old 4hp evinrude, need info

someone11

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I have an old 4 horse envinrude motor that needs worked on. It missed pretty badly except for in full throttle. Im not much of an outboard motor person, but I do know snowmobile engines pretty well. But any information on this motor is greatly appreciated. And any idea what would cause the missing? Would it be a timing thing?

heres some pics

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film495

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Re: old 4hp evinrude, need info

Does it miss on both cylinders or just the bottom one? I have a 3hp that looks almost exactly like that motor and mine skips sometimes on the bottom cylinder and I'm trying to identify why. Maybe we have the same basic problem.
 

Rick.

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Re: old 4hp evinrude, need info

She's a beauty! The pictures were great and very helpful. Your spark plug boots don't look so good there the tape is. You could have leakage there and that would cause a miss. Your slow speed lean/rich, if adjusted too lean, will cause it to sneeze which will seem exactly like a miss. With the motor running and warmed up turn the Slow Speed knob out (counter clockwise) 1/8 turn at a time and wait a few seconds between to see if it clears up. At the back it appears as though you have a leaking head gasket by the look of the top starboard bolt. You can re-torque the head or you could remove it and replace the gasket. I would probably re-torque it first. I have a 71 and yours looks very similar so I would expect yours in the range age wise. A few years newer and it would have a gear shift. I love your throttle control but I must tell you not to run it at fast throttle unless it's on the boat. Never on muffs or a barrel. All and all it looks to be in good shape. At the top of this forum there is a "Top Secret File" you should have a careful look through. Lots of good information there. Best of luck. Rick.
 

someone11

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Re: old 4hp evinrude, need info

She's a beauty! The pictures were great and very helpful. Your spark plug boots don't look so good there the tape is. You could have leakage there and that would cause a miss. Your slow speed lean/rich, if adjusted too lean, will cause it to sneeze which will seem exactly like a miss. With the motor running and warmed up turn the Slow Speed knob out (counter clockwise) 1/8 turn at a time and wait a few seconds between to see if it clears up. At the back it appears as though you have a leaking head gasket by the look of the top starboard bolt. You can re-torque the head or you could remove it and replace the gasket. I would probably re-torque it first. I have a 71 and yours looks very similar so I would expect yours in the range age wise. A few years newer and it would have a gear shift. I love your throttle control but I must tell you not to run it at fast throttle unless it's on the boat. Never on muffs or a barrel. All and all it looks to be in good shape. At the top of this forum there is a "Top Secret File" you should have a careful look through. Lots of good information there. Best of luck. Rick.

Thanks for the fast reply! What are the torque specs? I decided just to go ahead and start wrenching on it without a manual. I just took the carb off. It looks surprisingly clean, although the float looks interesting, compared to what ive seen on sleds. Where would be the best place to get parts? At the local boat shop? More pics...

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F_R

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Re: old 4hp evinrude, need info

Now that you messed with the carburetor, go to an Evinrude dealer and get a repair kit for it. The kit from a dealer will have a new fuel-proof float in it. Aftermarket kits don't.

After you put the carburetor back together, check out the ignition system. Ignition causes missing, carburetors don't. (except for lean sneezing). Those taped-up wires look mighty suspect. Or could be dirty breaker points, etc.
 

someone11

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Re: old 4hp evinrude, need info

Now that you messed with the carburetor, go to an Evinrude dealer and get a repair kit for it. The kit from a dealer will have a new fuel-proof float in it. Aftermarket kits don't.

After you put the carburetor back together, check out the ignition system. Ignition causes missing, carburetors don't. (except for lean sneezing). Those taped-up wires look mighty suspect. Or could be dirty breaker points, etc.

A repair kit or a rebuild kit? How much will one run? I untaped the wires to see why they were taped in the first place, they dont look too bad, ill get pics next time I go out. I took the flywheel off, points look good and clean, but ill clean them up just in case.
 

F_R

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Re: old 4hp evinrude, need info

A repair kit or a rebuild kit? How much will one run? I untaped the wires to see why they were taped in the first place, they dont look too bad, ill get pics next time I go out. I took the flywheel off, points look good and clean, but ill clean them up just in case.

Repair, rebuild, just words. It is a "Carburetor Kit". Depends on the year, 1965-67 uses part number 439071, 1968-78 uses part number 398532. Both are around $25.

You can't see a defect in spark plug wires where it arcs through unless it is downright terrible. But grab hold of it and you will find out. Naw, forget I said that, you might have a bad heart or something.
 

Rick.

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Re: old 4hp evinrude, need info

F_R is right as rain about ignition causing missing but a lot of people do get sneezing mixed up with missing. Your carb. float looks like it's a candidate for replacement. I bought an OMC kit last fall and it did come with a new cork float. I was a little surprised it was still cork. I'm from Canada and would not venture a guess what you will pay. I don't remember what I paid but it made a real difference to my engine. Rick.
 

