61 Evinrude 40HP- no power/ burns tons of gas

[matth121]

Hey guys- just got my newly acquired 61 Big Twin 40 HP(has less than 20hours apparently) onto my boat and into the water. Was expecting big things from it but was disappointed. maybe 7 mph at full throttle- less than my 18HP merc would do on this boat and that thing had problems. I figured, ok, its been laid up for years, might just need to run it a bit. up the lake and then back down to where i launched, im gonna guess a round trip of 4 miles, made it back to shore and then noticed my 6 Gallon tank that was 1/2 full was now just about bone dry- wtf?!?!

I'm sure ive got lots more to check but heres what i do know. Its not running hot- suprisingly cool actually. Starts and runs great in a bucket and on the lake. it doesnt seem to want to rev very high in neutral or in gear- id be guessing but i'd say 2000 maybe 2500rpm at full throttle in or out of gear. Where should i start? I'm gonna pull the plugs and have a look at them but I'll be suprised if its only running on one cylinder. What could cause it to burn that much fuel with little to no power? I know its bigger than my 18hp but that thing would have gotten 4 or 5 hrs with that much fuel- not the 40 mins i was out with this. Appreciate any advice you guys might have for me, thanks

 

[lindy46]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Check compression, check spark. I'd bet it's only running on one cylinder.

 

[Bigkat650]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

1. Check your coils. They should not appear cracked or 'weathered'. The coils on the old Evinrudes are prone to failure, and are located under the fly wheel. It's the 1 part on these old 'rudes that was a manufacture oversight. IF that is the problem, replace them and the new coils are made better and you should not have any problems.

3. Check your plugs & wires. Plugs should be properly gaped without a lot of deposits on them. You should just go ahead and replace the plugs, as its pretty cheap and easy to do so. Your wires and fuel hoses should be free from cracks and voids. If you notice any issues, replace these as well.

2. Check your carb. The carb should be clean and obstruction free. You should replace the seals while your in there. Your high speed low should be set at 3/4 turn, and your high speed at 1.5 turns (double check that, I may have those backwards).

**I had these backwards, the low speed is 1.5 turns and the high speed is 3/4 turn


Report back the findings. If you need a manual for this motor, message me and I may be able to help you out. Good thing is parts are cheap for that motor and pretty readily available. Although not related to your current problem, it would be a good idea to replace the impeller at this point as well.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Will do, i'll post my #'s and findings for you later. Thanks for the reply

Check compression, check spark. I'd bet it's only running on one cylinder.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

i have a big qustion here- low speed pin is right next to my manual choke lever right? and my high speed is just about 2 inches to the right of the low speed pin right? thats what it says on them anyway- thing is the highspeed seems to be free spinning, i can flick it with my finger- it'll do 3 or 4 turns on the pin with no change to anything. The low speed has tension and is definitely adjusting the carb but the highspeed does nothing- guess you'll need a few pics to understand what i mean- I'll get them for you. Thanks for the input

2. Check your carb. The carb should be clean and obstruction free. You should replace the seals while your in there. Your low speed pin should be set at 3/4 turn, and your high speed at 1.5 turns (double check that, I may have those backwards)..

 

[Chris1956]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

I had the same issue. Turned out to be no compression in one cylinder.....

 

[Bigkat650]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

i have a big qustion here- low speed pin is right next to my manual choke lever right? and my high speed is just about 2 inches to the right of the low speed pin right? thats what it says on them anyway- thing is the highspeed seems to be free spinning, i can flick it with my finger- it'll do 3 or 4 turns on the pin with no change to anything. The low speed has tension and is definitely adjusting the carb but the highspeed does nothing- guess you'll need a few pics to understand what i mean- I'll get them for you. Thanks for the input

EDIT** I had the needles backwards, the high speed is a 3/4 turn

They have pretty long threads, so my assumption is it just needs to be reset. To do this, you turn and screw it all the way down to where it stops--the threads are very tight to allow for just ever so slight adjustments. Do not force it tighter when it stops. That is 100% closed. You then turn it open 3/4 turn, and that is the 'middle' start ground, I believe it would be the "3" on your dial. Fine adjustments may need to be made on the water.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

ok, compression 105 on upper, 102-103 on lower- i may not have had it at WOT when testing as i know my throttle cable needs a slight adjustment- That should be ok though right? Good spark on both cylinders although plugs were quite dirty, i cleaned em up and will replace shortly but they do spark. I've got pics of my carb, dont have time to upload them right now but will do tonight- my high speed jet is definitely either missing or not there or maybe this isnt the original carb, although that would really suprise me, hopefully the pics will clear it up. Should have em up later tonight after work

 

[Chinewalker]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Check to make sure it's running on both cylinders. Pull one wire, ground it to the block. Start motor and note whether it sounds the same as before. If it doesn't start at all then you've pulled the one it was running on. If it runs on both cylinders, then worry about the carb...

