Mariner 115HP

[kenmyfam]

Buddy of mine asked me to take a look at an outfit for him while he is away at the cottage. Trouble is I know next to nothing about Mercury / Mariner motors. I will be taking a proper look at it this afternoon but in the meantime would like to do a little research on the motor.
It is a Mariner 115hp. Hood looks tall enough for it to be an in line 6 cylinder. Serial # I found on the transom bracket is 0D106728
Any info on it's year and any known issues with these motors (other than the usual buying a used outboard checks) would be very much appreciated.
Thank You,
Ken.

 

[jeswans]

Re: Mariner 115HP

These engines had a problem with the splines in the base of the crank wearing. When this happened the driveshaft would not engage. The only fix was to replace the crank. An expensive repair.

 

[kenmyfam]

Re: Mariner 115HP

Thanks for the info. Much appreciated.

 

[Barnacle_Bill]

Re: Mariner 115HP

Its a 1992.

 

[Chris1956]

Re: Mariner 115HP

Ken, If that is an inline six, I have never heard that Merc had an issue with the crank splines wearing. That motor has been made, with minor changes since the sixties.

Isn't a '92 an inline four, possibly 2+2?

 

[kenmyfam]

Re: Mariner 115HP

Actually going to check it out with the lid off tomorrow. Will let you know.
Thanks for the info,
Ken.

 

[jeswans]

Re: Mariner 115HP

Chris 1956,

I know two no including my own that had this problem with the crank splines. A friend who is a Merc certifed mechanic also told me this is a common problem with salt water usage. Not sure where you are located, as this may be contributing to your experience.

John

 

[Chris1956]

Re: Mariner 115HP

John, The earlier 70s inline motors had mild steel driveshafts. If the splines on these were ungreases whne maintenance was performed, they would corrode into the crank splines. The later 70s driveshafts were stainless. For the most part these did not corrode to the crank. Now you could ruin the splines on the crank, if you did not install the gearcase properly, but that was not the fault of the design.

I never heard of cronic splines stripping on the old inlines. My '77 Merc 1500 was used in saltwater until it thru a rod last year. The crank splines are fine.

 

[jeswans]

Re: Mariner 115HP

The engines that I am aware of that had the spline issue were 1978 and newer. I agreee with what you are stating regarding the mtce and grease. The crank in mine was not stainless, and my engine was a late 1979 production unit.

 

[Chris1956]

Re: Mariner 115HP

Crankshafts are never stainless steel. They need to be cast iron, since that is how they are made.