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Discussion Starter · #1 ·
Probably answering my own question, but since im not running a tach, do i need a tach thimble? i dont have one, but i do have another rotary breather valve and spring like on the other cam.

Should i just order a tach thimble?

also, how the hell do I get the rest of the tach drive off?

-Rob
 

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tach drive is REVERSE thread (LH) and the socket hasta be real skinny to get in there.....pain in the ass


far as the thimble question.......I`m not sure.......Gumby Chuck would know...... and he sells little plugs for that tach hole if yer interested......they`re killer lookin
 

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OK....after careful thought and lookin at the factory manual........


if you mean by "tach thimble" to mean the little slotted plug in the end of the exhaust cam.....then "NO"......I see no reason why you should have to have one.....the cam is basically located by the shoulder on the shaft at the points side of the engine......which would prevent the cam from sliding over into the void that was once yer tach assembly......so there would be no reason to have to have that slotted plug in the end of the cam I would think

there are no breather disc assembly and spring on the exhaust cam (tach side) which means it would be unnecessary to put one there...leave it out of the exaust cam

far as I can tell (and Chuck or somebody will correct me I hope) all you need is a PLUG for that hole in the case where the cam once was and see GumbyChuck for that
 

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yeah ythe thing on the intake cam is a breather valve porting disc...and it needs to go back on with the intake cam....sposed to be a locating pin to keep it aligned correctly
 

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caffeine said:
yeah thats what i thought, then i thought why does the inlet camshaft have a pring and thimble....but im assuming its to assist in proportioning the oil flow.
Inlet side has it because that's where the engine breathes...that thimble is your rotary breather valve.

Getting the tach drive off - 7/16 or 5/16 thinwall deep socket (can't remember exactly off the top of my head), Left hand thread...the rest is easy.

And I do have plugs to cover up that hole, for the exact reason you mentioned...nobody runs a tach on a chop / bob, and it cleans up the side of the motor nicely.
 

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Discussion Starter · #10 ·
GumbyChuck said:
tach thimble...not sure what you're referring to...got a pic?
no, but its on page 42 of the haynes manual its labeled as 37-tach drive thimble. its the little washer thing with the slot that goes on the end of the exhuast cam shaft. looks simliar to the one on the inlet shaft but no spring and only has a single slit in it.
 

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caffeine said:
no, but its on page 42 of the haynes manual its labeled as 37-tach drive thimble. its the little washer thing with the slot that goes on the end of the exhuast cam shaft. looks simliar to the one on the inlet shaft but no spring and only has a single slit in it.
Nope, don't need that unless you're running a tach.
 
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