57' evinrude big twin 35 carb ajustments

whitty6071

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i have got it to idle for maybe 30 seconds. i have the low speed about 1 1/2 turns from bottom and high speed set for maybe 2 turns. it seemed to idle stronger with the high speed open more. the pressure keeps dropping on the primer button on gas tank. maybe air leak somewhere? any help please. what are the recommended carb settings. i live in minnesota so its quite cold and dry right now. i dunno if that will effect standard carb settings. thanks
 

lindy46

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Re: 57' evinrude big twin 35 carb ajustments

Carb probably needs cleaning/rebuilding. High speed needle should be open only about 3/4 turn to start. Primer button just pumps gas initially into the fuel bowl/carb. Once running, pressure from the engine keeps gas flowing into the carb. Does your tank hold pressure? If motor has been running for a few seconds, try loosening the gas cap. Should get a good hiss of pressurized air come out. If no hiss, you have an air leak somewhere. That motor has no fuel pump and relies on the pressure to push gas out of the tank to the carb.
 

bktheking

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Re: 57' evinrude big twin 35 carb ajustments

That has the twin line fuel tank? Pressure is supplied from the primer just to start the motor, pressure is maintained by the the feed coming from the motor, not the carb. Inspect lines and check the cap, they have to be extremely tight to seal. The primer pressure shouldn't drop, sounds like a leak to me. Grab a spray bottle with soap and water and spray around the tank at the top to detect a leak. They can also leak at the seams at the bottom of the tank, especially is there is rust that can be seen on the seam.
 

whitty6071

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Re: 57' evinrude big twin 35 carb ajustments

i cleaned the carb. it was actually spotless. i dont hear any air leaks. i opened the cap after it killed from idle, and it did hiss. i will try those new settings on the needles. i use the same tank on a old johnson 10hp seahorse and it doesnt have any problems. i just got this motor for 25$ and cleaned the points last night and it fired up today. thanks for the help i will post if i have more problems.
 

bktheking

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Re: 57' evinrude big twin 35 carb ajustments

What's compression like? Sounds like maybe the needle is sticking, typical description of "ran for 30 seconds".
 

whitty6071

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Re: 57' evinrude big twin 35 carb ajustments

it has alot of compression i dont know the exact amount, I dont have a tester. what do i start out on the slow speed adjustment?
 

whitty6071

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Re: 57' evinrude big twin 35 carb ajustments

there is no kill switch. how do u kill it once its running. i had i running just now and decided to turn it off and i didnt know how. i just pulled the choke out and it revved a bit higher then killed. there is a black wire coming from the coil and it leads to nowhere. i tried grounding it when the engine was running, and nothing hapened. any help on that?
 

bktheking

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Re: 57' evinrude big twin 35 carb ajustments

DOn't know that specific motors, usually 1 black wire from each point touched together will shut it off , grounding out the coils.
 

freddyray21

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Re: 57' evinrude big twin 35 carb ajustments

the kill switch on those was a wire running from each set of points to a switch. Push the switch and the points grounded out and killed the motor. It may not have a kill switch however if it just has one wire coming out. That wire would go to a runaway vacuum switch on the side of the motor. If the motor started running away the vacuum would ground one set of points keeping it running on one cylinder until it slowed down enough then the vacuum would quite and the cylinder would pick back up.
 

rolmops

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Re: 57' evinrude big twin 35 carb ajustments

The '57 does not have a kill switch.You stop the engine by choking.The one wire coming out should go to a mercury runaway engine kill switch
You can open the glas fuel filter bowl and clean it.then try to run the engine without the filter and keep an eye on the bowl.If you see the fuel level go down,it is time to check the fuel line.Very often there is some dirt in the connectors.This will severely impede fuel flow.make sure they are clean.
You can take a bottle with fuel with a hose connected to the fuel bowl and hold it above the engine.If the engine runs well when the fuel is gravity fed,you know that you have a problem with your fuel supply that you will have to trouble shoot.
keep us informed.
 

lindy46

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Re: 57' evinrude big twin 35 carb ajustments

there is no kill switch. how do u kill it once its running. i had i running just now and decided to turn it off and i didnt know how. i just pulled the choke out and it revved a bit higher then killed. there is a black wire coming from the coil and it leads to nowhere. i tried grounding it when the engine was running, and nothing hapened. any help on that?

Motor was designed to kill by choking. You can add a kill circuit easily. Someone may have already done it if you see a black wire coming from under the flywheel. There should be a second wire coming from under the flywheel and going to the cut-out switch on the port side of the engine. That wire would go to the points which control the bottom cylinder, and shut down that cylinder if a runaway happens. Install a second wire to the other set of points, and add a jumper wire to the cut-out circuit and you have a kill circuit. Just touch the two wires together to ground out both sets of points and kill the engine.
 

lindy46

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Re: 57' evinrude big twin 35 carb ajustments

it has alot of compression i dont know the exact amount, I dont have a tester. what do i start out on the slow speed adjustment?

1-1/2 turns out is correct for the slow speed. Once on the boat, run at WOT and adjust the high speed needle to optimum. Then idle her down and fine-tune the slow speed.
 
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