1965 evinrude big twin 40 e/s wont start and stay running when hot

[dannynurse]

i have a 1965 evinrude big twin 40 with electric start.it has been acting strange for the past month and is only getting worse. when i first took it out this year it would run for around ten minutes then quit and woulnt start back up until around 20 mins later. will turn over and everything but it seems like it is just flooding, gas comes out of a hole at the top of the carb while its turning over, i replaced the coils, points, and condensors. new gas, new plugs. it ran fine for two weeks and now it will start and only run for a few seconds. then die again for 20 mins. pretty frustrating. it also wasnt spraying much water out, so i put a new impeller in it adn it still doesnt, is this normal? sorry for the long thread, any advice will be extremely appreciated. thanks for reading

 

[jbjennings]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

It sounds like your float needle may be sticking open due to a little piece of trash on the tip of the float needle. I would rebuild all carbs, and try it again. If the problem persists, then check spark with a spark tester (not by grounding the plugs on the head). I think you just have a sticking float needle which is flooding the motor. The spark plug gets wet and it won't start until it dries out. Then the fuel pump builds up too much fuel in the carb and the process starts all over again. If the problem persists after a carb rebuild and new needle/float/seat, then check the fuel pump diaphragm for a pin hole.
Your float could also be getting a little heavy if it's cork and has absorbed fuel/oil. That would also cause flooding.
Good luck,
JBJ
BTW, a check of the head after it's ran a minute or so with a cheapo infrared thermometer would tell you if it's overheating. I don't believe it should get over 160 degrees, probably staying between 140 and 150 degrees if it's pumping and circulating good.

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

thank you so much for the advice jbj. i will def try it but unfortunately will be a couple days or more til i can get the rebuild kit. but i will definately try it. the carb is the one thing i didnt really wanna get into cause ive never messed with one. i do have the manual though so hopefuly that will make it do-able for me. are there any other electrical components i should check just in case? or does it really sound just like a carb problem? thanks again!

 

[BoatBuoy]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

The carb on that moter is pretty simple. It's not much more complicated than the carb on you lawnmower. They don't have accelerator pumps like auto carbs. The biggest problem you'll have is just getting it off. The carb itself is a piece of cake.

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

ok great, i am going to go take it off soon, there is a carb kit i found on iboats (sierra marine) for less than $20 but it says w/o float. should i just go ahead and replace the float also? im already gonna be in there and its only 10 bucks so it seems to me like i should. also , one more question, this may be a stupid one too but i gotta ask just to eliminate any possible causes, would a bad battery have anything to do with the way its acting up? i really dont think so but you sound like you know a lot and your input would help. thanks again.

 

[jbjennings]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

A bad battery will ruin your starter, but the coils and magnets under your flywheel produce all the voltage for the spark plugs and therefore a bad battery won't make it run bad or quit. Does your motor have a generator/starter combo? Either way, I think it's just a carb problem. I WOULD get a new float if when you take yours apart you find it's a flaky old cork one. Those '65 40's are very reliable motors when they have good cooling systems, clean carbs, fresh fuel and fuel lines, and newer coils and such in the ignition. All of these things can be had relatively cheaply compared to parts for newer engines.
As the Boatbouy said, don't be afraid to rebuild the carb. You could do it without a manual they're so simple. Just soak the carb good and make sure ALL the passages are blown out with compressed air/spray carb cleaner, and put it back together. There is a thread in the "top secret files" at the top of this forum that has some instructions from Master tech Joe Reeves that are really good for getting your carb set back correctly--again, not hard at all or tough to figure out.
Be careful not to screw in the low speed jet on the carb too hard, or you'll groove the ned of the brass needle and ruin it. Be gentle.
Good luck,
JBJ

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

ok, now i have the carb off and it wasnt hard at all to remove, of course a ton of gas came out as well as some thicker black liquid. is the thicker black stuff something to be concerned about. im headed to get new fuel lines and clamps now. i cant order the rebuild kit til after the holiday. another thing i should mention is that these motors call for a 50:1 mix but the old man i bought it off from told me hes been mixing it at 25:1 because its always run better. i was a little skeptical at first but i decided i shoudl listen to him since thats the way hes been running it. should i have just stayed with the 50:1? and no i dont have the generator. all the mounts are there but no generator. and one more thing, what do you mean by "soak the carb good"? thanks again. you guys are great help

 

[kfa4303]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

Hi danny. That thick, black liquid should definietly not be there. Clean it all out. You'll also want/need to remove the welch plugs on the carb to get access to all the passages. Check the condition of you carb float as well. If it's one of the old, cork style, you'll want to replace it with a modern plastic float. The old floats break down over time, especially with modern gas, and relsease bits of cork into the carb which then clogs the passages. Once you've got the carb kit and the carb itself squeaky clean, you can reassemble it. Take care to get all of the packings installed in the correct order too. I agree with the old timer that suggested 24:1 mix along with Champion J6C plugs are your best bet. Better safe than sorry. The extra oil won't hurt your motor and will add an extra layer of protection. The link below should help with the carb rebuild. Assuming you have compression, spark in both cylinders and good gas she should fire right up. Be sure you're only run her in a test tank with water filled up to about and inch or so below the main exshaust port as these old motors can't run on muffs. Good luck. Keep us posted.


