Evinrude 4 hp

sharkman

Seaman
Joined
Feb 23, 2005
Messages
55
Hello - last summer I picked up a 4hp Evinrude (s/n 4206s c 77806) at a garage sale, knowing it needed work, but figured I could get it running. After looking it over, and with help from iboat folks, I realized it had low compression and a stuck piston ring was the culprit. I sorted that out by removing the exhaust plate and poking at the ring and then replacing the plate etc. When tested, it ran initially, a little rough but it ran. However, it progressively ran worse and then I noticed in my test tank a large amount of oil/gas mix that seemed to be coming out of the exhaust? Very little blue smoke coming from the exhaust but lots of oil/gas in the water.... so much so the water was black. Any idea whats up?

Thx

Sharkman
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Evinrude 4 hp

dirty carb, carbon in the engine burning off. rebuild the carb, and then do a decarb with seafoam.
 

sharkman

Seaman
Joined
Feb 23, 2005
Messages
55
Re: Evinrude 4 hp

Thx tashasdaddy.....Gators for sure....awesome school and the bar in Treasure Island rocks too!

Did the carb rebuild before testing it...should I do it again after it all that carbon blew out?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Evinrude 4 hp

Oily water in the barrel. It's hard to believe there are still people out there that still don't know that's normal. However it will be worse if the motor is not running properly. All the usual possibilities exist. Compression, spark and too much fuel. We can guess all day, but you are the guy on site that needs to systematically check it out.
 

sharkman

Seaman
Joined
Feb 23, 2005
Messages
55
Re: Evinrude 4 hp

Imported - I have posted many times on this site and your response is the first of its kind. Not sure what your point is or why you felt it necessary to mention that you can't believe some people don't know that oily water in the barrel is normal. I think if you read my post you will see that I mentioned " a large amount of oil/gas" which would imply more than "normal".

Disappointed in the reply Imported, arrogant and unnecessary, some of us do not have the knowledge in the marine world as you purport to have, and we use this website to gain that knowledge. Questions like this, although obvious to some, are not so for the rest of us.

Sharkman
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Evinrude 4 hp

Feel better? Sorry you were offended. But the oil in the barrel question does come up every day. If you read the rest of the reply, you will notice that I said the condition will be worse if the motor is not running right. Would you rather I tell you that it's the carburetor, when I don't know if the ignition is OK or not? My point is that from here, we can only guess. We can help you through the troubleshooting process. But I'll bow out.
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: Evinrude 4 hp

Hi There. I refurbished a 1973 - 4 horse this winter for a friend. He had used the motor for one summer but always found it to be rough running. In the test barrel it too produced more than an acceptable amount of oil and what I found was it had a bad coil and so it was only getting spark in one cylinder. The plug wires were automotive type so I changed them out as well as both coils. I changed both because of their age and it was recommended by one of the Iboat fellows. I have to admit I was surprised how well it ran on just the one cylinder. Once I got it running well I filled the barrel with hot soapy water and ran it at a fast idle for about ten minutes and that helped clean up some of the oil deposits in the exhaust leg. I wouldn't recommend the soapy water proceedure unless you keep a constant monitor on the engine temp. as with the soap in the water it doesn't circulate as well as just plain water. Good luck with it . Rick
 

sharkman

Seaman
Joined
Feb 23, 2005
Messages
55
Re: Evinrude 4 hp

Rick - thanks for the info. I will look into the possibility of only one cylinder gettting spark. Would make sense as the premix from the non-working cylinder would go unburned into the exhaust leg and thru to the test barrel. Thanks again
 

spark knock

Recruit
Joined
Aug 4, 2003
Messages
4
Re: Evinrude 4 hp

Hello, i don`t know if i`am on right page .But i have 1976 evinrude 4 hp .I`am in the process of refurbishing it .My question is what side of the motor do you put the plugs.Fuel pump side or the other.Thx. Greg
 

moldeck

Seaman Apprentice
Joined
Jun 4, 2009
Messages
31
Re: Evinrude 4 hp

I had the same kind of issue, sounds like one cyclinder is not burning, my problem happened to be the head gasket, putting water into the cyclinder caused it to not burn and pump excess oil into the tank.
 

Wee Hooker

Chief Petty Officer
Joined
Sep 11, 2005
Messages
618
Re: Evinrude 4 hp

While oil in the water is "normal" you sould be able to run that motor in a barrel for a hour+ before it's noticable. ( I ran my 98 4 hp evenrude in abarrel ast night for 2 hrs and there wasn't more than a few teasponns in there. Not sure how bad your problem is. He're's my advice.
First, assume nothing. Check spark to both cyl and check the plugs to make sure both plugs are sparking regularly. If that check's out, do a compression check. ( you can buy a CHEAP tester or rent one from a auto parts store.) Both cyl's should be close in value. If not, you have a bad ring, leaky head gasket, cracked head........ . you need spark, compression and fuel to make an outboard run, by ruling out each of these on it's own, it's not hard to find the source.
hth
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: Evinrude 4 hp

Wires go on the fuel pump side. Start a new thread rather than restarting one two years old. Rick.
 
Top