Tweet
I have a late 80s model Yamaha 50 hp 2stroke. It’s always run pretty good but a couple months back it just went from fine to no acceleration. Basically it idles fairly good then when I advance the throttle it just Boggs and won’t go but 4 to 6 mph. I thought oh I’ve got my high speed jets clogged easy fix. Nope cleaned them up good all the little ports everything. Did the same thing under load. So I rebuilt the carbs. Drained and cleaned my fuel tank, replaced the fuel lines, installed a new fuel pump changed out the spark plugs pretty much a total tune up. So i read up about the coils and power pack. I tested my coils the primary terminals test fine but when I switch to the 20k on my ohm tester I get absolutely no reading on the secondary side?? I also tested them with the old style needle type and same thing the primary is fine but nothing on the secondary?? Could it be that all three coils are bad , and why go I get spark if they aren’t registering on the secondary side? Any information is appreciated please and thank you.
-
-
if you are getting spark, I do not see a problem with the coils.
but how are you testing the ohms?
my thoughts are to make sure you timing is advancing when you throttle up.
use a timing light to see that idle timing is in spec and then see if the timing advances to spec.
does this motor set up have a warning alarm and/or gauges to tell you when an overheat or low oil level is seen by the CDI
there is a chance the motor is overheating or thinks it is and is in RPM restriction mode
If oil injected, low oil or a failure of the system makes it think it has low oil level causing the same thing -
Not sure on the warning alarm . I recently took off my oil injection and premix now. But the problem existed before I did that. That is one thing I was going to look into possible limp mode or something. I don’t think it’s overheating it starts out directly off the launch maybe idling for three minutes before I advance the throttle. Pee is strong with a new impeller. I couldn’t find anything online except u tube on testing the coils with multi meters. I have digital and the needle type and did exactly what they did . The test on the secondary I get nothing on the digital and the needle barely moves on the other one. The primary terminals test normal ? Going to take them to a shop here and have them test them for me. I have access to a timing light so I’ll definitely check it out.Comment
-
I do see spark but under load I’m wondering if it’s intermittent or just no enough?? Gotta run some more tests . Thanks for your input.Comment
Comment