1977 Evinrude 85 hp w a 140 carb?

[outlaw69]

I’ve got a 77 Evinrude 85 hp and wanting more power from it. I’ve been told carbs from a 140 and exhaust would work great. Anyone have any experience with this or can help. Thanks in advance

 

[racerone]

I believe the 77 model 85 is a smaller bore / displacement powerhead.-----Intake ports are smaller I believe.------Not sure if adding bigger carbs will boost power..-----Installing the " bubble " exhaust manifold may require disassembly and machine work.

 

[Faztbullet]

Ahh someone told you wrong

 

[jimmbo]

The 77 85hp uses a 92.6 cu in Block, not the 99.6 in block the 140 uses. In 1979, OMC started using a 99.6 in block for the 85hp
In 1971 and 72, OMC did use a 92.6 in Block to get 100 hp, however whether an 85hp block can be hopped up I don't know if the parts needed would fit on the later 92.6 in blocks.

If you were to put the 140 carbs on your 85 hp, and could get the Linkages hooked up, you would experience an unhappy engine, and erratic operation as the Carbs are too big, and wouldn't be metering correctly at any given Rpm

 

[racerone]

Let's face it.----These 2 stroke outboards and how they work are still a mystery to many folks !!