1960's era mercury motors.

[Scott53]

I have a mercury 2 stroke outboard that was made in the early 60's and I'm not sure of the hp.The color is white.When I bought it it had a 9.8 hp sticker on the cowl.I believe it's a long shaft.The serial number is 1581225 on the lower housing.The part that goes around the base of the motor which I call a pan.It's black in color and it has a 6 hp sticker on it.I've been trying to get info by using the serial number.That number tells me that it's a 1963 merc 60 6hp.I wanted to check the engine block for identification and found a part number on cylinder part of the block.Its 837-1903 with a 1903A description number for the whole engine block.I found a block on ebay that had that number on the engine block.The description said it was a mercury 110 11 hp.Were the engines interchangeable with different models?I also looked at the bolts that are for mounting the motor to the lower housing and they were rusted and don't look original.Do I have a pieced together outboard?The cylinder block part number 837-1903 and the 1903A numbers are the only info i have for the engine.Could someone help me out and identify what hp motor I have?

 

[Chinewalker]

Re: 1960's era mercury motors.

The model 110 was a 9.8hp, not 11. It was approximately 11 cubic inches and usually had the word LIGHTNING cast into the side of the water jacket on the intake port side. The 6hp had the word COMET cast into the block. This is NOT to be confused with the later 7.5hp block that had the word COMET stuck onto the block with a sticker, above the cast-in LIGHTNING designation. They are very different blocks! The cast-COMET block is 7.2 cubic inches, while the sticker-COMET block is an 11 cuber with smaller porting than the 9.8 block.

 

[oldman570]

Re: 1960's era mercury motors.

It sounds like you have what is referred to as a Franken Merc motor by some here on the forum. If memory serves me right, the boating industry switched the old 10HP rated motors to 9.9 so they could be used on some of the smaller lakes with a restriction of less than 10 hp. They also started rating the HP at the prop instead of the flywheel about the same time. Several parts of the smaller motors would interchange with other years of motors, and this is probably what has happened to your motor. JMO
Oldman570

 

[Scott53]

Re: 1960's era mercury motors.

The model 110 was a 9.8hp, not 11. It was approximately 11 cubic inches and usually had the word LIGHTNING cast into the side of the water jacket on the intake port side. The 6hp had the word COMET cast into the block. This is NOT to be confused with the later 7.5hp block that had the word COMET stuck onto the block with a sticker, above the cast-in LIGHTNING designation. They are very different blocks! The cast-COMET block is 7.2 cubic inches, while the sticker-COMET block is an 11 cuber with smaller porting than the 9.8 block.

Thanks for the info.My block has the LIGHTNING on it.I checked the year and it's a 1963.This clears things up.Thanks again.

Scott53

 

[Scott53]

Re: 1960's era mercury motors.

It sounds like you have what is referred to as a Franken Merc motor by some here on the forum. If memory serves me right, the boating industry switched the old 10HP rated motors to 9.9 so they could be used on some of the smaller lakes with a restriction of less than 10 hp. They also started rating the HP at the prop instead of the flywheel about the same time. Several parts of the smaller motors would interchange with other years of motors, and this is probably what has happened to your motor. JMO
Oldman570[/QUOTE

Thanks for the information.It was very helpful.

 

[Scott53]

Re: 1960's era mercury motors.

Thanks for the information.It was very helpful.

Scott53