Front counterweights for 12a
#1
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Front counterweights for 12a
I am assembling a 1985 12A MT but somehow the front counterweight for this engine got into a box of unidentified front weights.
And... I don't know what a 1985 weight is supposed to look like.
I have half circles, about 90 degrees and less than 90 degrees front counter weights.
Can someone help ?
With a picture maybe ?
Thanks !
And... I don't know what a 1985 weight is supposed to look like.
I have half circles, about 90 degrees and less than 90 degrees front counter weights.
Can someone help ?
With a picture maybe ?
Thanks !
#2
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http://mazdatrix.com/b5.htm
in the middle of the page there will be some info about the counter weights.
in the middle of the page there will be some info about the counter weights.
#3
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make sure you use the right one.
I had an engine that had a 12A 1982 model with the heavy rotors, manual transmission front weight (the auto one is different for this series) and a 70s model rx-4 13b rear counterweight, the car had awful vibration problems.
When I rebuilt my motor I used the correct weights for my 1885 (light 12A) rotors and it was a world better.
I paid someone hundreds of $$ for that dodgey work too 8-)
I had an engine that had a 12A 1982 model with the heavy rotors, manual transmission front weight (the auto one is different for this series) and a 70s model rx-4 13b rear counterweight, the car had awful vibration problems.
When I rebuilt my motor I used the correct weights for my 1885 (light 12A) rotors and it was a world better.
I paid someone hundreds of $$ for that dodgey work too 8-)
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Originally Posted by woodonastick
http://mazdatrix.com/b5.htm
in the middle of the page there will be some info about the counter weights.
in the middle of the page there will be some info about the counter weights.
While searching, I did find this interesting page: http://nagaracing.com/Techinfo/counterweights.htm
It looks like I can change the front weight to the 81-83 type, changing the flywheel to 81-83 at the same time.
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Mixing the 81-82 counterweight and flywheel, with the lighter 83-85 rotors is a good way to off-balance the engine.
The 76-82 12A rotors are ~.5LB heavier than the 83-85 12A rotors. This extra weight requires extra weight in the counterweights to balance the entire assembly.
Putting together an engine that shakes can really wreck the bearings, or more.
The 76-82 12A rotors are ~.5LB heavier than the 83-85 12A rotors. This extra weight requires extra weight in the counterweights to balance the entire assembly.
Putting together an engine that shakes can really wreck the bearings, or more.