Classic 50 concerns

[MTBoat]

1. I recently aquired a boat with a approx 1989 Merc Classic 50/45, I assume it was measured at 45hp at the prop?
2. Also, there is a small black tube coming up and out of the lower unit in the front towards the transom about a foot or so, and someone plugged it...Is is important, or what is it?
3. Finally, I was planning to change the impeller, and many people said on this model its an issue or sometimes the lower unit drive shaft sticks etc....any advice on it, or a link to simple procedure. I'd like to know what I am getting into before I start if it is that difficult.
Thanks

 

[GA_Boater]

1. It's 45 HP. Whether it's at the crank or prop rated, it doesn't matter.
2. That is the tube for the speedo
3. You might have trouble getting the lower to drop if she's been in salt. Sometimes the driveshaft sticks in the crankshaft or the shift shaft sticks. Just don't get carried away with using too much force. And make sure all the bolts and nuts are removed, including the one under the anode/trim tab, that one is often forgotten.

 

[MTBoat]

Thanks, very helpful,
You know the serial number says OC133235 and I cannot find it anywhere, do you happen to know what year it is by this? I heard the first O or 0, is a placeholder, but, still I cannot find that number in Mercs info....

 

[GA_Boater]

I found this chart at MaxRules from the FAQs at the top of the Merc forum. It seems C133235 falls in the 1989 range. Check the FAQs, there are several other sites with ways to ID the year.

45 HP MODELS​
HP	Year	Model #	US Serial # Range	Canada Start Serial #
45	1986	ELPTO	A914859 - B110788
45	1986	ELO	A914859 - B110788
45	1986	MLH	A914859 - B110788
45	1986	MH	A914859 - B110788
45	1986	ELHO	A914859 - B110788
45	1987	ELO	B110789 - B238643
45	1987	ELPTO	B110789 - B238643	2880154
45	1987	ELHO	B110789 - B238643	2979679
45	1987	MH	B110789 - B238643	2979679
45	1987	MLH	B110789 - B238643	3340783
45	1987	EHO	B110789 - B238643	3340783
45	1988	ELPTO	Canadian Only	3340783
45	1988	ELO	B238644 - B393189	7006601
45	1988	ELHPTO	B238644 - B393189	7006601
45	1988	MH	B238644 - B393189	7006601
45	1988	MLH	B238644 - B393189	7006601
45	1989	MH	B393190 - UP	7032138
45	1989	ELPTO	B393190 - UP	7032138
45	1989	ELO	B393190 - UP	7032138
45	1989	MLH	B393190 - UP	7032138

 

[MTBoat]

Hmm, ok I finally get it, thanks for the chart.
I know the boat is an 89 and the motor looks like it was from the factory, so, makes sense.

 

[GA_Boater]

As far as I know the Classic 50 was only made from 86-89. 89 was the end of the model, so there isn't an ending S/N like the three prior years.

Change the impeller and go boating.