charge coil good resistance, but bad voltage; is this possible? Yamaha 60TLRD 2005

astampfel

Petty Officer 2nd Class
Joined
Aug 2, 2010
Messages
100
My boat is limited to about 1500-2000 RPM when WOT. I cleaned the carbs, have new gas, good compression in each cylinder, but my spark is weak on cylinders 1 and 3. Cylinder 2 is strong for some reason. I changed the ignition coils to cylinder 2, and all work good. I changed the power pack ($500 mistake), retested the spark and basically same condition. The pulser coil has in spec resistance and voltage. The charge coil has in spec resistance but low voltage (about 14 volts at 1000 RPM when it should be around 120 volts per the Yamaha service manual). Should I replace the charge coil? What else could it be?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: charge coil good resistance, but bad voltage; is this possible? Yamaha 60TLRD 200

If you are reading charge coil with peak volt meter like manual says,
then voltage in is out of minimum spec
and the out put to coils from CDI will be low also
Did you take reading out of CDI also?

Need to take all readings with proper test equipment while troubleshooting just like manual calls for.
Charge coil reading low indicates bad charge coil is my thoughts
 

astampfel

Petty Officer 2nd Class
Joined
Aug 2, 2010
Messages
100
Re: charge coil good resistance, but bad voltage; is this possible? Yamaha 60TLRD 200

Thanks for the help. See my latest post for a full answer. Short story is that I made a DVA, it showed only 18 volts from my charge coil. So, I bought a coil and when I removed the flywheel to replace it, I saw a frayed wire coming from my old charge coil (rubbed on by the flywheel). I patched up the wire and rerouted it so it wouldn't rub and now my engine works fine!!!!!!!!! I am so upset that something that stupid was giving me such a headache!!!!!!!!!!!!
 
Top