MARINER 30HP PERFORMANCE UPGRADE

Hi i read some time ago on thi

Hi i read some time ago on this forum that you can upgrade a mariner 30hp to 40hp by changing the carb and read valve.
My question is will this work on my mid 90's mariner oil injection model? im told my mariner is actually built by yamaha?

"Here's what (little&#

"Here's what (little) I know:

The Yamaha designed Merc engine series consists of a family of engines designed about a 20 cubic inch cylinder. To wit:

Two cylinder motors (40 cube) are 30 and 40 hp. The 40 hp engine (20 hp per cylinder) is de-tuned with (probably a smaller carb, tighter tuner, and possibly milder porting) to make a 30 hp motor (15 hp per cylinder). It's easier that way.

Three cylinder motors (60 cubes) run from 40 to 60 hp. The 40 hp version (note that it's also 15 hp per cylinder) is the de-tuned version of the 60 hp (again, 20 hp per cylinder).

The 90 hp is a larger engine (85 cubes) is already at its max, with de-tuned versions of 75 hp, so you're out of luck.

Jeff"

"Thanks for your response but

"Thanks for your response but Im still confused by the whole thing, is an oil injection model carb any different to a none oil injection model?"

"Probably similar. On another

"Probably similar. On another site, there was a MASSIVE discussion on whether changing oil to gas ratios changes the jetting. The opinion was that it is not significant--and they were talking 50:1 down to 18:1.

Jeff"

"Thanks, i noticed mine mixes

"Thanks, i noticed mine mixes the fuel before it gets to the carb.
i read somewhere that the 30 and 40hp use the same carb the only difference is the reed valves???????????????"