1965 speedifour 75 HP Evinrude breaker adjustment

[akican]

My 1965 speedifour engine had only 80 PSI on compression test for all 4 cylinders. I don't know whether it is still good to make it run at this compression. The engine has been running before with good idle speed and WOT speed, but it is hard to restart after the engine is running for about 15 minutes. Today, I clean the carburetor, replace the O ring, gaskets, seat, needle and new float. Also I am replace the new breaker. According to the service manual, it said the breaker should be close at the first mark and second mark of the magneto flywheel and base plate. I do exactly to this, and get spark on four spark plugs. But the engine is not running at all. Took the spark plug out, and all of them are dry. I disassemble the carburetor again to see if there is any abnormal. Nothing is found. Putting it back and no start. I don't know whether the breaker gap adjustment is correct. Please advice.

 

[F_R]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

Will the spark jump a 1/4" gap? Jumping across the spark plug gap while laying against the head is not a spark test.

 

[Evinrude Boater]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

You can pour some mixed fuel (tablespoon each side) down the carbs to see if it will fire momentarily. If it does, then you have a fuel delivery problem with your reworked carburetors.

 

[Chris1956]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

80PSI on all cylinders is a bit low, however, when the motor is running the actual compression will be higher. If it is even, it is acceptable.

Does that motor have the distributor with two sets of points and a single condenser? If so, there are two timing marks (90 degrees apart) where one set of points should just open. You can adjust the points using a contunity meter and see that they open as they hit the timing mark, or set the gaps to max, and use a feeler gauge to set the gap for .020".

 

[F_R]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

Are you sure you got the belt timing correct?

 

[akican]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

I set up the timing belt according to service manual by aligning the crank shaft flywheel mark with the timing mark on the block. At the magneto end, I aligned the flywheel mark with the mark on the plate ( about the middle point of safety switch), then I installed the belt. Regarding the breaker's gap, I think i set it opened a little bit late because it just start opening when the wheel past the mark. Is it too late to ignite for that setup. Please advise.

 

[F_R]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

The points must open at the exact right time in relation to the magnets passing by the coil. That happens automatically if you have them gapped correctly. If they are off, it will weaken the spark.

 

[Evinrude Boater]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

What's the difference between the two methods of setting the points?

 

[F_R]

Re: 1965 speedifour 75 HP Evinrude breaker adjustment

Whether a person uses a feeler guage or uses the timing marks and a meter makes very little difference if done accuratly. The marks & meter method is easier and more precise because it doesn't depend on "feel".