Evinrude 55 Triumph (-68)

Mikko

Petty Officer 3rd Class
Joined
Aug 11, 2003
Messages
76
When accelerating I have to give a small choke before the engine takes a full trottle. After that it runs well. I have considered this just a minor problem and because it is very easy to give a small choke with automatic choke I have done nothing to fix it. With this information can anyone say what the problem is? I have come along with this problem over 15 years!<br /><br />Another question concerns the circulation of the cooling water. How can I be sure that water is circulating properly? I used the garden hose just to see that the engine is running well and it is very difficult (without the pee hole)to say weather the cooling water is circulating properly especially when the garden hose tool installed to the inlets spray water from everyhere.<br /><br />MV
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Evinrude 55 Triumph (-68)

Those motors have linkages to the idle mixture screws that like to be pulled down with gravity and lean-out the mixture. The packing dries out and loosens up against the needles and won't hold the needle there. I find that you don't have to constantly adjust those if the linkages aren't there. In other words, I'd remove everything relating to the external adjustment.<br /><br />Once the needle adjustments are right, they rarely need to be changed. The needles should all be turned out the same. Turn all of them in, count the turns to find an average, and adjust them all there. Since it seems that you're running lean, you might want to try about 1/8 turn farther out than the average.<br /><br />On the hose, if you get water gushing out of the prop, then the water pump is working. I know a lot sprays out from the muffs, but you can see if it's coming out from the inside of the prop from the back. I had a 60Hp 1970 very similar to your 55. I drilled and tapped into the top of the block where there was a flat spot right by the head and screwed in a fitting that allowed me to take 2ft of speedometer hose and route it out a hole I drilled in the corner of the pan for a pee indicator. Works well. Maybe yours has a plug there you can take out, or maybe there's one on the head. Usually 1/8" pipe thread.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Evinrude 55 Triumph (-68)

That problem is usually caused by having the throttle butterflies open too soon. The cam should start to touch and move the throttle roller when the scribe mark on the cam is aligned dead center with the roller.... not before!<br /><br />If the adjustable needle valves are loose on the retaining bushings at the front of the carburetors, replace those retaining bushings with the RED ones, OMC part # 315232.<br /><br />NOTE: Notice the mention about having more than one carb as listed below.<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br />(J. Reeves)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /> <br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.<br /> <br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /> <br />Note: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.<br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

Mikko

Petty Officer 3rd Class
Joined
Aug 11, 2003
Messages
76
Re: Evinrude 55 Triumph (-68)

Thank you, WillyBWright and Joe Reeves for your quick responses.<br /><br />MV
 

Mikko

Petty Officer 3rd Class
Joined
Aug 11, 2003
Messages
76
Re: Evinrude 55 Triumph (-68)

One more comment on this. When idling with shift in neutral the engine reacts well, but when moving, just to get the boat on plane it stalls without choke (difficult e.g. for start in water skiing!). When accelerating very very slowly I can sometimes get over "the breaking point". Does this mean that Joe's first suggestion is more likely the right one?<br /><br />MV
 
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