I have a 1983 Evinrude 75 HP motor on my 16'7" Whaler that begins to stall out when I bring the trottle forward. If you tap the choke the motor catches up and goes but if you compress the primer bulb it still stalls so I don't think it is the fuel pump. I have had the carbs rebuilt twice. After the second time the motor ran great the first trip out and then went back to the same problem during the second trip. The compression is good, 140 on all 3 cylinders. Plugs look good. New fuel tanks, fuel line and primer bulb to motor and fuel filter is clean. WOT gets me to about 30 knots depending on conditions. RPM guage doesn't work. Ocassionally the motor will bog down and then catch back up. Also there is an occasional misfire at idle speed. Since the last carb rebuild (june 2004) I have been going out about once a week and just tapping the choke when I accelerate. Any ideas?
I have a 1979 70hp johnson that does the exact same thing,it boggs coming out of the hole but catches up after a tap on the choke button and takes right,lots of top end,idles fine with slight misses.These guys say that the low speed jets might be dirty and in need of some carburator cleaner.I am going to clean these tonight and see...
bumping the choke successfully assures you that its a fuel problem. you say the carbs were rebuilt. were they just taken apart and cleaned? if so u still have sticking float valves in which case cleaning may be a temporary solution but is not addressing the problem. best thing for you to do is get a manual and rebuild the carbs yourself with new parts. Its not difficult or expensive. good luck
Both times they were completely cleaned and new carbkits installed. Gaskets, etc. I finally bought a manual and will probably try to rebuild them myself. Hopefully third time is the charm. I may also try replacing all the fuel lines between the carbs. They seem to be in good shape but you never know.
71 whaler,i removed the fuel line from the tank and removed the connector on the end,put the line in a bottle which had carburator and injector cleaner mixed with some gas and i added some pre mix oil to keep things lubed.I started it in the yard and let it idle until the mixture was gone.Took it to the lake and it went like hell,no bogging left,none what so ever,but like stairliftoheaven said,it may be temporary but it sure works for now.Good Luck!!!
Yes the bulb does get firm when priming. I also replaced the bulb and fuel line before the carbs were rebuilt for the second time. I will try replacing the fuel lines between carbs and if that fails then I will try the cleaning method sugested by Polly. Last resort I will clean the carbs for the third time.
I have an 85 Johnson 235. I had the same problem, including the same primer situation. I bought a can of OMC carb cleaner, teh kind you lug into the primer port. Followed the directions, and it fixed the problem.
Guys - I think it is something else. My 77 70HP was doing the same thing. It was the timer base not advancing with the throttle linkage. Check to see if the timerbase is being pushed all the way forward as the throttle opens up. There is no accelerator pump in these units. For it to get enough fuel, it advances the timing and revs up the engine so the high speed jets work. If the timing doesn't advance, it "runs" out of fuel. That is why tapping the choke helps for a second.Stiff wires were keeping my timing from advancing and
83 Evinrude 75HP, stalling at acceleration
Linear Mode
