1964 evinrude 40hp

[cluke3]

compression 60lb both cyls is this accecptable

 

[CATransplant]

Re: 1964 evinrude 40hp

That's low. When I started working on mine, compression was only 85, and it ran. Can you describe how you did the compression test? If you did it incorrectly, that could account for the low compression reading.<br /><br />If you did it correctly, there's still hope. It's entirely possible, if both cylinders are the same compression, that the head gasket is leaking. That's easily fixed. If the engine has been sitting for more than a year or two, the rings may be stuck. That's generally easily fixed, as well.<br /><br />I'm assuming this is an electric start engine. If so, pull both plugs, screw in the compression gauge and crank the engine through several revolutions or until the gauge doesn't rise any higher.<br /><br />If it's still low, try laying the outboard on it's front, with the spark plug holes vertical and put about a shot glass full of Sea Foam or other decarboning fluid in each cylinder, and let it sit overnight. The next day, crank the engine to blow the Sea Foam out and repeat the compression test.<br /><br />If still low, then it's time to pull the head and have a look.<br /><br />These are very nice engines, very durable. Most parts are readily available, although engine internals can be troublesome to find. <br /><br />Lots of folks here who own Big Twins, so you'll get lots of help here.<br /><br />Let us know what you find.

 

[cluke3]

Re: 1964 evinrude 40hp

just replaced head gasket runs fine above idle<br />at idle it dies

 

[cluke3]

Re: 1964 evinrude 40hp

lower cyl had a small scrach in it running lenth of cyl wall

 

[CATransplant]

Re: 1964 evinrude 40hp

OK, if it runs fine, then it's likely that your compression reading is incorrect. When you say it runs fine above idle, are you talking about running in the water on the boat or just in a tank? There's a big difference.<br /><br />Failure to idle can be caused by many things, but we'll have to run them down one at a time.<br /><br />First off, how did you do the compression test? Let's get compression out of the way before we move on to your idling problem.<br /><br />It's really a game of 20 questions here. The answers to the questions suggest the next question. Here are some of them, and if you answer them, we'll work out the idling problem.<br /><br />1. Was this outboard running well for you at any time?<br />2. Why did you replace the head gasket?<br />3. Again, how did you test compression?<br />4. Has this outboard been sitting for a long time?<br />5. What other work have you done to it?<br />6. As I asked above, have you tested it on the boat in the water?

 

[cluke3]

Re: 1964 evinrude 40hp

tested in the water<br />checked compression as you said been sitting for 2 years rebuilt card replaced thermostat synk n link useing autolite plugs replaced coils wires points condensors not sure if this has the right carb

 

[CATransplant]

Re: 1964 evinrude 40hp

I checked your earlier thread on this outboard, where Paul Moir was helping you. At the end, about the middle of this month, it seemed to be running OK. Was it since then that you did the head gasket? <br /><br />The scratch in the lower cylinder: How deep was it and were there scuff marks around the scratch. If you ran your fingernail across the scratch, did it catch on the scratch?

 

[cluke3]

Re: 1964 evinrude 40hp

never idled good did head gasket after paul helped me never did a decarb

 

[CATransplant]

Re: 1964 evinrude 40hp

OK,<br /><br />Once you answer all the questions, I'll do my best to help you, but I can't do much without answers. Don't be afraid to type a long message.

 

[cluke3]

Re: 1964 evinrude 40hp

replaced fuel pump to

 

[cluke3]

Re: 1964 evinrude 40hp

no scuffing around the scratch barely could hang my nail in the scratch

 

[CATransplant]

Re: 1964 evinrude 40hp

Scroll back up the thread. I asked you a few questions. Without the answers, I don't have a clue as to your idling problem.

 

[cluke3]

Re: 1964 evinrude 40hp

i answered your questions

 

[cluke3]

Re: 1964 evinrude 40hp

#1never ran good since i had it<br />#2just to check it was overheating<br /> #3 did compression check as you said<br />#4 this outboard been sitting 2 years<br />#5 rebuilt carb-replaced coils points condensors and plug wires replaced fuel pump and thermostat<br />did link n sync<br />#6 boat was tested in the water

 

[CATransplant]

Re: 1964 evinrude 40hp

OK, it's time to clean that carburetor again and install a carb kit, then adjust the low speed setting correctly. You've done all the other stuff. You may still encounter a problem due to the low compression. If you haven't checked it in a while, try checking it again, using a different compression gauge. It may have gone up since you've run it for a while.<br /><br />Search here on iboats for "decarbonizing". That's a possibility.<br /><br />If all that fails, and the compression is really just 60psi in both cylinders, it's likely that it will never idle well. That's really marginal for this engine. It might run at higher RPMs with that compression, but fail to idle.

 

[cluke3]

Re: 1964 evinrude 40hp

thanks if i do a decarb do you think this might help also i never pulled the sealded plugs on the carb whew i had it off to rebuild it if all else fails do you know where i can find pistons and rings

 

[CATransplant]

Re: 1964 evinrude 40hp

A decarb might help. It helped my 35. Before the decarb I had 85 psi compression in both cylinders. After the decarb, plus a couple hours of wide-open running with SeaFoam in the fuel, it went up to 105.<br /><br />Again, since you've had it running a bit, recheck the compression, using the same gauge. If it reads the same as before, try another gauge. They're notoriously inaccurate. <br /><br />You can get the pistons and rings for this engine, but that's the last resort. I'd like to see some more tests. A single vertical score in a cylinder can be lived with in two-stroke engines. Really low compression, on the other hand, will keep it from running properly.<br /><br />Also, if you didn't pull the plugs on that carb and blow out the orifices with compressed air, you really should do that before you go a lot further. Lots of little passages and orifices you can't get to any other way. If you do that, you might just have an engine that idles OK without going any further into it.

 

[BoatBuoy]

Re: 1964 evinrude 40hp

CAT,<br /> You might have missed it, but up in this thread cluke says he's using Autolite plugs. Shouldn't he replace these with the correct Champions?

 

[CATransplant]

Re: 1964 evinrude 40hp

Hah! I did miss that. Champion J4C plugs for that motor, or J6C plugs if it's going to be trolling. <br /><br />That probably isn't the essential problem, but who knows how old those plugs might be. Always better to have the right plugs.

 

[cluke3]

Re: 1964 evinrude 40hp

i will redo carb and try the seafoam and recheck<br />compression will let you know what happens<br />thanks for the help