1974 Evinrude compression issues ( kinda long sorry)

txbandit44

Petty Officer 2nd Class
Joined
May 11, 2008
Messages
182
ok got a 74 70hp w/o TT Evinrude came with a starcraft i bought trying to see if its worth titling or fixing.Heres quick run down of what I have done. To start off I want to say im no stranger to a motor or the 3cyl johnson/evinrude but I have never seen this.

Got the motor had no starter. It spun over by hand so i layed it on the floor withthe spark plugs up ad shot some wd40 in the cyl and worked it over by hand a few times. I used the pull start rope to do a half a** compression test to see if it was even worth getting a starter. #1 95 #2 120 #3 110.

Thought that was good enough to drop 50 bones on a starter got one and installed it got some tw3 and squired a few shots in the cyl and let it sit over night while laying plugs up.

got the motor up on a stand and spun it over with the starter to blow out any unneeded oil. recheck compression
#1 105 #2 150 #3 140

#1 worries me but I feel that if i get it running maybe it will even out after it warms up. I pulled the carbs and cleaned them up(NO I didnt pay 20 bucks for kits just a quick clean up)
Did rebuild the fuel pump I had an old kit onhand.

hooked up the water...fuel primed...bumped key and off we go. This thing runs great if i do all the throttle and timing adjustment by hand the PO didnt have a clue what they where doing and made all kinds of timing and throttle adjustments in efforts to get it running again. Which i can only assume they burned up the starter and thats why it had no starter. I would say I got some float issues cuz this thing leaks fuel from the carb throats like crazy while its running.


I got no dought i can fix anything on this motor exept compression issues. Its easier and cheaper to find another motor than have this machined.

Im looking at $60 for title and reg plus the leg work, got a title but cant find the BOS $100 in misc parts to freshin up the carbs and timing. Id say I got $100 in it now. Do i keep going or is that #1 cyl a deal breaker. I have never had a compession diffence like that and the motor start and run so well.


Thanks for the info in advance
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1974 Evinrude compression issues ( kinda long sorry)

35-45 psi difference is more than I'd take a chance on. I might pull the cylinder head, just to take a look-see. If the rest of it is in good shape, you've got a heck of a deal on a good lower unit. Find one with the lower unit buggered and combine the two... Your lower unit should work on any of the hydro-mechanical shift motors from 1973 (65hp) to about 1976 (or was it 1977 - I can't remember for sure)...
 

txbandit44

Petty Officer 2nd Class
Joined
May 11, 2008
Messages
182
Re: 1974 Evinrude compression issues ( kinda long sorry)

I think im going to pull the head and see if there any gouges that would tell me for sure. If the cyl walls are clean with no major ridge and the head gasket is in good shape. i wonder if i could re ring it?
 

txbandit44

Petty Officer 2nd Class
Joined
May 11, 2008
Messages
182
Re: 1974 Evinrude compression issues ( kinda long sorry)

LOL found the problem. #1 and #3 pistons have chunks missing. I borrowed a bore scope today and wow what a mess on #1. Ill take pics and post if i can figure out how.
 

txbandit44

Petty Officer 2nd Class
Joined
May 11, 2008
Messages
182
Re: 1974 Evinrude compression issues ( kinda long sorry)

wow those suck. I will try that again with a different camera
 
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