Fuel problem with 1977 55 HP Evinrude

NCTiger

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May 11, 2010
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7
I recently aquired a 14' McKee with a 77' 55 hp Evinrude. It ran fine when I purchased the boat... but when I got home, not so much! I towed the boat 150 miles, and when I got home I notice oil/fuel leaking from the cowling. When I put it in the water the engine would turn over fine, but it seemed like there was no spark. After a couple of tries I got it to briefly start with the warn up lever engaged. I shot some carb cleaner into the carb, and eventually was eventually able to get motor running in gear. I had it a wide open throttle, and the boat was only running about 10 knots, and not on plane. As soon as I brought the throttle back more than 1/2 way it would die. The previous owner told me that he had the carbs cleaned and a new fuel pump installed earlier this year, and showed me the receipt for the work. I am thinking it may be a fuel filter issue? Anyone have any suggetions on where to start?

A couple other things:
-Compression on both cylinders is 140
-The primer bulb is new, and remained hard throughout
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Fuel problem with 1977 55 HP Evinrude

Have engine in the normal running position. Remove the carbuiretor face plate so that you can see the carburetor throats. Observe the carburetors while you pump the fuel primer bulb up hard.

If fuel flows out the carburetors, either the carbs are fouled or the float level is set wrong.

Check spark..... Remove spark plugs, rig a tester whereas you can set a 7/16" gap for the spark to jump. Crank engine and obsrve spark. The spark should jump that gap with a strong blue lightning like flame..... a real SNAP! No tester? See the following.

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:


..........X1..........X2

.................X..(grd)

..........X3..........X4

Let us know what you find.
 

NCTiger

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May 11, 2010
Messages
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Re: Fuel problem with 1977 55 HP Evinrude

Thanks Joe! When looking at the at the carburetor throats, should the the throttle be wide open? Where exactly should I be looking for the fuel to be coming from?
 

Joe Reeves

Supreme Mariner
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Feb 24, 2002
Messages
13,262
Re: Fuel problem with 1977 55 HP Evinrude

Just leave the throttle wherever it is..... doesn't matter. If flooding, fuel will flow out of it, you won't need to look hard for it as it will be obvious. If no fuel flows out of the carburetor and the fuel primer bulb is hard..... th carb isn't flooding.
 

NCTiger

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May 11, 2010
Messages
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Re: Fuel problem with 1977 55 HP Evinrude

I just got a carb kit today in the mail. I read the instructions that came with it, and they say to back the slow speed needle out 1 turn. I just went to go remove the carbs off the outboard and noticed that the slow speed needle was tightened all the way down. It was hard to even loosen it! Is it possible that this was causing all my problems? What happens when you have the slow speed needle tightened all the way down? It was the same on both carbs. Any help would be appreciated, before I teat the thing apart!
 

NCTiger

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May 11, 2010
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Re: Fuel problem with 1977 55 HP Evinrude

Joe, I checked to see if there was fuel leaking out of the carbs. When pumped the fuel bulb will stay hard, and I didnt see or smell any fuel leaking out.
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Fuel problem with 1977 55 HP Evinrude

Some of those engines had fixed brass idle jets, others had slow speed adjustable needle valves. Either of them would be located at the top front area of the carburetor.

If fixed idle jets, there would be a blocking screw with a red fiber washer in back of it at the top front area of the carb. If adjustable needle valves, same location and should be obvious.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

The carbs may have been cleaned at one time BUT it sounds like they need cleaning again.
 

NCTiger

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May 11, 2010
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Re: Fuel problem with 1977 55 HP Evinrude

So I pulled the carbs off and cleaned them yesterday. Took the boat down to the ramp today and.... it started right up! Idled perfect and took off at wide open throttle. After an hour or so of running the boat, I pulled the throttle back to idle and it died (did this 3 or 4 times during the previous hour with no problem). I couldnt get it restarted, and it was showing the same symptoms as before. So, I guess some crude broke free from somewhere and clogged up one of the carbs again? I really hope that is the case anyways! Thanks for the help Joe!
 

NCTiger

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May 11, 2010
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Re: Fuel problem with 1977 55 HP Evinrude

Cleaned out the carbs again, and it still wont start. I checked for spark, and found that I have nothing on either cylinder. I am thinking that it could be the ignition switch since there is no spark on both cylinders. What is the best way to test?
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Fuel problem with 1977 55 HP Evinrude

Disconnect the large RED electrical cable at the engine. Now, check spark (with the plugs removed) by jumping the starter solenoid.

If you now have spark with the RED plug disconnected BUT do not with it connected, replace the ignition switch.

If still no spark with the RED plug disconnected, the problem is usually a blown powerpack.

If a bad powerpack, with the key ON but engine NOT running, remove and check the black/yellow wire at the powerpack for voltage. If there is even a micro volt present at that wire's terminal, replace the ignition switch along with the powerpack. There must be no battery voltage applied to that black/yellow wire as that will destroy a powerpack.
 

NCTiger

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May 11, 2010
Messages
7
Re: Fuel problem with 1977 55 HP Evinrude

Today I replaced the power pack with a new one from iBoats. The evinrude fired right up and ran perfect! I didnt find any voltage leading from the ignition switch... so hopefully that is not what caused the power pack to go bad. Thanks for all the help!
 
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