ARRGHH!! Evinrude 70 H.P.

[15flats]

Re: ARRGHH!! Evinrude 70 H.P.

OK, tok the boat out to the lake today. The engine seems to run rough at low speed, and fine at higher speed. I.E., 900 RPM to around 1200 RPM, seems sluggish, and 1300 RPM up is much better. WOT is dangerous in this boat!! Front comes way up!!

 

[lonemust]

Re: ARRGHH!! Evinrude 70 H.P.

tuck the engine in closer to transom.. this will bring the bow down.. i learned the hard way.

 

[15flats]

Re: ARRGHH!! Evinrude 70 H.P.

Thank you lonemust,I have a Jack plate also, should it all the way down?

I need to figure out the idle\low power sluggishness as well. Used to give problems at high RPM, seems that is fixed (High RPM).

 

[tedious]

Re: ARRGHH!! Evinrude 70 H.P.

I have owned the same motor (1989 70) for one season. I have always had the low speed roughness / sluggishness that you have, and mine also runs great over about 1300 RPM. My motor will actually work fine at low RPM for about 30 seconds after you throttle down, then it gets rough - I always thought it seemed like it was starving for fuel. Based on some advice from another person here on iBoats, I replaced my idle air bleed jets to get a richer mixture, but I have not tested it yet.

Note that the carbs changed midyear in 89 - do you have the fixed or adjustable idle mixture carbs? If you have the adjustable version, you can try tweaking the idle mixture; on the fixed version like mine you'll need to change out the jets.

Link to thread describing idle air bleed change: http://forums.iboats.com/showthread.php?t=361234

Tim

 

[15flats]

Re: ARRGHH!! Evinrude 70 H.P.

Thanks for the input Tim, so far my rough idle at low speed does not cause the engine to stall, just rough and seems like it is flooding, because if I tap the key in (just tried it to see what would happen) it does stall. And I believe these carbs are fixed, but I ordered a VRO pump (mine broke) from ebay, and it came with the three carbs and primer. I will check those other carbs and see if they are adjustable or not.

John