1986 90 hp powerhead swap

[spirtS niggeB]

Recently got a good deal on a 1984 Checkmate. The 1986 90hp evinrude has a scored cylinder and I am looking at swapping it with another engine block. I was wondering if anyone knew which years would fit on here. I am looking at a 1985 100 hp evinrude and a 1984 90 hp evinrude.

Any info is greatly appreciated.

 

[Chrisravosa36]

I Belive the 90hp 84' would fit, not sure about the 100hp. Is this new powerhead coming with all electronics and carbs? The 100hp might fit, but am not very sure about the carbs on it compared to the 90hp.

 

[emdsapmgr]

All the crossflows in that time frame have the same mounting. Some of the early 80's blocks have higher compression heads. The big difference is in the throat size of the carbs-cast into the front flange of each carb. 1 3/16" 1 5/16" etc. In the 88 year, the power packs switched from the older dual packs to the new single pack. Around the 85/86 model year OMC began rating their engines at the prop instead of the crank. Those newer engines make about 10-15% more hp, but have the same hp decals on the cowling. The are all VRO engines, should have the same power trim units.

 

[tommarvin]

Or, just tear it apart, and take it to a machine shop to bore and hone, then put it back together,then the motor will outlive you.

Free factory service manuals at www boatinfo.no/lib/library.html

 

[spirtS niggeB]

Thanks, I think that I will just bore and hone. Still would be nice to pop at least 115 horses on there.