DVA reading all over the place

[chris0061]

Working on a 1972 Evinrude 50 hp lark. Have posted several posts now have a new problem. I developed a miss first at wot then at half then down to just above idle. Started testing and noticed one new coil blew. tested the power pack and from the cdi website I determined the pack was bad. Got a new one and replaced the coil and started it and seems to run ok but when I do the dva test on the pack the reading is all over the place all the way up to 1800 v at times. Brown stator wire is the same as is the coil leads. Anyone have any ideas what this could be. I unhook the brwon stator wire and get 237v on dva wich is in spec. Don't really know were to look next. CDI is taking the new pack back to test it and repair or replace.

 

[durban]

Re: DVA reading all over the place

have you tested the sensors one could be playing up

 

[boobie]

Re: DVA reading all over the place

Check it again when you get the new pack back.

 

[seahorse5]

Re: DVA reading all over the place

Inexpensive digital meters often are not shielded good enough and will pickup RFI from testing components. Insufficient dampening is another thing that could be causing the numbers to jump around.

Often the only fix is to try other meters to see if you get a steadier reading - Fluke brand is one of the better ones that pros use.

Like "the Boob" said, see what the replacement pack does.

 

[chris0061]

Re: DVA reading all over the place

while waiting on the new pack I picked up another motor and put all the parts on mine and got the same readings. The thing sounds great and runs great. I had blown a coil but I think maybe it was cause of a bad boot and it was arking out on the block. If it was actually putting out 1800 volts on and off would that blow a coil after time or would it blow it right away. My job has flukes I'll try to borrow one and try it.

 

[boobie]

Re: DVA reading all over the place

Agree+ 1 with seahorse5...........

 

[chris0061]

Re: DVA reading all over the place

got a call from cdi today and they said the pack was fine. Couldn't get the fluke yet. I don't know what is going on but I guess I'll just run it and assume the meeter is not reading right.

 

[chris0061]

Re: DVA reading all over the place

to update. I had forgot to mention that I had picked up another throttle control and the shift switch only had 3 terminal were the original had 5. to make a long story short, I was welding today and thinking that when I first got the trigger and got the motor running I took it out and it ran great till it laid down on me. Tonight I came home and put the original controls on it and bam, the erratic reading was gone, it sounded better at idle and when you cracked the throttle, less draw when shifted into gear. I'll take it out tomorrow and see how it does but bottom line is that the entire problem was in the throttle control weather it was the ignition switch or the shift switch I don't know but had to be one of them.