40 HP Powerhead on a 50 HP Evinrude---in--->

[jnaarnold]

I am looking at a 1987 40 HP powerhead and can get a decent deal on it. Will it fit my 1986 50 VRO? If so, is it just compression ratio that is different? Evrything looks the same. Thanks....
John

 

[jnaarnold]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

The guy selling it is saying it is just the carbs that are different.....so, ten extra horses with different carbs??
J

 

[iwannagofast]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

I think it might be piston size that is different... I know the only thing different between my 85hp and my 135hpp is the size of the piston.

 

[Dhadley]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

Same block, crank, pistons & rods. Use your 50 hp intake, reeds and carbs. If the 50 head has a different number you could use it but you'll not see any difference on a normal recreational boat.

If your 50 was propped out at 5500 or less you'll probably not see any difference if you installed the 40 powerhead complete. You might see a slightly better holeshot. If your 50 was propped out at 5800 - 6000 you may see a slight decrease if you use the 40 intake & carbs.

 

[jnaarnold]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

As long as it's not compression ratio that is making the difference(ie, piston size). If you've read my other posts, I'm dealing with a engine/powerhead predicament now. I can obtain this complete powerhead for $300.00. Which would be cheaper, and faster than putting in pistons and boring the cylinders.
John

 

[Dhadley]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

The piston size can't be an issue since they're the same piston. As are the crank, rods & block.

 

[jnaarnold]

Re: 40 HP Powerhead on a 50 HP Evinrude---in--->

Thats what I wanted to hear...thanks...
John