Hypothetically Speaking...what if I did turn the engine COUNTER-clockwise??

[Dances_With_Wiener_Dogs]

I didn't do this, but as I'm turning the engine over via the lower alt belt pulley, the manual says to turn it Clockwise only. Okay, fine.

 

So what happens if I turn it anti-clockwise?

[Stan Walker]

It unscrews the crankshaft.....?

 

Stan

[Argon]

I'm guessing that the slack on the cam chains would be taken up in the wrong direction, which would make the valve adjustments off.

[ShovelStrokeEd]

Actually wouldn't effect the valve adjustments at all but could cause trouble with the cam chain tensioner(s). They really are directional in nature and you could wadd up the cam chain and do mischief to the workings. Also, due to bad valve timing, piston to valve contact might happen during the overlap. Not likely but it could happen.

 

Of course, a millwright, or competent engineer would never use those terms to describe rotation. Too much opportunity for ambiguity. You must always mention an orientation along with the direction so that its clockwise when facing the rear of the motorcycle. Better would be bottom towards you when on the right side. Since the drive shaft rotates in the same direction as the crankshaft, you would describe its rotation as up and towards the center. No orientation ambiguity there as the description does not depend on the relative position of the viewer.

 

Sorry, just feeling a little pedantic tonight.

[BMT]

Sorry, just feeling a little pedantic tonight.

Hey, being a pedant isn't against the law (yet)!

 

However, "clockwise when facing the rear of the motorcycle"? I'm now looking at my license plate ...

 

With kindest pedantry,

[ShovelStrokeEd]

See?

 

That's what I mean about the imprecision of the term. One word and your screwed. Clockwise when facing towards the rear of the motorcycle. Or Clockwise from the alternator end. Digital clocks have even messed that up.

[Dances_With_Wiener_Dogs]

The important thing is that I knew what I meant and I wasn't trying to explain to anyone that was also going to be doing it him or herself. I just get anxious whenever I see a DON"T DO IT THIS WAY in text without the corresponding reasons why.

 

I'm a why kinda guy. I'm sure it drove my parents nuts when I was a kid!

[fnyrt]

I'm sure it drove my parents nuts when I was a kid!

Why?

 

 

 

 

 

 

 

 

 

 

 

[Willie]

I would think that you run a great risk of reversing time and going back to the moment again right before you turned the motor in the opposite direction. This would lead you to get caught in an endless loop that would ultimately cause the destruction of the universe as we know it. PLEASE do not turn the motor in the opposite direction. Thank you, Terry

[PeterD]

OK I haven't read the "right" answer yet, so I'll put in my 2 cents. I don't believe any of those concerns mentioned so far are valid. I'm 99% certain the only reason is to avoid the possibility of loosening the pulley screw. Remember you are using a socket on that big screw in the middle of the crankshaft. You only want to turn CW to avoid the risk of loosening it.

[Joe Frickin' Friday]

OK I haven't read the "right" answer yet, so I'll put in my 2 cents. I don't believe any of those concerns mentioned so far are valid. I'm 99% certain the only reason is to avoid the possibility of loosening the pulley screw. Remember you are using a socket on that big screw in the middle of the crankshaft. You only want to turn CW to avoid the risk of loosening it.

 

Tightening torque spec on that pulley bolt is 50 N*m. It doesn't take nearly that much torque to turn the engine backwards.

[BMT]

It doesn't take nearly that much torque to turn the engine backwards.

Unless you've screwed the valve timing and the valve heads are jammed against the piston crown ...

 

HTH

[Joe Frickin' Friday]

It doesn't take nearly that much torque to turn the engine backwards.

Unless you've screwed the valve timing and the valve heads are jammed against the piston crown ...

 

Um, well, if that happens, then you've got far bigger problems than a loose alt pulley...

[Bob Palin]

I can at least confirm that turning it backwards doesn't automatically destroy the engine, I did it a couple of times before I learned better.