want more hp

[unhip_crayon]

Is there any way I can increase the HP in my 77 70hp evinrude? I wanna turbo charge it but im pretty sure it cant be done.

 

[reload]

Re: want more hp

The best way to increase hp is to increase the size of the motor.


You can mill the head to increase compression but that usually causes more problems then enough. Also anything you do to increase compression (power) puts more strain on the heads, rods, crank, rod and crank bearings, etc.

 

[jtexas]

Re: want more hp

there's a 75hp built on that same engine block.....I could be mistaken but I believe its just the cylinder head, reeds and carb jets that are different.

 

[HighTrim]

Re: want more hp

I think in the long run its cheaper and less problems to upgrade the motor..

 

[Chinewalker]

Re: want more hp

The bigger difference between the 70 and 75 is the porting. The blocks have different part numbers... Only way to turn a 70 into a 75 is to swap powerheads. The 70s tend to have better bottom end getting out of the hole, while the 75s tend to be better at the top end, really coming to life on a light hull...
- Scott

 

[tashasdaddy]

Re: want more hp

sell it and buy what you want. ahead in the long run.

 

[mikesea]

Re: want more hp

trying to tweek for speed could only be a waste of time,money and performance in other areas ,like idle.Motorheads play with boring and oversize pistons,porting,shaving heads,adding boyseen reeds ,engine height,props.Then there are things you can do to the hull if its some kind of go fast boat.But as stated,your best to go bigger hp,