1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

[SHUMAKEB]

I have a 1972 Evinrude 65 hp. I had it out on the lake this past weekend and it was running bad like it had water in the gas. So I stop in the marina and buy their 2.09/gallon gas and their oil. I took off from there noticed little improvment in performance so I take the boat back to the boat ramp and pull it outof hte water and pull out the plugs the bottom cyl. had a foulded plug (oil on the electrode no water) so i cleaned it the best i could and put it back in and put my boat back in the water. I noticed a significant improvement. It still took about 5 mins to get up to speed and start planing out. It was running good for about a min wide open then i noticed a major reduction in power like i lost a cyl. I pulled the boat out of the water jerked it on home. Today i checked compression in all the cyl's. and the top cyl had<br />125, the middle cyl. had 125, the bottom had 35. So im trying to figure out what is the next step that is a major difference in compression. Is there anything i can do please let me know what you think and kind of cost estimate. <br />Thanks,<br />Bryan

 

[hondon]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

Next step is pull the cylinder head and tell us what you see in there.Could be just a bad head gasket.

 

[SHUMAKEB]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

I pulled the head off where the spark plug screws in at and the one that was fouling the plug looks like a penny that you would find on the interstate after it had been ran over a 1000 times. Numerous small chunks are missing out of the head...the cyl. has no damage done to it but the piston and the head has some problems. Is there anything i can re-dome this piston or not without pulling this thing apart. If I need to or do you think it would be feesable to rebuild this motor. How much you think it would cost to rebuild this motor with me doing it or taking it to a shop. Thanks,<br />Bryan

 

[Droll]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

the cyl. has no damage

Looks like you won the lottery , all those smal chunks were made by an foren object , my guess > the rings .<br /><br />

Is there anything I can re-dome this piston or not apart

Get a new piston + rings ( If it´s not to bad , you might be able to fix some of the damage but .....)<br /><br />

without pulling this thing

Sorry to say this but , no .<br /><br />

How much you think it would cost to rebuild this motor with me doing it

You will need the following parts :<br />Manual<br />New piston + rings ( 3 sets )<br />Some gaskets .<br />3 carb kits .<br />I would also change crank/rod bearings .<br /><br />But the first thing to do , find out why this happened , or it might be happening one more time .

 

[R.Johnson]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

When dealing with an engine of that age, rebuilding can be a hard call. Taking it to a shop is going to cost more than the engine is worth. If you have the tool's, and a good manual, that three cylinder is really not that hard to rebuild. The damage you are looking at is a piston breaking up, and the only way to deal with that is a tear-down. You really can't tell what the cost will be until the engine is apart. Where we're getting this late in the boating season, you could make this a winter project. That way you could take your time, and do some checking around on parts. What ever way you go, you will want to find what caused the failure. Probably a carb leaning out.

 

[SHUMAKEB]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

I checked out a clymers and seloc manual today from the library. I was thinking to myself that piston and head damaged was caused by a foreign object it tore up the head and the pistion. It looks like the piston kept throwing the object agaisnt the head but hard to say. The very first time i had this motor in the water i couldnt get it to plane out or anyhting like that. I ran it for about 4 hours or so like that. I noticed a lot of oil looking stuff in the water around me and the boat was using a lot of gas so I traced down the fuel lines and the one going to the bottom carb had dry rotted and was leaking. So i replaced all the fuel lines that i could have gotten to at that time. I dont know if thats what did it or not but i have taken the boat out 6 or 7 times since then and it ran good to mediocre most of the time. It seems like every time i went out i would have a problem like my floor rotted out last season i pulled all of the floor and the stringers were all infested with thousands of ants and when i say thousands i mean thousands. replaced the floor but took it out again and forgot to put the plug in so now i was hauling around an extra 50 gal of water but i had fun all of the times. Boating is an expensive hobbie. Thanks, I will keep posted on everything that is going on. I have got digital pictures of this head i would like for some one to see it so they could tell me what they think has happend.<br />Thanks,<br /> Bryan

 

[Solittle]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

Bryan - I'm sure that pictures may shed some more light on what went on but you won't get a complete diagnosis until you disassemble it. Your pictures will not show the pistons (other than the top) or the rings.<br /><br />Ain't these old boats fun?<br /><br />Your motor should be repairable and could give you many more years of good service. Best case with minimal internal damage I would guess you could get it running for a couple of hundred. If you decide to do a complete rebuild you can double or triple that. It could be a fun project. Is it worth the time and effort - - ? - - your call on that one.

 

[SHUMAKEB]

Re: 1972 65HP EVINRUDE FIX OR REPLACE 90 PSI DIFF PER CYL.

You have to tear this thing all the way down right. So I think and feel that I should probably replace and rebuild things that need rebuilt because i have it all apart now i would rather do it once than three times. I think I am going to have the carbs re-built- they dont need it. Im going to put new gaskets and bearings in it and a new water pump and some new fuel hoses anything that looks like its rubber and has some dry rot to it im going to go head and replace it. Is their any other suggestions that i should replace while i have this thing torn down. Let mne know Also when i pull this flywheel is there something i can do so i will not throw the timing off or will just get thrown off and have to reset it? Anything else that i might want to know in order to save time and money on this project?Thanks,<br />Bryan