http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

 

[jbjennings]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

KFA,
I like to run plenty of oil as well, and put 16:1 in my 7.5's, 25:1 in my '50s bigtwins, but the '65 40hp has needle bearings on the crank mains, rods, and wrist pins, and I'm thinking OMC recommended 50:1. Why waste the extra oil?
Just curious and always eager to learn,
JBJ

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

ok great, i have most of the carb apart and it is an old cork float, so ill replace it with a new plastic one. there was that black liquid when i drained it but the bowl looks spotless on the inside. but its probably the passages that i should be more concerned about? and i should just spray the carb cleaner right through the passages from both directions and let it air dry, right? also what should be included in the rubuild kit? looks like a lot of gaskets and the needle and seat that are attached to the float.

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

another thing that i think is worth mentioning is that when i took the heat exchanger off theres the threaded hole at the top where the fitting for the pipe connects to the outboard but theres also another threaded hole at the bottom just open with nothing in it? is this right?doesnt seem right to me.

 

[jbjennings]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

Packing washers for the low speed needle, a donut gasket for the main nozzle (I believe), main carb body gasket, float bowl plug washer. There may be extra parts that go to other model carbs as well, so you may have extra parts.

I like soaking the carb in chemical carb cleaner overnight or a couple of days if I can. But a lot of the time you can get away with just blowing out the passages with carb cleaner. Use a fine copper wire to clean the high speed orifice. I would not remove the high speed orifice plug, because it requires a special screwdriver to remove it without breaking it. You need to get the high speed orifice totally clean for it to work properly. You might be especially careful you don't scratch the walls of the orifice because it has to be extremely precise in diameter to function properly. Sometimes if you can't soak it in chemical cleaner a wire is necesary to remove any scale that might restrict the orifice (hole) that the fuel passes through. If it's too small, the motor will run lean and potentially burn a piston. Just get it clean and don't worry about it. I'm unsure what you mean by heat exchanger, but there are some parts diagrams available at marineengine.com that will help you identify parts and their location.
http://www.marineengine.com/parts/v...ntage-evinrude-johnson/380577/38057700001.htm
Later,
JBJ

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

well guys i have everything back together but unfortunately its pouring and thunder and lightning up here in maine so i wont be able to tank test it till tomorrow. one thing i noticed was that the last person to freshen up the carb didnt put all the packing and washers in the slow speed need. there was supposed to be four parts all together and they only used two. and it looks like the end of they needle is slightly distorted from being tightened too far and hitting the back of thge chamber. looks like ill probably have to replace that too. my local boat shot had the carb and fuel filter/pump rebuild kit( i went ahead and did the filter and pump also) so hopefuly they will have the needle aldo. ill let you guys know. thanks again for all the help! if this doesnt work i dont know what to do...

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

no luck its still not right. starts cold like a dream, runs great for 5- 10 seconds then gas pours out of the carb.... my buddy seems to think its the float as well or possibly the automatic choke. guess im gonna have to mess with it again tomorrow. anymore advice would be greatly appreciated, thanks for all the help

 

[jbjennings]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

If it were me, I'd take the carb off and take it apart. Get the half of the carb with the float and bowl and fuel line nipple and hook it back to the fuel line. Pump the primer with the bowl upside down so that gravity is holding the float in the closed position and see if the float needle is totally shutting off the fuel. My guess is that there is still a piece of grit in there under the float needle, or your float is improperly adjusted or soaked with fuel. SOMTHING is letting the fuel bowl overfill and that's what is causing it to overflow.
Good luck,
JBJ

 

[samo_ott]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

Or turn the carb over and blow into the fuel inlet nipple and it should be sealed with no air going though it. Then turn it back normal and blow again and air should go through.

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

well got it all straightened out, the float was fetching up on the side of the bowl. i had to bend the arm a little but took it out on the lake tonight and its never run better. im pretty happy....EXCEPT the electric start stopped working,lol. theres a clicking noise in the junction box. how can i test the solenoid? i also know that i should try tapping the starter. im going to get to it tomorrow. thank you all for all the great advice. it pull starts on the first pull so im not too worried about it now, but im def gonna look into it.

 

[samo_ott]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

Usually if the solenoid is clicking, the battery is low.

 

[dannynurse]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

yeah thats what i thought but the fish finder, lights, phone charger, etc all worked, just not the starter. but ill hook it up to the trolling battery and see how that goes.

 

[samo_ott]

Re: 1965 evinrude big twin 40 e/s wont start and stay running when hot

That's all low current demand stuff... I still say battery.. I wouldn't do anything else until that was verified.