1989 8hp question

[Kipwrite]

I found a real nice 2-stroke, used in fresh water only, for $350. Going to have a look this weekend.

Serial number is 677-5025181

A few questions for this forum:

- this looks to be Yamaha built
- can’t tell from the serial number if this is long shaft or short shaft, or can I?
- what’s the best link to the service manual and service parts.

I’m tired of lugging around my 8hp 4-stroke Tohatsu.

It’s for an inflatable dinghy on a sailboat.

Appreciate the help. Seems like a good deal.

 

[Mohawkmtrs]

I found the following:

your motor appears to be a 1985 ( NOT 1989) Mariner Marathon (8ML) - Manual start, long shaft built by Yamaha.

Serial # Range: 677-385716 -

BTW it appears you have 1 too many digits in the serial# you posted.

Manuals/Parts should be available from you friendly Mercury Dealer.

 

[Kipwrite]

I looked closer and the serial number is as follows

677-S025181

I mistook the S for a 5.

 

[Mohawkmtrs]

OK, this is what I got:

First, Mercury started manufacturing 8HP Mariners in 1986 (so yours can't be a 1989 as it was made by Yamaha).

The prefix "677" was used during the years 1977 to 1985.

Given the above, according to Marinshopen:

1979 8hp, manual start, short shaft

Serial# Range: 677-018181 - 677-026995.

Absolutely no mention of an "S" in a serial number.

My only guess on the "S" is the motor was a factory re-built.

 

[Kipwrite]

Thanks. This is really helpful.

 

[Kipwrite]

So the S stands for short shaft and this motor is the mid-70s Yamaha motor. Bought it, and it seems to run well and appears unmolested.

The original owner replaced the plugs a few years back and has changed the lower leg oil, replaced the starter rope once way back when and kept things greased, but done nothing else. Hasn’t gotten much use and looks pretty new.

As the impelller is 40 years old that’s the first thing on my list. Will also pop in a new condenser.

Question: why can’t I find the impeller on the parts diagram? Assume it lives at the top of the lower leg? Anyone have a part number for this?

What else would you change out in terms of preventative maintenance on a lightly used 40 year old outboard that runs well?

Thanks.

 

[Mohawkmtrs]

Go to marineengine dot com, click Mariner and go to the 8B model for diagrams and parts.

Maintenance is the same as any other outboard ( WP Kit, LU oil, possibly carb cleaning, etc.).

 

[Kipwrite]

So, replaced both spark plugs. Changed the impeller and lower unit oil. The starter cord was shot so we replaced that, along with a new starter coil spring. Greased all the important bits. Cleaned the fuel filter - was spotless. I left the condensers and points alone as well as the carb. Looking for a decent fuel tank as the one this motor came with is very old, and the new ventless ones seem troublesome. Anyone have a nice 6-gallon tank they want to part with? Starts on the first pull and seems ready for spring.

 

[Mohawkmtrs]

I often see the tanks on Kijiji for $25 - $50 CDN.

I went to our recycling depot a couple of years ago and found a 6 gal OMC tank, took it home, cleaned it out and all it needed was a new hose assembly.