 

[kfa4303]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

+1. Sounds like you're dropping a cylinder. Here are some handy links.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/378462/37846200001.htm

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm

 

[BonairII]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

+1. Sounds like you're dropping a cylinder.

I agree.

Change the plugs immediately(don't leave the "cleaned" plugs in).

As other have mentioned, run the motor and pull a plug wire...if the motor stumbles/stalls, that cylinder is firing. No change= cyl not firing.

Check the quality of your spark with an adjustable spark tester. Verify that spark will jump a 7/16ths air gap.

Verify that you are running OEM recommended plugs (not what Joe Schmo at the auto store recommends).

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Ok, so next time i get it in the water/bucket i can check that. Can anyone tell me what the OEM reccomended plugs are? Guess i need a manual for this beast. Thanks for the help guys

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

pics of carb

like i mentioned- the thing marked high speed just spins freely- is it supposed to be connected to the...:facepalm:...i think i just answered my own question but.. is the dial up top marked highspeed supposed to be connected to the dial/screw located under the throat of the carb in the middle(anyone understand that)? it is isnt it, think i might be missing something if so. let me know what you guys think

 

[lindy46]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Yes, you're missing a rod which connects the high speed knob to the actual high speed needle, below. No problem though - just adjust the needle directly. First turn it clockwise and gently seat the needle. Then open it up about 3/4 to 1 turn. That's a good starting point.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

ok, so thats great info- thanks. now please, speculate for me... what would be the effect on the motor of having the high speed turned way out?? like maybe 2 or 3 turns out? I played with it a bit out on the water just to see if it would make a difference- think i was going out the whole time, it didnt change a thing and i wasnt sure what it was so didnt want to mess with it much, id say at most i put 3/4 turn out on it but may have alreay been out a bit to far. would that cause my problem? probably im guessing, would probably foul my plugs too wouldnt it?

 

[lindy46]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

There should be a "sweet spot" for best performance. If you are at the sweet spot and you turn the needle slightly in either direction, you will lose rpm's

 

[oldybutagoody]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

The affect of having the high speed needle 2-3 turns out would explain your poor performance AND your high fuel consumption. Turn it in till it bottoms (BUT NOT TOO TIGHT) then loosen 3/4 turn. That's your rough staring point. Then, in the water, on the boat, under load, in forward at high speed, slowly turn the high speed needle in till it loses RPMs then back it out 1/8th to 1/4 turn. Then forget it.

ok, so thats great info- thanks. now please, speculate for me... what would be the effect on the motor of having the high speed turned way out?? like maybe 2 or 3 turns out? I played with it a bit out on the water just to see if it would make a difference- think i was going out the whole time, it didnt change a thing and i wasnt sure what it was so didnt want to mess with it much, id say at most i put 3/4 turn out on it but may have alreay been out a bit to far. would that cause my problem? probably im guessing, would probably foul my plugs too wouldnt it?

 

[Bigkat650]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

pics of carbView attachment 152217View attachment 152218View attachment 152219View attachment 152220View attachment 152221

like i mentioned- the thing marked high speed just spins freely- is it supposed to be connected to the...:facepalm:...i think i just answered my own question but.. is the dial up top marked highspeed supposed to be connected to the dial/screw located under the throat of the carb in the middle(anyone understand that)? it is isnt it, think i might be missing something if so. let me know what you guys think

I'm not sure about others but I'm a little confused. Do you have the ability to take a video and show us what your doing and ask your question there? I think that certainly would clarify things up a bit for me... that is if you haven't figured it out already.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

just to clear it up for ya- if you look at the 2nd pic i posted its a good overall shot of the carb- you see the 2 adjustment knobs at the top of the carb?? left is low speed- right is high speed but the high speed knob is meant to be connected to the actual high speed screw located in the middle of the carb under the intake via a connecting rod that apparently isnt there, that way when you turn the high speed knob up top- its adjusting the high speed needle down below. the whole free spinning thing is just becuase the link is missing. Your adjustment procedure will still work for me- i just have to adjust the high speed needle directly instead of using that adjustment knob thats not connected to anything. Thanks again for the help- heres a pic with some lines added that should clear it up

I'm not sure about others but I'm a little confused. Do you have the ability to take a video and show us what your doing and ask your question there? I think that certainly would clarify things up a bit for me... that is if you haven't figured it out already.

 

[matth121]

Re: 61 Evinrude 40HP- no power/ burns tons of gas

Ok Guys- high speed needle was way out- i seated it gently and then backed out 3/4 turn, then i put another 1/8th turn so its set between 3/4 and a full turn- should be good for starting point- I'm going to guess that was the largest part of my problem and will be able to confirm that this weekend when i get out. When I bought this motor- I asked what the fuel oil mix was and was told 50:1. Today i seen a manual(thanks Bigkat) that shows 24:1 is the mix ratio. Thats a huge difference- i ran 50:1 the other day and it seemed ok other than the complete lack of power, but I'm concerned about the mix. What do you guys think?