Merc Out Drive Problem

[robobo]

I have 4.3 merc with Alpha 1 Gen 2 outdrive. Recently completely replace upper and lower unit with new upper and lower unit. I can get 5,500 rpms from engine in neutral, however, when engaged in forward only a max of 2,000 rpms. I've checked compression of cyclinder and got 170 in each. Anyone have any ideas? Thanks.

 

[JB]

Re: Merc Out Drive Problem

Hi, Robobo.<br /><br />Welcome to iboats. <br /><br />Wrong forum. This is for Outboards.<br /><br />Moving to I/O and Inboard.

 

[skicat]

Re: Merc Out Drive Problem

First of all I would not run the engine at that high RPM's in neutral. What size boat and what pitch prop do you have?

 

[robobo]

Re: Merc Out Drive Problem

30 foot Wellcraft, twin engine, don't know pitch both are stainless steel. Never had problem with prop pitch before. thanks

 

[kcole683]

Re: Merc Out Drive Problem

Do you have the right gear ratio in the new upper unit??<br />Was it running proper rpm before the outdrive change?

 

[robobo]

Re: Merc Out Drive Problem

yes

 

[bomar76]

Re: Merc Out Drive Problem

Yes to what?<br />Right ratio?<br />or<br />Running ok RPM before?<br /><br />Sure sounds like someone installed a drive with a different ratio.......