Mariner inline 90 hp or 115 hp, and model year?

I have a Mariner outboard but there are no decals on the engine, since it is painted. I am therefore unsure if it is a 90 hp or 115 hp engine.

Also i have trouble finding what year model it is. I think it is a 1987 model.

The serial number is 0B11800, and the last number i believe is 4. But it might also be 9. It is difficult to find out what number it is, since the engine har been painted.

Would appreciate if someone could help me.

Robert

Either number at the end is coming up the same which is a MERCURY INTL 90 HP ELPTO 3 cylinder Model Number 1091727 which makes it out to be a 1987 engine year. http://www.boats.net/parts/search/Merc/Mercury/1987/1091727/parts.html http://www.marineengine.com/parts/mercury_marine_parts/sn/0B118009

What I don`t understand is that the engine is 6 inline cylinders. Why does it make out to be 3 cylinders when I look at the boats.net parts link?

When i check at this site : http://www.maxrules.com/models/Merc_model_files/115-150.html

I get the above? Can you figure that out?

Agreed, when I look this up it is a 1987 model 115 hp.---------Remove high speed jet and confirm with jet size.

I might be asking a very stupid question, but were is the high speed jet located and what size should it be for a 115 hp?

You might have a "franken-outboard" on your hands.

Where are you seeing the "serial number".

Look for a model number or casting number on your carb(s) - that may narrow down at least what the powerhead is.

The serial number you posted 0B11800? is recognized by the programed computer system as being a Mercury engine model not a Mariner. Typically if the engine was a Mariner, it would come up as one which also shows the HP as well. I used 3 or 4 different sites and they all came up the same as posted.

A few thoughts would be either the serial number was read/posted incorrectly, there could be two different serial numbers in different areas such as on the transom plate assembly on the outside of the boat along with another number found on one of the power heads welch/core plugs that is typically stamped into one of them for hidden ID's. Maybe somewhere along the line the engine power head and outboard assembly was changed/swapped around as that happens often.

Just in case, here's an image of a serial number stamped into a welch plug for you to compare, https://www.perfprotech.com/blog/ma...ry-marine-outboard-motor-serial-number-number

Can you take a close up photo of the serial number/s you find along with some overall photos of the engine as sometimes that may help too.

Using the first serial number 0B106928 you found from Maxrules, it comes up as an inline 6 "MERCURY" 115 ELPTO from 1987. Here are some parts links that you could use for it.
https://www.perfprotech.com/mercury-marine-parts-catalog/umodel/15757
http://www.marineengine.com/parts/mercury_marine_parts/sn/B106928
http://www.boats.net/parts/search/Merc/Mercury/1987/1115727/parts.html

Using this chart in the following link under the "Mariner" look up section under both 90 and 115 HP, it would show the inline 6 engines to be an 1986.
http://www.autorepairmanuals.biz/page/608079
90 A954612 - B167518 1986
115 A941218 - B167870 1986

And under the "Mercury" engine brand/name it shows 1986 for both inline 6 cyl - HP's.
90 A902436 - B110053 1986 = https://www.perfprotech.com/mercury-marine-parts-catalog/searchserial?search=A902436
115 A907777 - B110053 1986
http://www.autorepairmanuals.biz/page/609774

Another way to try and find out what HP you may really have is to try and find some numbers on the carburetors and compare them to the said HP in either/or both parts guides and/or service manuals.

This is not easy. Below is a picture of the serial number. I believe the last number is 4.

On the carb float casting is a stamped in number. It will be WMK-XX. what are the 2 numbers where XX is as this will tell if 90 or 115 as they use different series of carb. WMK-23, 27, 30, 35, 39 are 9ohp