1970 6hp Evinrude Fisherman(need help)

[trollfish]

I have a 6 horse evinrude that is not feeling well.It starts on the second pull and when out of gear runs as smooth as a top. When in forward gear it runs smooth till about half throttle. After half throttle it bogs down with no power. Sometimes it will spit and sputter and if I hit a sweet spot in the twist it will rev out and push like it is supposed to. Thought problem was carberator flooding. Took it all apart and cleaned it. It was pretty clean to begin with. Replaced float and gaskets. Still doesn't go. Checked points,plugs, condensors etc. All good and working properly. Checked compression 75psi on bottom,73psi on top. Now I am truly lost. When it revs out it planes my 13' jon just fine, but you never know when it will just take off. Plugs are replaced and are not fouling out. Motor is spitting water as it should, temp is not the issue.When it bogs down and loses power, it gets a deep sound to it like the choke is on half way. Any help would be appreciated. I'm on a tight budjet and can't afford a shop. Thanks.

 

[jegervais]

Re: 1970 6hp Evinrude Fisherman(need help)

When it acts-up, does it do it consistently? If so, get yourself a pair of heavily insulated pliers and do a "cylinder drop test". For safety considerations, this would be best performed tied to a dock. Run the engine at the problem rpm - with the insulated pliers, remove one spark plug lead. If the engine stalls, re-install the lead and re-start/ pull the other lead. Which ever pulled lead does not change sound or rpm, is the "bad" cylinder. Then you can focus on the coil, points or whatever for that 1 cylinder.<br /><br />-John

 

[almost retired again]

Re: 1970 6hp Evinrude Fisherman(need help)

Trollfish,<br />You might check the small holes at the top of the throttle throat just in front of the throttle plate, these are the intermediats that are supposed to take up the dead spot from idle to full throttle. If they are plugged it can cause the same problem.

 

[alcan]

Re: 1970 6hp Evinrude Fisherman(need help)

Hi trollfish<br />I have a couple of ideas. First check the link & sink. Make sure the roller or rub block on the throtle arm is not real worn. This is called the cam follower. If they get grooved bad, you can't adjust properly.<br />Your comperssion readings sound a bit low to me. You might want to try a decarb and see if those numbers will come up a bit. Do make sure your fuel pump is working and the fuel line connectors are in good shape. Tank vent open? Let us know how you make out.

 

[Chinewalker]

Re: 1970 6hp Evinrude Fisherman(need help)

Sounds like ignition to me. Try John's test and go from there. Dollars to donuts you've got a bad condenser or a problem with the points (cleaned and gapped at .020"). Coils from that era are usually pretty good still, as they figured out the cracking problem by then... You can get a set of two points/condensers for under $20.00 and you won't have to worry about them again for years to come...<br />- Scott

 

[trollfish]

Re: 1970 6hp Evinrude Fisherman(need help)

Did the drop cylinder test, motor runs a little rough but doesn't shut down. It has plenty of fire. I felt it! Not enough insulation on the pliers. Points are gapped and clean. Did not find two holes when I cleaned carb. Just one in front of throttle plate that goes to the rich/lean needle. Will take it off and look again. Will also decarb the motor. Thing is, everything is clean. Guy I bought it from took real good care of it. When I did the carb the first time, the cam follower was worn. I built it back up with epoxy as well as the mating piece on the throttle control. It is smooth all the way across and mates perfectly. I'll go over it one more time and check everything again. Thanks for the pointers.

 

[jegervais]

Re: 1970 6hp Evinrude Fisherman(need help)

Trollfish-<br /><br />When you did the cylinder drop test, did either cylinder NOT make a difference (i.e. engine rpm didn't change)? The point of the test isn't the amount of "fire" (smarts the 'ol elbow doesn't it) - it's to determine if one cylinder isn't pulling it's share of theload.<br /><br />-John

 

[trollfish]

Re: 1970 6hp Evinrude Fisherman(need help)

Pulling either plug wire had the same affect. It ran a little rougher than with both of them hooked up,but didn't see any difference from one cylinder to the other. I hope I said that right.<br />I did not have it in gear when I did this cause i was by myself. Is that the way it needs to be done? <br />I'm still not sure what it is doing. It sounds like it is flooding out, but it is not. When I open the throttle all the way from say mid range it gets this sound like a truck in low 4wd. I dont see any gas in the water and the plugs don't foul out. <br /><br />The elbow still smarts a bit!