Merc200 Mercury 20hp serial 9107078 lower unit stuck

[jeroen]

Hey all,

Bought myself a cheapo Merc 200 wich did not have spark in the first place but I managed to repair that by replacing the trigger coil. It's running quite good but does not cool. No water out of the pisser! So I thought that has to be the impeller as the motor did not run for quite a while.
Hopefully started to remove the lower gear house but it seems to hung on the shifter rod or near that area as the rest (front) drops for about half an inch. Now I soaked the shifter rod with wd-40 and hope and pray the the thing will come loose. Any other suggestions? Is there a pin in the back like is is in the front above the zink plate? Please help!

 

[JGra]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

I just finished doing the water pump on my merc 200. There was no pin or anything like that on mine. I did have to give mine a little tap to get it off. Mine is a 1968. Not sure on your serial number. I had more problems getting the impeller housing off than I did getting the lower unit off.

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

I guess it's a 76 or 77 European model. I soaked it with IMAL today again and I'm wating for to come off. The thing is stuck on the very end of the back where the shift rod and nut are placed next to eachother.
Picture is not my lower unit unfortunately!

 

[JGra]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

I could be wrong but it seems like I remember reading on the newer models there was something under the carb that had to come off. Not sure though.

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

I've looked there but cannot find any parts on the shift rod that I can loosen up. Anyone with a workshop manual wich is willing to scan the pages on the shift rod and lower unit? Thanks.

 

[ehenry]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

On the newer models the shift shaft comes all the way up to the power head and must be disconnected there. ALSO, there will be a washer that slides down the shift rod. Make sure you get it back in place or you will have shifting issues when you go back together with it.

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

Hi eHenry, ARE YOU SHURE? How to disconnect the gear that connects the shift rod with the lever? In my case it is a solid block with teeth wich is connected or glued to the shift rod. Can I disconnect this gear from the rod?
Please reply! TNX!

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

The lower unit is now open for about half an inch all the way round and is still coming down. The shift rod is splined so not in one piece! I've soaked it with WD-40 again and hope that it comes off whole tomorrow. I've been hitting on the nut but there is nothing to hit left now, any other suggetions?

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

NO MOVEMENT ANY MORE! HOW FURTER? Please help, any suggestions welcome!

 

[jeroen]

Re: Merc200 Mercury 20hp serial 9107078 lower unit stuck

I've managed to separate the lower unit from the rest of the motor by taking two steel plates from 10mm thickness and two m10 thread ends. Pushing the two plates away from eachother by bolting the thread ends.
The impeller was a piece of cake and my Merc is now pissing its guts out! Next problem is power loss when warm, any suggestions anyone?