Topic: Crankshaft rotation

[devriems]

I know that this answer has to be on the forum somewhere, but I'm not having any luck finding it.  For a CB750 K5, which direction does the crankshaft rotate?  Clockwise, I think.  Could somebody confirm?  Also, what damage can occur if it is rotation in the opposite direction.  Thanks in advance.

[Gordon]

Looking at the points plate (right side), the crankshaft rotates clockwise.  You won't damage anything by rotating it backwards, though. 

[gane]

Respecfully disagree w/ rotating crank backwards. If cam chain is loose due to wear/lack of adjustment is possible to jump time.(and that's why your' there right?)  When turned ccw.. The sohc 750 crank rotates clockwise as noted  viewed from advance unit, on other models (or indeed this) simply prod kickstarter  & note direction. luck G

[TwoTired]

The crankshaft turns in the same direction as the wheels do.

[Gordon]

Respecfully disagree w/ rotating crank backwards. If cam chain is loose due to wear/lack of adjustment is possible to jump time.(and that's why your' there right?) 

Okay, I'll concede that it may be possible to do that, but on all the sohc4's I've owned or worked on, in probably the hundred or so times I've done it, rotating the crank backwards has caused absolutely no problems.   

[MCRider]

Respecfully disagree w/ rotating crank backwards. If cam chain is loose due to wear/lack of adjustment is possible to jump time.(and that's why your' there right?) 

Okay, I'll concede that it may be possible to do that, but on all the sohc4's I've owned or worked on, in probably the hundred or so times I've done it, rotating the crank backwards has caused absolutely no problems.   

Yeah, that may be true. But if it is, any cam chain worn that much will warrant immediate replacement, so jumping time is the least of the worries.

At least I think so...

I too have never had a problem rotating it backwards for service purposes.

[TwoTired]

I too have never had a problem rotating it backwards for service purposes.

Same experience here.

[paulages]

Respecfully disagree w/ rotating crank backwards. If cam chain is loose due to wear/lack of adjustment is possible to jump time.(and that's why your' there right?)  When turned ccw.. The sohc 750 crank rotates clockwise as noted  viewed from advance unit, on other models (or indeed this) simply prod kickstarter  & note direction. luck G

i'll have to respectfully disagree with you here...  the cam chain slack will effect valve timing a little while turning backwards, but on these bikes the ignition timing is set off of the crank, making the cam chain relatively irrelevant while hand-turning the engine. as long as you're not timing the cam while turning the engine backwards, it won't matter and there are no reciprocating parts that can be damaged by doing so. it does matter that the points make good contact and are grounding when the points cam opens them, which makes proper rotational direction important.

on a CB350 twin for example, it is very important to have tension on the cam chain when setting ignition timing, as the points assembly is on the end of the camshaft.

[Spanner 1]

Non issue, +1 with previous posters.....crank and cam are 'lock-step' with each other...is that any help ??

[devriems]

Thanks for the responses guys.  This is my first time tearing into this engine, or any other for that matter.  I appreciate all the help I've gotten on this forum.