A few Rude ?'s

ob15

Chief Petty Officer
Joined
Jan 4, 2004
Messages
514
First of all, I would like to thank everyone on this forum. I have learned quite a bit since signing up. Now I will get to my questions.<br /><br />To start off with, 1980 Evinrude 50 hp model #E50ELCSR.<br /><br />I have been researching the post to see if I can find the answers to the questions I have. I think I have found most of them but would like to ask for confirmation.<br /><br />1. I think I fried the rectifier when I first rigged my boat. There is a store nearby that has bins full of gauges for $10 each. They have a chart for setting the correct pole on the tach. The chart said to set the tach to 10 pole for this motor. When I first fired up the motor, the tach didn't seem to operate correctly so I changed the pole setting to see if that was the cause. I just didn't have the idle set correctly. From reading posts, it seems that the rectifier can be damaged by doing this. The tach seems to work fine at lower rpm but not at WOT. I canged props to see what would happen to rpm's but it didn't change. The tach reads 3500 at WOT even with a dramatic change (4") in prop pitch. I do have plenty of voltage to the battery while the motor is running. Here are the test results of the rectifier. Also, if the rectifier is bad, can that hurt the tach?<br /><br />MO=Millaohms<br />KO=Kiloohms<br /><br />Yellow/Gray & Ground 0 & 261KO<br />Yellow & Ground 0 & 136 KO<br />Yellow/Blue & Ground 0 & 136KO<br />Red & Yellow/Gray 0 & 0.62MO<br />Red & Yellow 0 & 0.66MO<br />Red & Yellow/Blue 0 & 0.68MO<br /><br />I am assuming the larger KO readings are infinite. It looks like the tests with the red lead shows failure (should be 0 & infinite).<br /><br />2. I have a Clymer manual for the motor and it reccomends a test speed of 4900 rpm when using a test wheel instead of a propeller. Is this the WOT rpm of the motor or just a recommended rpm for testing? I would think the WOT rpm would be 5000-5500.<br /><br />Thanks again & I really appreciate your responses.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: A few Rude ?'s

Dave....from your post, I'm gathering that you are trying to test the rectifier to see if it's any good? If so, see below....<br /><br />The rectifier has four leads...3 yellow and one red. To test, start with one yellow and red. Set the meter to ohms, mid scale, and connect the leads across the first yellow and the red. Then reverse the leads for the same wires.<br /><br />If no reading in one direction and full scale in the other, that yellow wire is ok.<br /><br />Read the other two yellow wires the same way. If any of the yellow wires fails the test, get a new rectifier.<br /><br />Test each yellow wire with the red.<br /><br />Keep us posted...and I hope this is what your looking for.
 
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