1970 Evinrude 6HP will only run on full choke

[Crewdawg]

I have a question I am new to owning a boat, and I have a 1970 Evinrude 6HP motor, that will stay running on full choke and as soon as I start to push the choke in it starts to spit and loose HP and dies. As long as the choke is full out it stays running. Any ideas on what the problem would be or how to adjust the choke?

 

[JB]

Re: 1970 Evinrude 6HP will only run on full choke

You have low fuel availability.

It could be trouble with the fuel tank, fuel line, fuel pump or carburetor.

Your carburetor is the prime suspect. Start by getting a Service Manual (OEM only), then overhaul your carburetor as instructed.

 

[Rick.]

Re: 1970 Evinrude 6HP will only run on full choke

You could also try to give it a bit more fuel by turning your slow speed needle knob counter clockwise in 1/4 turn increments. You should find it will stop sneezing as increased gas becomes available. Once you find the spot it runs the best at the slowest speed pull the knob and re-install it a the 6 o'clock and your done. Best of luck. Rick.

 

[F_R]

Re: 1970 Evinrude 6HP will only run on full choke

Your high speed jet (orifice plug) is gummed up or dirty. It is in the very bottom of the carburetor, deep in the hole behind the hex head drain screw. Takes a special screwdriver to get it out.

 

[tx1961whaler]

Re: 1970 Evinrude 6HP will only run on full choke

If you don't want to fabricate a tool to take out the main jet, take off the hex drain screw on the bowl, and run a SOFT stranded copper wire (Not solid conductor) all the way through the main jet. Don't scratch up the inside of the jet, or you'll be hating life. That carb (I have the same 1970 6 Hp) must be absolutely clean to work. Any piece of crud will clog up those tiny passages. There is a small round metal plug about 0.5" in diameter on the top of the carb that hides some more passages. Take the plug out (a replacement plug is in the rebuild kit) and make sure those 4 little holes are clear.
Replacement fuel lines most likely needed. I had to replace all of mine last weekend. The outside of the lines looked fine, but the inside was turning to gunk and clogging the carb.