maximum revs for shifting into gear on 1970 40hp Evinrude

[Monte NZ]

Help please,
I have hunted high and low in all my manuals and looked on Google, but cannot find the maximum idle speed for shifting into gear.
I suspect it would be about 650 rpms.
Running the motor using a flushing unit she will idle at 500 revs ( using a 1960s Airguide Rev counter.)
When I run it in the lake the motor tends to easily stall and I suspect it is the back pressure of the water on the exhaust outlet.

Thanks in advance.
Monte NZ

[garry-in-michigan]

In the original patent application (1936) There was a three piece drive shaft consisting of a long tube with a spring coiled inside connected to the crankshaft. Inside the spring was the driveshaft plugged into the pinion gear. The bottom of that spring was pinned to the inside shaft. The coiling of the spring around the inner shaft was supposed to absorb the shock of shifting and extend the life of the mechanism. The clearances allowed this to happen in about one or two revolutions. 1000 hour testing in salt water seemed to prove the rubber clutch on the Lightfour prop was a good shock absorber, as the spring was rusted up tight. So Johnson put it on there QD model in 1949 with a one piece drive shaft. It was found that the greatest damage was done to tho dog clutch by trying the “ease it” into gear. There is about 30 degrees of “free space” for the clutch to move into engagement. This gives you milliseconds to move the shift lever. They origanally said to adjust the idea for the smoothest opperation. you will find as you turn the idea needle valve in (leaning the mixture) the engine will increase until the outboard sneezes and stops. Know also shifting into neutral speeds up the motor and will lean out the mix causing a “sneeze” . Mixture setting and idle RPM vary with the engine. It seems like you have a good handle on what the speed should be. On later models where an individual service manual is available, an idle RPM recommendation is given in the carburetor section, For example, the figure given for the 1968 85 horse Evinrude is 700 to 750 RPM. It has a very dependable electric shift. . . [/color]

• This reply was modified 5 years, 2 months ago by garry-in-michigan.

[billw]

I suspect it is time for an evaluation of the engine. The big ol’ cans of a 1970 40 make it so they are unlikely to stall, even on one cylinder. Do a compression check, tune up and try again…May be as simple as a carb adjustment. But 650-700 RPM sounds like a reasonable number to shoot for. I’m not sure your question has an answer that is in print; but if anybody knows, it will be these guys.

Long live American manufacturing!

[frankr]

You are good. Especially if it will come way down to 500 RPM. That’s better than expected. Straight out of the Evinrude service manual, set idle speed to 650 RPM In Gear. More important, always shift at as slow a speed possible without stalling, and shift with a quick, snappy movement. Never “Ease” it into gear.

[dave-bernard]

I would think set it at 650-700 IN GEAR.

[garry-in-michigan]

I spent two hours last night typing my answer, but when I hit “enter” it would take me to the top of the page and erase my post. Hitting the “back” command would show what I had written. So I copied it and pasted in when it was erased. After a dozen trysI gave up and went to bed. I checked this morning and was disappointed to see it was truly gone. I have also had problems with the color of the letters sticking, Has anyone else had this problem?

[billw]

So why is his engine stalling? Is he saying he is TRYING to shift at 500?

Long live American manufacturing!

[fleetwin]

Perhaps you are confusing the issue trying to evaluate idle speed and shifting while running on a flushette. Most everything changes when running and shifting the engine on a boat in the water. I guess what I’m driving at is if you are trying to set idle speed and needle adjustments while running on a flushette, the engine will probably stall when you put it on the water….
All these adjustments should be made only when the engine is on the boat, in the water, and idling in gear with the correct propeller installed…

[Monte NZ]

Thanks everyone for you input………much appreciated!
Thanks too Frank for confirming from Evinrude literature that 650rpms is the figure IN GEAR.
I will be taking part in a Classic Wooden Boat Parade at the weekend and there will be a lot of boats mllling round slowly at close quarters so it will be good to get the idling sorted.
FOOTNOTE.
I took a run out on the lake this afternoon and did some adjustments which made a big improvement. May I add that the motor starts and runs beautifully and is always been kept in top condition.

Thanks again everyone
Monte NZ

[Monte NZ]

Hi All
Just a brief note to let you know the motor ran like a watch at the parade and didn’t stall once!

Thanks again for your help.
Monte NZ

[Author]

Posts