-21)
Old 11-06-21, 02:17 PM
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Something to note that can occur.

If you take the cover off the cas and line it up per the FSM and note that position and drop it in centered with the pulley on the correct timing mark, and you notice the pointer in the cas spins off of where it was everytime u drop it in, and requires you to crank it fully one way to get it back to the right spot.

Then it is likely the timing gear was installed backwards in the front stack of the engine when it was rebuilt, And that puts the timing off around 5 degrees or so when u stab it.

not a game over situation but u may find when setting the timing in this scenario u may need to grind the cas notch farther to get it to spin far enuf to set correctly when you use a timing light.
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