115HP Mercury TOP (Tower of Power) questions

[derbsinalaska]

Hello, new here. I recently acquired a 1982 Bayliner 1600 Cobra (the closed bow one, not the bowrider) in amazing shape (no rot!!) paired with a 115hp Merc TOP. I have the serial number, but can't find any info about the year. The serial is 6128975 and the tag mentions the Brunswick Corp and Fond du Lac, Wisconsin, so that ballparks it around 1975. I've attached a picture of the motor to this post. Can anyone give me more info on it by chance? Thanks!

 

[Bobbywolf]

Your Mercury serial number puts it in "Serial Group #7" (sn 6051526 to 6262960). These were produced in 1980 & 81, if AI is to be trusted. There is a chart here that puts it at 82 (https://maxrules.com/models/Merc_model_files/115-150.php). This could very well be the original outboard to your boat.

The exact year isn't really that important, as any parts ordering is done by SN.

 

[jimmbo]

If it is an 82, that would be the yr Mercury started Prop Rating the I6, and the Serial Number would be critical for a lot of Parts
Mercury used pretty much the same Cowl Decal 1980-1983

 

[Chris1956]

The serial number (Maxrules) puts it at 1982.

The question is whether it is a derated 150HP TOP with the power ported pistons and block, or the std. 115HP TOP. If the HP is measured at the prop it could be the derated 150HP engine.

 

[jimmbo]

The 1978 1400 was a rerated/relabeled 1977 1500, because Mercury released the 150 Black Max in 78. In 79, the 140, had different Porting and Exhaust Tuning, and was no longer the inline 150. In 82 Merc Prop Rated the inline 6s, dropping the 140. However the Prop Rated Engines still had the same WOT Ranges as the Crank Rated Engines of pre 1982:
115hp: 5000-5500
90hp: 4500-5000
The 1978-1981 140hp: 5300-5800
Since the WOT Rpm Ranges didn't change with the Prop Ratings, sort of dismisses claims that the Prop Rated 115, is the Crank Rated 140, and the Prop Rated 90, is the Crank Rated 115. Parts lists also do not show that a rebadging/labeling/redecalling took place. The Number of Reeds were different too, between the Crank Rated 140, and the Prop Rated 115

 

[redneck joe]

Welcome to the forum. That motor is my holy grail.

 

[racerone]

Many of them out there running like new.-----Put a new water pump impeller in it now and every 5 years.