Building a Super Mod 2 cylinder Mariner/Yamaha

**Fastjeff57** · 02-23-2012

Does anyone know what one of these twin Yamaha power heads weigh?

Jeff

**WalkWithMax** · 02-23-2012

Don, You may have to hook me up with one of these for next year! Or maybe I will still go with my '74 OMC 50 sizzler? My 50 has different pistons than the newer motors. The top ring is very close to the top of the piston. The motor is in great great shape, and I installed new rings, but I wonder if it will make decent power or not? Any thoughts on the older 44ci vs the newer 2cyl 50's and 60's?

**OUTBOARDER** · 02-25-2012

Originally Posted by WalkWithMax

Don, You may have to hook me up with one of these for next year! Or maybe I will still go with my '74 OMC 50 sizzler? My 50 has different pistons than the newer motors. The top ring is very close to the top of the piston. The motor is in great great shape, and I installed new rings, but I wonder if it will make decent power or not? Any thoughts on the older 44ci vs the newer 2cyl 50's and 60's?

the pic of the white boat $500, 200lbs old pro did beat 2003 APBA short course nat and AOF nat winner from behind 3 heats at Camden NC oct 2003. There are a couple d mods out there that are faster than we were back then but not with punch out of turn. That power head blew 225 psi on the comp gauge! John Runne said the throttle was like a light switch
on or off.

**Mark75H** · 02-25-2012

To me when it came on the pipe it felt like suddenly being kicked by an elephant ... and that was before it was "right"

**Hounddog** · 03-09-2012

http://www.ebay.co.uk/itm/YAMAHA-MAR...item58914982f9

DRIVE SHAFT HOUSING
FOR 55 / 60 H.P.
STD SHAFT ( SHORT)
LATE '70, 80 & 90
2 CYL ENGINES
ALSO FIT SOME MARINER 55 / 60 HP
NEW OLD STOCK

Yamaha part no : 687-45111-00

Mariner part no: 1587-7163M

**Hounddog** · 03-10-2012

Originally Posted by hounddog

http://www.ebay.co.uk/itm/yamaha-mar...item58914982f9

drive shaft housing
for 55 / 60 h.p.
Std shaft ( short)
late '70, 80 & 90
2 cyl engines
also fit some mariner 55 / 60 hp
new old stock

yamaha part no : 687-45111-00

mariner part no: 1587-7163m

That did not last long!

**Hounddog** · 04-12-2012

Is anyone got on to building one?
Here is a very nice stock one. Great platform for the mod!

http://www.ebay.co.uk/itm/YAMAHA-60h...item1c25e886e6

**chris3298** · 04-14-2012

seen a lot of these motors around and had no idea there capable of so much power

**Hounddog** · 11-15-2014

Time to refresh this old thread. We should be able to get more first hand information with the resent replies on the T850 thread. Since 2012 this is what we have found out. Again this thread is all about the yamaha 60 D 2 cylinder model.
[1] I got a number of blocks. There is two different blocks for sure and maybe 3.
[2] there are at least 2 different heads. They even have different bolt patterns and gaskets.
[3] the last model of the 55 yamaha has a different block compared to the mid 80's mariner.
[4] Mark at Tuff boats tested a 55 hp yamaha on his Tuff 16 and got poor performance.

Question is: We know that these motors and the Nissan 2 cylinder model raced as a class in Japan on 12 foot tunnels and ran high 80 mph.
We now know that in 1988 a T boat with a 60 D Yamaha was running mid 70s mph. Why can't we get the same performance? What was different about those motors?

**Mark75H** · 11-15-2014

Originally Posted by Hounddog

Question is: We know that these motors and the Nissan 2 cylinder model raced as a class in Japan on 12 foot tunnels and ran high 80 mph.
We now know that in 1988 a T boat with a 60 D Yamaha was running mid 70s mph. Why can't we get the same performance? What was different about those motors?

The boat and the prop