1972 65hp Evinrude poor performance

[nagel88]

I’m still working out the bugs on my recently acquired 1972 65 hp Evinrude. I’ve kitted the carbs, replaced fuel lines, adjusted timing to the best of my ability (I do have the factory manual). <br />I am having trouble getting a smooth consistent idle, and top end is rather sluggish for that much engine on a 15’ boat. (I can’t quite get it on plane at wide open throttle.)<br />I have noticed that while it starts fairly well, after a short time idling the engine starts stuttering as if one or more cylinders were gradually dropping off.<br />I’ve not yet been able to do a spark check. Is this the first place to look, and if that checks out, what comes next?

 

[Solittle]

Re: 1972 65hp Evinrude poor performance

Check both spark and compression and post the results back here. Also what plugs are you using and what do they look like?

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

I won't be able to get back to the boat for several days. When I've had a chance to check all those things I'll post the findings.

 

[papasage]

Re: 1972 65hp Evinrude poor performance

check coils they may be cracked and loosein power when gitting hot . will it run good after it sits about 5 minutes letting the coils or the coil that is breaking doe cool off . my 70 did that and it ruined the crank shalft from running it with that cylinder not firing . dont know how long it was run as it was like that when i got it . crank and run a 1/2 mile then break down and after 5 minutes would run till almost on plane and brek down again

 

[tr918]

Re: 1972 65hp Evinrude poor performance

Check the condition of the electronics under the flywheel. I had the same problem on a 1972 65hp evinrude. I replaced the powerpack and coils and still had the problem. It ended up being the timer base under the flywheel. Before replacing it blindly, check to see if it is operating properly or if it is in obvious physical bad shape. When I pulled the flywheel and started inspecting things it was visually obvious that mine needed replacing.

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

I have reposted this topic as it's been some time between the post and getting an opportunity to check the motor.<br />As for spark, it easily jumps a 7/16" gap while cranking. The compression (using a crappy tester), is #1 107, #2 127 and #3 130 PSI. Plugs are QL77JC4 and look good, neither wet or sooty, or dry and white.

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

I don't know if anyone will see this addition to an old post, but I'd like to bring things up to date.<br />After exhausting my skills on this motor, I took it in to a reputable shop for link and sync and a general once over. I was assured it was running fine when I picked it up and paid the bill.<br />However, once I put it in the water, it was just the same hard starting, stalling when shifting into gear, ragged idle and no top end power. I'll have to wait till after the holiday to confer with the mechanic.<br />In the meantime, I'm wondering if I keep sinking money into this motor or start looking for something new.

 

[DHPMARINE]

Re: 1972 65hp Evinrude poor performance

At some point in time you have to admit to yourself that the motor is 34 years old.Generally after doing carb rebuilds,it's time to move on.Just to give you an idea of 'engine' wear,grab the throttle shaft on one of the carbs and move it up and down.I'll bet it moves quite a bit.New carbs have NO play,and you're close to 1/16 or more,and sucking in air.Now think of how your pistons look.<br /><br />I'm not coming down on you,just explaining my point of view on older motors.I love them,but feel they have limitations.<br /><br />DHP

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

Thanks for the opinion. I haven't sunk an awful lot into this so far. I feel that I've reached a point where I have to draw the line, especially with so many unanswered questions.<br />Even if I were able to overcome all the simpler issues, I still have a weak cylinder. There's no solution for that that I know of other that a roll of $100 bills, money that could be invested into something with more promise.

 

[R.Johnson]

Re: 1972 65hp Evinrude poor performance

My next step would be to pull the head, and take a good look at that cylinder, and piston with the low compression. Even doing all the work yourself, you can sink a lot of money into those older engines.

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

I've got my eye on a 70hp Mercury listed locally. It seems like a fairly equivalent replacement for what I've got now. The price is reasonable, and if it checks out as good as advertised, I think I'll go that route and the Evinrude can go directly onto Ebay. It's time for someone else to take a turn at busting their knuckles on this motor.

 

[DHPMARINE]

Re: 1972 65hp Evinrude poor performance

Sounds like a plan.One bit of advice when changing engine brands.Make sure the newer motor has a control box.If not,it can cost $200 plus for a new one.Cables cost about $35 a piece.Just a mistake I've seen too many people make.<br /><br />DHP

 

[alden135]

Re: 1972 65hp Evinrude poor performance

This post is not made with any illusions that I know more than DHP or others. I was just wondering if you de carbed the motor to try to even out the compression. Seafoam's only 6 bucks. Just curious if it may be worth trying.

 

[nagel88]

Re: 1972 65hp Evinrude poor performance

Thanks all. The motor I'm looking at does have the control box, cables, wiring harness and a prop. So, it's pretty complete. <br />I know I could still try one thing or another, and hope for a payoff, but my hopes are evaporating quickly. I could probably pick up a can of sea foam today and give it a try, but I think that's just grasping at straws.

 

[R.Johnson]

Re: 1972 65hp Evinrude poor performance

A 20+ difference in compression could most likely mean stuck ring's, and that quickly leads to a scuffed piston. Nothing in a can will bring that back. I would still pull the head, and look. That does'nt cost anything. If you find damage, bolt the head back on. You won't need a new head gasket in that case.

 

[tashasdaddy]

Re: 1972 65hp Evinrude poor performance

put the 72 on ebay for aparts engine