1975 Evinrude 70hp. Is it worth fixing?

A

AC156

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May 18, 2008
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I've got a '75 Evinrude 70hp on an old Glastron bass boat that I have had for a little over a year now. The last time I took the boat out it would not run right. After doing a compression test I discovered that the middle cylinder was low on compression. I took the engine apart and it looks like something got into the cylinder and beat the piston up pretty bad. I am going to need a new piston and rod. There is a small scratch in the cylinder wall but I don't want to sink a lot of money into this engine so I really don't want to have it bored out. I have looked for parts on this site, as well as others, and it is difficult finding parts for this engine. I have found parts for later models but not one this old. Will a rod and piston on a later model engine work in one this old? Is this engine even worth fixing? I am considering trying to find a later model engine to put on the boat.
 
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Daviet

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Re: 1975 Evinrude 70hp. Is it worth fixing?

I would guess it depends on how much a different engine would cost apposed to how much it would cost to rebuild the one I have. There are a ton of those engines around and i would think parts should be available. You did not list a model number , I would check a couple of parts sites for parts.
 
bktheking

bktheking

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Re: 1975 Evinrude 70hp. Is it worth fixing?

IMO any engine is worth fixing if it is feasible. Try honing out the scratched cylinder and see if the scratch goes away and measure the bore, that's the first thing i'd do before ordering parts. Some engines aren't, motor that are sunk and that have rusted inside are garbage. I just finishing rebuilding a 9.9 powerhead a dealer classified as junk. Honed, re rung and reassembled, tonnes of compression now. But remember, it was junk and I got it for nothing. I spent $140 in parts, try and buy a new 9.9 for that.
 
A

AC156

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Joined
May 18, 2008
Messages
14
Re: 1975 Evinrude 70hp. Is it worth fixing?

The serial number of the engine is 70573E. I have found pistons for this engine but from what I see I will need to get a wrist pin bearing conversion kit. I guess they changed the size of the wrist pin on later models. Is this correct? Will I be able to use the old rod with the new piston if I get the wrist pin bearing conversion kit?
 
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