Bign71

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Re: old 4hp evinrude, need info

does this motor have a lever on the side for throttle control and doesnt have reverse or neutral ? does the motor spin 360 degrees ? I just got a 1966 5 hp sea horse that looks just like your motor except for the color and the lever on the side is opposite ...

mine missed a bit i pulled the fly wheel and cleaned the points..and she runs beutiful... i agree with the spark plug wires they look a lil old.. the Carb kit in my part of the country (florida) is 16.95 very easy to install.

good luck with her brother
 

someone11

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Re: old 4hp evinrude, need info

does this motor have a lever on the side for throttle control and doesnt have reverse or neutral ? does the motor spin 360 degrees ? I just got a 1966 5 hp sea horse that looks just like your motor except for the color and the lever on the side is opposite ...

mine missed a bit i pulled the fly wheel and cleaned the points..and she runs beutiful... i agree with the spark plug wires they look a lil old.. the Carb kit in my part of the country (florida) is 16.95 very easy to install.

good luck with her brother

Yeah, it has the throttle on the side. No reverse or neutral and it does spin both ways. Looks like my next step is a carb rebuild kit, and maybe a new gasket kit, I think theres another gasket leaking. more pics..

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Rick.

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Re: old 4hp evinrude, need info

Yes, my first post says, "At the back it appears as though you have a leaking head gasket by the look of the top starboard bolt. You can re-torque the head or you could remove it and replace the gasket. I would probably re-torque it first."

I don't have my manual at home but 240 inch ponds seems like the right number by memory. Rick.
 

Rick.

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Re: old 4hp evinrude, need info

Looked at my 71 - 4HP manual this morning and it says 60 to 80 inch pounds. Quite a bit less than I thought. Rick.
 

someone11

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Re: old 4hp evinrude, need info

Looked at my 71 - 4HP manual this morning and it says 60 to 80 inch pounds. Quite a bit less than I thought. Rick.

Are you sure its inch pounds? and not foot pounds.

Where can I find a production number on the motor, so I can figure out exactly what year it is?
 

rolmops

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Re: old 4hp evinrude, need info

Your carburetor float looks funny but it still works or your engine would flood all the time.The little push button on the bottom of the bowl will allow you to drain and winterize the carb without having to take things apart.
The missing and/or skipping may well be caused by the plug wires and boots.An easy way to check this is by running the engine in a barrel in the dark with the cowling off.If you see the sparks flying you know that you must replace the plug wires and boots with new MARINE wires and boots.The high and low needles on your carburetor may need adjustment.and while you have the flywheel off you want to make sure that the points open at 0.020 inch.
It is my experience that usually very little goes wrong with these little outboards.Usually a little bit of adjustment and some "seafoam" in the fuel solves 90% of your troubles.
Good luck.
 

someone11

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Re: old 4hp evinrude, need info

Your carburetor float looks funny but it still works or your engine would flood all the time.The little push button on the bottom of the bowl will allow you to drain and winterize the carb without having to take things apart.
The missing and/or skipping may well be caused by the plug wires and boots.An easy way to check this is by running the engine in a barrel in the dark with the cowling off.If you see the sparks flying you know that you must replace the plug wires and boots with new MARINE wires and boots.The high and low needles on your carburetor may need adjustment.and while you have the flywheel off you want to make sure that the points open at 0.020 inch.
It is my experience that usually very little goes wrong with these little outboards.Usually a little bit of adjustment and some "seafoam" in the fuel solves 90% of your troubles.
Good luck.


Alright, thanks for the info. Ill check the point gap tommorow. Im pretty familiar with points, I have an old sled that has points.

Again, is there any production number stamped on the motor to tell what year it is? It would be helpful to know when I go to buy parts for it.
 

Rick.

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Re: old 4hp evinrude, need info

I've been away. There should be a tag on the transom mount bracket, port side, with a model and serial number. Rick.
 

1946Zephyr

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Re: old 4hp evinrude, need info

Nice little motor. I have one just like it in my shed. It looks like someone went through the expense of puting new coils in it. The plug wires look a bit rough though. Like rolmops said: run it in a barrel at night and see if you see any arcing from the wires. You might also check the condition of the connections in the plug boots too. Sometimes, the coils inside the boots can rust a bit and lose connectivity with the wires. When you pull them apart, make sure the sharp "L" goes through the wire dead center, or it may miss the wire in the center and not deliver spark to the plug.:cool:
 

someone11

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Re: old 4hp evinrude, need info

The model number is: 4606M And the serial number is: E0003739
 
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