'71 Johnson 6hp 2-stroke

[AlumaDude]

So, I finally took the "new" old boat out yesterday. Trailer towed well, truck got 21mpg in the process, and the wife and I had a great time "exploring" coves and hidden areas that show signs of great fishing. The boat was watertight, rode dry, and with only a few inches draft we got into some very cool spots (pictures to come). HOWEVER, after about 2 hours of running around, the motor quit cooperating. Wouldn't pull start, wouldn't idle, nothing. I managed to limp it back to the dock (without rowing) by holding the throttle at WOT and manipulating the choke (choke had to be almost fully "on". When I would do this it would run fair and almost at proper high RPM??? What the HELL??? The plugs weren't fouled, it didn't SEEM hot, NOT outta fuel? Anybody have any ideas? I'm planning on tearing into it this week, and I'm not sure where to start. THANKS for ANY HELP!!!

-model: 6R 71G

 

[danmyersmn]

The air intake valve on the tank is closed or plugged thus not allowing proper air/fuel mixture because of the lack of fuel pumped?

 

[Loggerhead Mike]

If you had to choke it to keep'r running she was running lean. make sure your float isnt sticking ect

 

[Whoopbass]

Sounds like a carb issue.
Disassemble carb then soak it overnight in cleaner. I use paint thinner for oil based paints. Blow it out with compressed air and reassemble.
Set your low speed jet about 1 1/4 turns out (top knob). Turn the knob down until it starts bogging some and then turn it back slightly until it smooths out.

 

[Cheech]

Carb stuff, fuel filter or just old & dirty.

I ran this "Evinrude Johnson Engine Tuner" stuff through TWO engines that weren't running great and they both were like new motors when this was done. I ran the can as directed, with two heat up cycles and a cool-down and a waiting period. After doing it I put new plugs in the 2-stroke engines (a 9.5HP and a 90HP). Between the running - cleaning - waiting - running process and the new plugs these two engines really ran great.

Can't hurt.

Evinrude Johnson Engine Tuner - Standard Spray Can
Price: $10.85
"For use in engine tune up to remove gum and varnish build up, excessive carbon deposits from rings, pistons, valves and ports. Spray through air intake of 2 and 4 cylinder engines for improved performance. Not to be mixed with fuel."

A marine guy in the boat service area at Cabela's turned me onto the stuff. You can find it online too (https://www.usboatsupplies.com/mm5/merchant.mvc?Screen=PROD&Store_Code=USBS&Product_Code=777185&Category_Code=BEJE)