2001 125 Merc - Looking for Info

[Robbstar]

Hi,<br />I just bought my first boat (used). The motor is a 2001 Mercury 125 HP model number 1125412YD, serial OT267832--I am looking for any background info that you can give me. In particular, I am trying to determine if this is a 2- or 4-stroke, and whether it is Yamaha designed engine. Any other info and/or opinions/advice would be greatly appreciated...<br />Robb

 

[marinegrh]

Re: 2001 125 Merc - Looking for Info

nope its a Merc, its a 2 by 4 engine though, which you may not have been told by your new best friend "The Dealer", or the guy you bought it from, anyways this means it idles on the top 2 cylinders and then about 18-2500 rpm, the bottom 2 kick in, and can throw a person into the drink if they dont know your coming up..otherwise they are great engines. and yes its a 2stroke so it needs oil like we need beer..enjoy your new found glory

 

[Robbstar]

Re: 2001 125 Merc - Looking for Info

Thanks, that explains what I experienced last weekend when I took it out. It started and ran fine, but when taking off I would throtle forward with no response, then wham, we were up and going. I was thinking that there was something sticking, but your explanation makes sense.<br />Is there any way to make that a smoother start? or will I just need to learn to finesse it.<br />Kind of disappointed in the 2 stroke, the guy I bought it from advertised it as a 4 stroke. There are no obvious markings/decals on the engine, just the 125. caveat emptor. At least I have a boat...

 

[Boatin Bob]

Re: 2001 125 Merc - Looking for Info

Nothing you can do about it the 2 + 2 on those motors, there have been several posts over the years about trying to convert them and it just won't work, big time idle problems. If you had removed the cowling you would have seen the big oil container attached to the motor (good clue for 2 stroke). By the way you need to keep a good supply of quality 2 stroke oil in there or you will be shopping for another motor.

 

[05GlastronSX]

Re: 2001 125 Merc - Looking for Info

if you dont mind me asking, how much did you pay for that engine? usually, a 4 stroke carrys a premium price especially over a carbed 2 stroke. Maybe he ment 4 cylinder but if not, thats considered false advertising.

 

[marinegrh]

Re: 2001 125 Merc - Looking for Info

Boatinbob brought up a great point, always always keep a gallon of extra tcw3 on the boat in a secure place, you have a no oil and low oil alarm that you need to make sure works, otherwise no oil in the engine no water past the prop, they tend to not like to run and hence blow up. just some past experience.

 

[Robbstar]

Re: 2001 125 Merc - Looking for Info

Thanks to all for the info and tips. I have removed the cowling and there it is, a big ol oil tank.
Here's what now concerns me: The previous owner thought it was a 4 stroke, to the point that, (based on the extra jug of oil I found in a storage hatch) he was using 4 cycle oil.
How big a problem could this be??

 

[Boatin Bob]

Re: 2001 125 Merc - Looking for Info

Well I guess some oil is better than no oil, I would think that motor would smokin more than usual. I would try and dump the rest of that oil out and put in some good quality 2 stroke. I can't believe the the PO thought it was a 4 stroke, where did he think the oil was going from the tank, didn't he wonder why he had to top it up? Man...some people just shouldn't own boats and motors.

 

[Robbstar]

Re: 2001 125 Merc - Looking for Info

Thanks Boatin Bob, There was a very small amount of the old oil in the tank, I did fill it with tcw-3 2 stroke oil. I had it out again today, and the motor performed beautifully. Funny thing, the owner's manual for the motor specifies the proper oil to use, and he had HIGHLIGHTED this!
I agree with your thoughts, and I will cross my fingers that no serious damage has been done.

Robb