Powerhead removal - 1992 200HP Mercury

[jdupree]

I just need to pull the powerhead off to replace my shift shaft & lower motor mounts. I have the Seloc manual and looks fairly straight forward. As far as linc & sync, timing, etc goes none of that should be affected? I would assume just unhook all cables from the boat and hook them back up and nothing should change? Just wanted to see who has done this and how complex is it. Thanks.

 

[jdupree]

Re: Powerhead removal - 1992 200HP Mercury

Any kind of advice, suggestions

 

[AndyL]

Re: Powerhead removal - 1992 200HP Mercury

I don't want to worry you but mine wouldn't come apart as the 4 long studs at the front were siezed big time in the exhaust plate. Tried everything from release oil to heat and they wouldn't move. Had the boat hanging off the blocks for 24 hours by the flywheel. Had to cut through the exhaust plate in the end to reduce the amount of aluminium binding them. That did it but a new exhaust plate wasn't cheap. Shame Merc don't grease them or treat them with something when they assemble the motor but then it probably wouldn't be able to be painted. If they aren't siezed in then the whole process is relatively painless and I wish you good luck. Make sure you get all the nuts off before you start trying to seperate as there are some concealed at the front end.

 

[jdupree]

Re: Powerhead removal - 1992 200HP Mercury

AndyL,

Thanks for the response. The motor I have was re-built about 2 seasons ago I was told. The powehead does look like is was removed recently. Where is the exaust plate you are talking about? Will that come into play? All I need to do is suspend the powerhead up high enough to put on a new shift shaft. Thanks.

 

[Chris1956]

Re: Powerhead removal - 1992 200HP Mercury

The powerhead is bolted to the midsection, using studs and lock nuts. The powerhead studs pass through the exhaust extension (or adaptor). Normally these are all stainsless steel, and should come out without issue. Also, the studs are screwed into the powerhead casting, and will unscrew from the block if necessary.

OK I am curious, why do you need to replace your shift shaft?

BTW - i believe you can change the lower motor mounts without removing the powerhead or LU.

 

[jdupree]

Re: Powerhead removal - 1992 200HP Mercury

Chris,

The shift shaft actually broke right where it slides onto the star fitting on the lower unit. A couple of things I was told (and think) could have contributed to this. The yoke that has the bushing in it is bad. This has caused the lower unit to have a bunch of up & down play. It would make sense because while the shaft is straight coming down from the powerhead, with the lower unit moving up and down this would cause it to bind over time. Upon inspecting the lower motor mounts, this also looks like it could be a problem.

The only way to remove the lower motor mounts and yoke to replace the bushing is to pull the powerhead. Take a look at this picture and you can see that the motor mount bolts don't have enough clearence from the leg to pull them out of the yoke. I posted the question on The Marine Doctors form and he said the power head has to come off. I wish there was a quicker fix.

 

[Chris1956]

Re: Powerhead removal - 1992 200HP Mercury

I agree that you will need to pull the powerhead to replace the shift rod. On my old inline six, you can replace the lower motor mounts by removing the dynafloat covers and the "cages" over the rubber mounts. You can then loosen the nuts behind the yoke.

BTW - my old inline had a bunch of play (maybe 3/8") in the yoke. It never caused one bit of an issue with the shift shaft. Good hunting!