head gasket/ power loss

[fish4rob]

For whatever reason, when I tighten the bolts that go tp the head, I am unable to start my boat. If I back off the screws it will start fine. Any idea what is going on. I tightened the head down without a gasket and was able to turn the flywheel pretty easily. When I put the gasket in, I can still turn the flywheel, but it takes a lot more pressure. This is on a 97 Force 75 hp.

 

[steelespike]

Re: head gasket/ power loss

Did you mean the starter can't turn the motor with the bolts tightened?
Or it won't run?
Try turning with the plugs out. You should be able to turn by hand with the plugs out and the head bolts torqued.If it is harder to turn after torqueing
with the plugs out something is screwy.What torque are you using?
Why did you have it apart?What repair was done?

 

[fish4rob]

Re: head gasket/ power loss

Thanks for reply. I had the head off because from time to time debris gets in the water jackets. Don't know why, but this particular model never has had a strong water stream. I pull it every now and then to get any debris out. When I torque down the bolts, the flywheel will barely spin. If I take the pressure off, it will spin as if nothing were ever wrong. I took it to the shop today and they should get back to me in a week or so. I was just wanting to know if anyone had an idea of what the problem was. Thanks.

Rob

 

[steelespike]

Re: head gasket/ power loss

My guess is that somehow the head bolts are distorting the block.

 

[Frank Acampora]

Re: head gasket/ power loss

Consider that you might have hidden corrosion on the battery terminals and the starter is not getting full voltage. Also consider that the srarter may have worn brushes or an open winding on the armature not allowing it to develop full power. Thus, It can not crank over the engine when under full compression. When you loosen the bolts, a little compression leaks--just enough so it can crank.

Do the easiest first: Check the battery connections AND the GROUND on the block. Then troubleshoot the starter motor.

 

[MercFan]

Re: head gasket/ power loss

Latching onto Frank's post.
Do a compression check with the bolts loose, and again with the bolts tightened. With all plugs removed the starter shouldn't have any trouble turning the engine either way.

What are the chances of a busted fuel pump and the engine hydro-locking on fuel?

 

[steelespike]

Re: head gasket/ power loss

Consider that you might have hidden corrosion on the battery terminals and the starter is not getting full voltage. Also consider that the srarter may have worn brushes or an open winding on the armature not allowing it to develop full power. Thus, It can not crank over the engine when under full compression. When you loosen the bolts, a little compression leaks--just enough so it can crank.

Do the easiest first: Check the battery connections AND the GROUND on the block. Then troubleshoot the starter motor.

Frank I'm pretty sure he is saying (with the plugs out) when he tightens the head bolts it become hard to turn by hand.Obviously should be no difference.
really strange??