Fan belt question....
 

Hello again 911 friends, ive got another question if yall can pls point me in the right direction...

Ive getting ready to do a valve adjustment but my fan belt is too loose to turn the engine and im going to replace the belt it might be worn because it wont tighten anymore...so I bought another 9.25x710 I believe ...so I replace it and it still wont tighten enough....question!?

1/ can I have the fan shroud in a wrong position??
2/ do I need a 10x710 fan belt?

ive tried no shims on the inner and about 5 on the outter?....

I can't believe you'd not have worse problems if your shroud were not in the right position. And it couldn't move out of position on its own. There a notch it clicks into. I just went through all this and it'd be pretty hard to put it back together the wrong way. I don't know if all 911s take the same size belt, but I know the factory belt, regardless of the dimensions printed on the belt, can be different than the aftermarket (Conti, for example) ones. You should probably remove your spark plugs to make the engine easier to turn over. Please tell me your car is in neutral when trying to turn the engine over.

I've never had to do more than move shims. If that doesn't work I would check the belt part number.

Apologies for stating the obvious but just to be clear on the basics (since I don't know the OP's experience level):
- If the belt is too loose you will have charging problems but, too tight will cause alternator problems.
- A properly tensioned fan belt will not be tight enough to turn the engine with the plugs in. I apply side pressure to the belt while turning the engine.
- Some folks suggest taking the plugs out but others feel there is danger of getting debris into the cylinders.