1967 Evinrude 6hp Fisherman starting problems

[mottt]

Hello out there, I first want to thank a lot of you out there who have posted replies to help other frustrated boat owners. I have been reading some posts which have helped me greatly.

I have a 1967 6hp Evinrude Fisherman - 6702
I got it at a yard sale for $50 with gas tank. The previous owner said that it ran 2 - 3 years ago. I drained the gas tank and cleaned it thouroughly and let it sit for 2 days to dry out. I got new gas and I built a mount for it and attempted to see if it would start with no luck. I have rebuilt the carb and set the HIGH speed to 1 full turn out and the LOW speed to 1.5 turns out. (to adjust the high i have to take the carb completely apart)

My dad came over a few days later and got the motor running after about 15 minutes of tugging on it. He had to keep messing with the choke and throttle to keep it running but IT RAN!!!

I have replace the old gas can, hose and gas - with 50:1

A few days later i could start the motor with a couple tugs and it would idle, but would not go into high RPMs. I tested compression with both plugs out and it is 90 on both cylinders. After 20 minutes of it idling, I did a gravity test with a funnel straight into the carb input (not the throat) and it would idle and run at high RPMs. Which would indicate a bad fuel pump.

I got a new fuel pump and attempted to test it again. I had as much trouble starting it this time as I did the first time. And it wouldnt stay at an idle.

WHAT IS GOING ON?

I read that these old motors once cold can suck air through old seals and still give you a good compression reading. When they get warm the seals expand and seal correctly. Is this true?

I am under the assumption that when the motor ran a idle and high speed when I did the gravity gas test was a coincedence.

I am at a stand still right now because I don't know of what more I can do with it. I want a pro to fix it, but im not sure if its worth the money.

Please help

 

[crxess]

Re: 1967 Evinrude 6hp Fisherman starting problems

It is not that complicated and would cost way to much for a professional in most cases.
First - you say you adjusted the high Idle, but have to take the carb apart to do so??
Are you referring to the jet behind the drain Screw? That would be a Fixed High Speed Orifice and should be fully screwed down.(No Adjustment)

Second - Low speed adjustment always start at 2-2.5 turns until you get it running. Then work it down Gradually, on the boat and under load to achieve best low idle.

Third - Did you use a rebuild kit - New gaskets - New fuel stop valve and nozzle.What is your float height?
Did you do the blow test? Carb upside down, no flow? upright air flow?
Did you wire clean the High speed jet?
Did you remove the soft plug and wire clean the tiny passages(low speed) into carb throat?

Fourth - Test fuel pump
Connect Tank - open tank vent
Disconnect hoes ar pump going to carb. and connect longer piece to pump with other end going to jar or can.
Pump fuel bulb. you should see fuel entering your container.
Briskly pull the start rope a few times. Fuel should pulse out the hose.
If no fuel is pumping, check the hole behind the pump for carbon blockage and clean if needed.

I'm betting on the carb still having issues. Had mine apart 3 times before I slowed down and did it right.

 

[mottt]

Re: 1967 Evinrude 6hp Fisherman starting problems

You are correct - I have to take the carb apart. I was under the impression the high speed needle was the high speed idle (behind the drain)

Where is the high speed adjustment then? And is the adjustment 1 full turn out? - this is probably my entire issue!

I will try the 2-2.5 turns on the low speed tonight
The fuel pump is brand new and works properly accourding to you test.
a blow test has been done with your specs.
The carb was dipped in Chem Dip over night and blown out with air. I dont see a problem with this but the high speed jet could need a cleaning again, once I know exactly what I am looking at.

Thanks for your input

 

[BF]

Re: 1967 Evinrude 6hp Fisherman starting problems

definitely start with a proper carb rebuild... get a kit with a new float. Those oldies used a cork float that could deteriorate and cause problems. Soaking and blowing out with air is not enough to clean out all the small orifices... as had been said, use a wire. You should also remove the welch plugs to properly clean the low speed orifices... A proper kit will include new plugs to insert afterwards. If you don't have a service manual yet, you should get one. It'll show how to set the float height etc... I'd also change the water pump impeller... it would be a shame to get it running and then have the motor be overheated/wrecked b/c a few dollar piece of rubber is old and dried out.

