Bringing life back to a 1959 evinrude 5.5hp outboard

[bobrown]

I have a old evinrude 5.5 that was given to me, a couple years ago i put a new impeller and a carb kit in it and the lil thing fired right up after a bit of tinkering.. now it has set with ethenol and gas in the carb for two years, so im going to do a small rebuild on this.. I planned on porting but i see i can only get to the exhaust side ports, the pistons will have to be out to even see the intake side ports.. im getting pics now...

 

[Blaaster]

Is there a spacer plate between the carb and block?

 

[bobrown]

 

[bobrown]

yes there is a plate between, it the carb bolts to it, let me go take a pic of it too.. the hole looks a lil small

 

[bobrown]

 

[bobrown]

Ok im trying to get the pics of the spacer up now...

 

[bobrown]

 

[bobrown]

 

[bobrown]

What part is the one that makes the difference in power.

 

[Blaaster]

Looks like a challenge as it looks like a model before they used the restrictor.

You can find out if the intake is large enough by measuring the area of the intake port or ports to the crancase. The combined area should be slightly smaller than the carby intake.

Looks like you can have some fun porting and polishing the exhaust side she's a little uneven in there.

 

[bobrown]

I thought they were all the same up until 1964

 

[Blaaster]

I have a spacer hanging in the workshop which I just went out and looked at, and my old memory (which is pretty old) kicked in and I remembered it to be off a 1980 model.

Maybee I have you up the wrong tree and am barking needlessly.

 

[bobrown]

Yea, well i still find it odd, if you look on ebay or anywhere at the 1954-64 evinrude 5.5 and 7.5s they sell the parts like pistons and cylinders and say they fit both, and that does not make sense..

 

[bobrown]

So do you think that i could port the intake plate a lil, and do you think i would gain anything by cleaning up and maybe opening up the exhaust a lil bit?

 

[Blaaster]

Open up the ports a bit and clean up and polish the surfaces.

Outboards use advancing the ignition as a means of producing power as well, maybee you could advance it up a little but listen out for detonation.

 

[Larry's Shee]

I would be careful of raising ex or lowering intake as it will change the powerband. Intake port timing on a piston-port affects powerband much the same as the exhaust (see Gorden Jennings)

 

[bobrown]

im am hoping to just edge out a lil more power, i kno the lil thing is very old and for sure has flaws that can cause it to run poorly, i want it to be reliable but also want it to push my 14 foot boat a lil better, i can see that all the exhaust and intake ports look like the factory used a big drill bit, and didnt clean it up the ports definitly need attention..