air pocket ?

[rwcreigh1]

hello,my father in law has a 1984 thunderbird with a 90 hp rude 1985.when we go out it runs fine but every now and then it feels like it gets a pocket of air under the engine.it runs a little high(just for a second)then goes.he has only had it for 1 year and only took it out maybe 4 times so he dont really know it that well.what do you think it might be.i know it sounds crazy about it getting air pockets but that is what it feels like.thanks richard

 

[JB]

Re: air pocket ?

Howdy Richard.<br /><br />You may have a spun prop. Mark the joint where the metal and the soft hub meet. Take her out and run her until the rev-up happens, then check the mark to see if the prop and hub are still in the same alignment. Rehubbing the prop is reasonably priced.<br /><br />You might also inspect the prop blade edges for damage that could be causing occasional cavitation. Prop reconditioning would be in order. There are also some excellent deals on new props here at iboats.<br /><br />If the problem happens more at high speed, when in a chop or when turning the prop might be ventilating. Check the alignment of the anti-ventilation plate with the bottom of the keel. It should be even to an inch or so above the level of the keel.<br /><br />Let us know what you find, and good luck.

 

[rwcreigh1]

Re: air pocket ?

ok we did have the prop rehubbed.thanks

 

[rwcreigh1]

Re: air pocket ?

he was thinking maybe the clutch was slipping but we dont know alot about them.

 

[Silvertip]

Re: air pocket ?

If the dog clutch were worn it would feel like you hit something in the water when this "slippage" happened. You feel a definite jerking sensation.