115hp johnson

[ed]

" Joe,

In regards to my earlier posting that i was not able to lower the idle speed, the culprit was a disconnect recirculation hose. it had allowed air to be sucked into the engine. the brand new recirculation hose from Sierra cracked and fell out.

finally ran both the engines in the bay this morning. they ran great!. i have to say that it is not possible without your help. we burn about 10-15 gallons of gas in about 2 hrs running them just above idle to 3500 rpm. is there a particular RPM range that is most efficient for these 82 Johnson's?

i needed to get the bow down and moved the guide pin on the lower unit bracket to the lowest setting. the engine came down a little but it is not resting on the pin. it is ok?

thanks again. i'll take some pictures next week and send them to you. "

[joereeves]

"Ed.... Strange that a new hose would crack and fall off, but weird things do happen.

The rpm range.... you would want the engines to develop, at full throttle, a rpm that would be as close as possible to the factory specified full throttle operating range of 5500 rpm (1982 115hp Evinrude/Johnson), but NOT TO EXCEED that figure. You're no doubt aware of the fact that a improper propeller would cause a engine to not obtain the proper rpm, which in turn would waste fuel.

The fuel consumption for twin 115hp engines sounds about right to me. However, I must admit that I've lost track of that aspect of boating. Hopefully someone else with broader knowledge of that subject will chime in.

The location of the tilt pin/guide pin/reverse lock pin should be the hole closest to the boat (all the way in) as you do have PTT on both engines. If the pin was in any other hole, you would not be able to trim the engines all the way in if/when needed.

To get an idea as to the most efficent throttle setting, that would be what is called in OMC's terms the "Cruising Range". Have the hood off, and have the engine in forward gear (leave it in gear but shut it down if it's running). Now, apply full throttle. Notice that the throttle butterflys are wide open and that the spark advance (timer base) is at its full spark advance setting. Now, while watching the throttle butterflys and the timer base, slowly start moving the throttle back towards the neutral position.

You'll notice that throttle butterflys start to close immediately, but the timer base (spark advance) is still at the full spark advance setting. You'll reach a point where the timer base will start to move towards retard...STOP! That is "Crusing Range"... The spark advance is a its fullest setting, but the throttle butterflys have closed considerably which does save fuel. Of course the boat has to stay on a plane to use this feature, and most do.

Either make a mental note or make a mark on the throttle control to remind you of the approximate throttle setting for that feature.

Note that this usually ends up to be somewhere around the 3/4 throttle setting, but it can not be obtained by going from idle to 3/4 throttle. You must go to full throttle first, then back off as needed to hit that cruising range.

Joe[img][/img]"

[ed]

now i can try to maximize the amount of fuel i have. hope to do some fishing next weekend! thank you joe.