BTW, you did run it with the leg in a barrel or garbage can of water.... right?

Go to the FAQ's and read "awakening a sleeping outboard" good info there.

Good luck.

 

[mottt]

Re: 1967 Evinrude 6hp Fisherman starting problems

I will start to look at getting a new float. Any suggestion where?

Yes always ran in water, the impeller works but in the process of getting a new one.
The old float seems to be doing its job of allowing fuel into the carb then stopping flow once full. I was told that the float needs to parallel with the carb housing when the carb is apart. Is that correct?

 

[rossfree]

Re: 1967 Evinrude 6hp Fisherman starting problems

Hi Mottt,

Yes, on the float. With the carb upside down and the float resting lightly on the needle, it should be parallel with the carb.

And be sure the float is correct and not installed upside down. Check it carefully against the diagram.

To adjust the float, carefully bend the metal tab between the float and the hinge pin. Just a bit is all that should be necessary. This adjustment is important to proper carburation. It determines the height of the fuel in the bowl. The venturi creates a vacuum to draw fuel from the bowl. If the fuel level is too high, it allows extra fuel to be drawn in making for a rich mixture. If the fuel level is too low, it may not pull enough fuel in (too lean). Take your time and get this right. Then you can forget about it as you chase down other possible problems.

I just refurbed a 1965 6hp Evinrude engine. You only have a low-speed adjustment on your carb. They did away with the high speed adjustment for your engine and put in a fixed orifice near the bottom of the float bowl. Just screw that one down snug (don't over tighten anything .

Too answer the compression relationship...

On a two cycle engine, there are really two sides in play. There is the side above the piston where compression and combustion take place. Most people understand that side alright. But in a two cycle engine the crank case is also in play. While the piston is compressing the gases above it, it is creating a vacuum behind the piston in the crank case. This low vacuum draws fuel in from the carburetor through a set of pedal valves. The pedal valves are very thin metal valves that gently open to allow fuel into the crank case. This fuel/oil mixture lubricates the moving parts in the crank case.

When the compressed fuel above the piston is ignited, it powers the piston down. As it does, it slams the pedal valves shut, closing off the crank case from the carburetor and compressing the fuel mixture that previously entered.

As the piston approaches the bottom of its stroke downward, it exposes holes in the side of the combustion chamber. This allows the compressed exhaust gas to exit the chamber. A fraction of a second later, as the piston reaches the bottom of it's stroke, a second set of holes is exposed directly opposite the first. These holes allow the lightly compressed fuel in the crank case to push their way into the combustion chamber above the piston, further driving the exhaust gases out of the other set of holes.

It is here that two cycle engines are considered "dirty" because inevitably, some of the un-burned fuel entering the combustion chamber escapes through the exhaust holes before the piston can cover them on it's return stroke to compress the fresh fuel mixture. Not much mind you, but... well... there it is.

So the piston finishes compressing the new fuel mixture, all the holes are now closed, a fresh batch of new fuel is pulled in from the carburetor through the now open pedal valves and the process begins again.

All that being said, seals on the crank shaft, allow the crank case to pull a vacuum and then compress the fuel in it's dance to feed the combustion chamber. Leaking seals would hamper that process. Badly leaking seals could shut it down completely. A bent, dirty or broken pedal valve would also work against this process.

One more thing to note. Your engine is a two cylinder engine. But past the carburetor, you can consider it as two separate single cylinder engines. Because all that I said before happens completely separate from one another. Each piston has it's own sets of holes, it's own pedal valve, it's own separate crank case separated by an internal wall from the other and it's own set of electrics (coil, points and condenser). Knowing this can sometimes help you figure out just what problem you have. Is it a problem common to both cylinders of the engine or is it a problem common to only one side? Keep it in mind as you work through problems you encounter.

I hope I wasn't too long winded. By what you've written, I think you are on the right track with fuel being the culprit.

If you haven't yet pulled the flywheel and peeked at the points and coils, I suggest you do so. The coils on an old engine such as your (and mine) can crack and fall apart, killing the spark to the engine. Not something you want to have a mile from the dock. It's worth the effort to pull the flywheel.

Best of luck!

Ross