Mariner 25hp

[51ROB20]

Hi, I have been trying to find out the age of my 25hp mariner and was wandering if anyone can help me. On the plate it has:- W25 ML
648 L380525
I was told that you can work out the year of manufacture from the ser number but I must be a bit thick as I cannot see anything that resembles a year date.
Also could anybody tell me what the fuel/oil mix is for this motor as the place I got it from (was a rescue boat at a camp site on the west coast of scotland) seem to of been running it on a heavy oil mix.

[Milgrip]

Hi 51ROB20, This might help, have a look here:

How To: Outboard Engine Serial Number Year Match, iboats.com How To Library

Can't help with the fuel/oil mix though.

[Boats&Outboards]

Have another look at the plate and tell us the identity letter etched into the bottom corner. That will get you the age

Peter @ Boatsandoutboards4sale ~ askboatsandoutboards4sale@sky.com ~ 07930 421007

[9D280]

The "648" is the key. Looks like a Yam derived serial number. they used 3 digit codes for the model year.

I'd guess with a number like that it's going to be premix 50:1. A lot of places used to "add a bit more oil, just to be sure"...... If you got a filler cap on the top of the engine, it;s an auto mixing machine - post back as they may have been premixing 'coz that had broken.

Assuming it;s a premix, here's the quantities of oil to put in an empty tank before filling:

Tank size Oil "pre shot"
30L 585ml
25L 490ml
22L 430ml

[51ROB20]

Originally Posted by Boats&Outboards

Have another look at the plate and tell us the identity letter etched into the bottom corner. That will get you the age

Peter @ Boatsandoutboards4sale ~ askboatsandoutboards4sale@sky.com ~ 07930 421007

Will have another look in the morning but I did not notice anything etched in the corner when I wrote the info down

[51ROB20]

Originally Posted by 9D280

The "648" is the key. Looks like a Yam derived serial number. they used 3 digit codes for the model year.

I'd guess with a number like that it's going to be premix 50:1. A lot of places used to "add a bit more oil, just to be sure"...... If you got a filler cap on the top of the engine, it;s an auto mixing machine - post back as they may have been premixing 'coz that had broken.

Assuming it;s a premix, here's the quantities of oil to put in an empty tank before filling:

Tank size Oil "pre shot"
30L 585ml
25L 490ml
22L 430ml

Many thanks, there is no filler cap on the top of the engine. The tank that came with the boat is a 25ltr one. From what I was told by the chap that used to operate the boat for the camp site he ran it on a mix of 25 parts petrol to 1 of oil. From what you say it should be 50 to 1, so its not surprising that it smoked like a pig when I started it. At the moment I am in the middle of doing a full strip down and service, that way I know that it is not likely to blow up on me.

[51ROB20]

Originally Posted by Milgrip

Hi 51ROB20, This might help, have a look here:

How To: Outboard Engine Serial Number Year Match, iboats.com How To Library

Can't help with the fuel/oil mix though.

Many thanks, I have had a look on the iboats link but could not find any numbers on there that came close to the numbers on my motor. But they have said that they will look in their data base and get back to me.

[9D280]

Originally Posted by 51ROB20

Many thanks, there is no filler cap on the top of the engine. The tank that came with the boat is a 25ltr one. From what I was told by the chap that used to operate the boat for the camp site he ran it on a mix of 25 parts petrol to 1 of oil. From what you say it should be 50 to 1, so its not surprising that it smoked like a pig when I started it. At the moment I am in the middle of doing a full strip down and service, that way I know that it is not likely to blow up on me.

OK, it's a premix.

25:1 - that's appropriate for the first 10 hours or so of running in, then it just smokes, smells, becomes a PITA to start and reduces performance & economy!