Year of 4 hp evinrude and idle help

gatorbus

Cadet
Joined
Jan 21, 2008
Messages
14
I am the new owner of a nice older 4 hp Evinrude that has a model and ser # 4006E-E03798 and I was wondering if anyone can tell me the year. This motor will only run with the choke pulled out about 1/3 of the way. Can someone steer me in the right direction to get it running better. Also, I was told this engine is the weedless model. The lower unit seems to have a long skeg with the prop on a angle. Are these motors good Running? Any comments or suggestions will be greatly appreciated.

Thank you
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: Year of 4 hp evinrude and idle help

If you need to choke it to get it to run then at normal operating condition it is starving for fuel. It could be a fuel pump issue but most likely the carb is dirty and needs to be taken apart and cleaned and put back together (rebuild)

Yes, the angled props are the weedless models but I did not know the 4 was made that way, I thought only the 3 was but obviously you have one :)

And the 4's that came from the 50's and 60's 3's are excellent engine and were basically the same for about 3 decades or so...
 

jay_merrill

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Dec 5, 2007
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5,653
Re: Year of 4 hp evinrude and idle help

I think it is a 1970. Anyone else care to confirm?

Sounds like the carb needs to be rebuilt. Since the motor is new to you, it wouldn't be a bad idea to check/replace the points, plugs, condensors and coils. Tuneups on the small OMC motors of that vintage also call for replacement of the head gasket. This is simple to do and you can clean the carbon deposits off of the piston crowns and inner head surface, while you have it apart. It might not be a bad idea to do a compression check before and after you pull the head, however. While you are doing all of this, don't forget to replace the water pump impeller and lubricate all the appropriate fittings and parts.

These are great little motors. I have one that I don't use much but I find it pretty hard to tell the difference in thrust compared to a 6hp of the same approximate year. Really, the bigger difference is the lack of FNR gear capability with the 4hp.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Year of 4 hp evinrude and idle help

Gator, have you tried the obvious? Give the lower (high speed) knob a tweak to the left, toward richer. That could be all it needs. Then fine tune both as described above.

They are fine motors.
 

jay_merrill

Vice Admiral
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Dec 5, 2007
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5,653
Re: Year of 4 hp evinrude and idle help

Yup, that would be a good idea. I guess the rest of us forgot to start with the basics!
 

gatorbus

Cadet
Joined
Jan 21, 2008
Messages
14
Re: Year of 4 hp evinrude and idle help

Thanks for the advise folks. I plan to mess with it this weekend.
I will keep you updated.

Thanks again for your help.
 

gatorbus

Cadet
Joined
Jan 21, 2008
Messages
14
Re: Year of 4 hp evinrude and idle help

Hey guys,

I need some more help. I took the fuel pump apart to check the diaphragms and I can't seem remember how it goes back together. It is a lot more complicated than I thought. Is there anyone who can post a pic of the fuel pump assembly or talk me through reassembly. Any way the diaphragms look good. I am desperate now.

Thanks again
 

dukboat

Seaman
Joined
Dec 13, 2007
Messages
52
Re: Year of 4 hp evinrude and idle help

You can go to crowley marines web site and get diagram of the fuel pump, just type in your model number and they have a diagram of the whole motor. I have a 62 3 HP basicly the same motor , they run great and are easy to work on.
 

dukboat

Seaman
Joined
Dec 13, 2007
Messages
52
Re: Year of 4 hp evinrude and idle help

Heres a diagram
 

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gatorbus

Cadet
Joined
Jan 21, 2008
Messages
14
Re: Year of 4 hp evinrude and idle help

My buddy had a spare fuel pump on one of his old junker motors, it was the exact one, whoo hoo. I put it together and it fired right up and purred. There was not a whole lot of water pissing out so I touched the cyls and they were very hot so I shut it down. Looks like a water pump will be my next project.
 

gatorbus

Cadet
Joined
Jan 21, 2008
Messages
14
Re: Year of 4 hp evinrude and idle help

Hey guys another question. I put a new impeller in it still does not seem to be pumping much water and is still getting hot. Is the fact that I have the motor in a 5 gal bucket causing this? Also is there a thermostat that may be clogged? Thanks again.
 
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