3.0LX InlineMercruiser, slipping

[olddogmike]

I have a 3.0 LX mercruiser inlione 4 cyl with a Alpha 1 outdrive unit. The boat will make way up about 2000 rpm, after that the rpm's go up and speed falls off. The wheel hub is brand new. I don't smell rubber burning but I have never let the engine continue to run after the rpm's begin to climb. I was told that it sounds like the engine coupler so I pulled the engine and flywheel cover and removed the coupler. It is a triangle coupler for a 12 and 1/2 inch flywheel. I will be ordering the new coupler on Monday. The thing that is bothering me is that the old coupler does not look to be damaged. There appears to be no visible rubber damage. If this turns out to not be the coupler then where should I look next for this problem? Thanks to all on the board for any help you could give me.

 

[Don S]

Re: 3.0LX InlineMercruiser, slipping

Prop hub would be the only other place for slipping. Either find a different prop, or have the one you have rechecked.<br />If it was just jumping out of gear because of drive or cable, you would hear some clanking and banging.

 

[craze1cars]

Re: 3.0LX InlineMercruiser, slipping

I'm no pro here, but are you sure something is actually slipping? Could you be drawing some air bubbles into the prop, causing it to lose bite? I believe it's called ventilation...someone correct me if I'm wrong.<br /><br />Have your exhaust bellows come loose? If so I would imagine it's possible your exhaust is blowing air into the prop.

 

[olddogmike]

Re: 3.0LX InlineMercruiser, slipping

Thanks craze1cars, but cavitation has been ruled out. Bellows are in shipshape. I will be replacing the coupler by mid-week and hope to have the boat back in the water by next Sat. Rockfish season opened today here in Maryland and I'm really looking to get back on the water. Thanks for the posting. I wonder if the lubricant in the outdrive could have anything to do with the problem?

 

[olddogmike]

Re: 3.0LX InlineMercruiser, slipping

DON S; THANKS FOR TAKING THE TIME IN REPLYING TO MY QUESTION. I WILL BE INSTALLING THE NEW COUPLER THIS WEEK AND WILL GO TO SEA TRIALS AS SOON AS THIS IS DONE. I WILL LET YOU KNOW HOW THIS WORKS OUT.<br />ONCE AGAIN THANKS TO YOU AND ALL WHO RESPOND TO THIS FORUM. <br />MIKE.

 

[Don S]

Re: 3.0LX InlineMercruiser, slipping

I wonder if the lubricant in the outdrive could have anything to do with the problem

Nope, gearlube won't cause your problem, but when you put it back together make sure the alignment is dead on, then turn the engine half a turn and try it again. To make sure the new coupling is ok. I have found many of them that aren't.