Mercury question

[baconbiscut]

Whay year was it when mercury started painting there motors black and did the mercs have weak lower units in the 60s and 70s also were the cooling systems reliable because I thought I heard they problems. Sorry for so many they don't all have to be answered in one post. Thanks for Help. Dan

 

[Chinewalker]

Re: Mercury question

1962 was the first year for an all black Merc - the 1000. Other models followed suit in 1963...

It wasn't so much that the lower units were weak on some models (small twins in particular) as it was that Mercury was late to adopt Stainless Steel for shaft material. Many Merc lower units died due to water intrusion just below the waterpump cup where water would settle and rust the upper main seal surface. The same lower unit designs lasted much better after they started using stainless in the mid 1970s...
Cooling systems worked fine, but the impellers should be changed a bit more frequently on some models - the small twins and singles had tiny impellers that seem to wear more quickly than others...
- Scott

 

[baconbiscut]

Re: Mercury question

Wow great imformation do I asked this question because in the next few weeks I'll be getting a motor from my uncle which belonged to his uncle and he only put about 12 hrs on it but. The motor is a 1965 or around there merc 200 it hasn't been used for about 10 years and its been sitting in his garage. I was wondering is there anything about this motor that would be good to know. And do you have to take off the powerhead to drop the lower unit tochange the waterpump or can I just take the lower unit off w/o removing the powerhead. Thanks Dan

 

[Chinewalker]

Re: Mercury question

Hi Dan,
It depends on exactly what year it is. If you're sure it is a 1965, then all you'd have to do is drop the lower unit. If it is an earlier model 200, it may have the notorious "automatic transmission", which can be troublesome to work on, even with the proper tools and a manual. By 1965 they had switched over to a more commonly used sliding clutch dog shifting system - much easier to handle...
- Scott