Quick question ???

[YZR500]

This subject has been cover before, and based on my research the crank pulley can be remove as follow:

The muffler with rusted nuts and bands
rear air channel
the rear sheet metal
the AC compressor
AC stand
Engine mount

Thanks to "Flat6pak"

But my question is: is the crank pulley bolt/nut standard treaded or reverse treaded ?

Thanks in advance, I just don't want to put huge torque on that bolt the wrong way and breaking it in the crankshaft. I am planing on replacing my OEM pulley with an aluminum one from Clewett Eng. " great craftmanship by the way" and renting a high torque impact wrench for $16 at my local rental tool shop to do the job.

Thank you

Stephan

[Flat6pac]

Its not a reverse thread but it has a lock on the bottom side of the head of the 17mm bolt head.
Bruce

[YZR500]

Forgive me for my ignorance Bruce, but how to go about disengage/remove this lock ??

Thanks

Stephan

[Gunter]

I think what flatpack means is the positioning-dowel that gives the pulley the right position so that the marks for setting ignition timing are correct.

You will see the dowel pin once the pulley is off.

Does the new ALU pulley have the correct timing-marks and the little hole for the dowel to match up?

Put a few drops of penetrating oil where the hex meets the case and let it soak for a minute, then try the rattle-gun. The bolt has normal right-hand thread meaning go ccw to loosen.

You may not have enough room under the bumper to position the gun with the socket onto the bolt? Maybe??

Also, the action of the impact will try to turn the engine ccw; not good. Put it in reverse gear for the shortest ratio and see how it goes.

BTW: If you're doing it to reduce momentum-effect on the engine, a lighter flywheel and ALU pressure plate (Sport clutch) would be much better.

[YZR500]

Originally Posted by Gunter

I think what flatpack means is the positioning-dowel that gives the pulley the right position so that the marks for setting ignition timing are correct.

You will see the dowel pin once the pulley is off.

Does the new ALU pulley have the correct timing-marks and the little hole for the dowel to match up?

Put a few drops of penetrating oil where the hex meets the case and let it soak for a minute, then try the rattle-gun. The bolt has normal right-hand thread meaning go ccw to loosen.

You may not have enough room under the bumper to position the gun with the socket onto the bolt? Maybe??

Also, the action of the impact will try to turn the engine ccw; not good. Put it in reverse gear for the shortest ratio and see how it goes.

BTW: If you're doing it to reduce momentum-effect on the engine, a lighter flywheel and ALU pressure plate (Sport clutch) would be much better.

Thanks Dr Gunter, appreciate the enlightenment.

The pulley has the correct markings and I now know what Flat6pac meant by locking the pulley.

Also this pulley was not fabricated to reduce rotating mass, but rather to reduce belt slippage on my supercharger. I now have a 6 rib pulley on my crank and a pulley to match on my S/C.

My OEM v-belt crank pulley was a 5", it is now 5.5" ( 6 rib) and remain 5" on the fan (alternator). This will increase the speed of my S/C and hopefully (theoretically) increase boost.