Yamaha 85hp 1993 no spark when applying power

[Bobby watt]

Hi guys and girls.
I just got a 3 cyilnder 2 stroke yamaha and it would not rev up but would idle. I have changed the stator fly wheel and pulser unit but same problem. I have cleaned the carbs and reeds.
I put a timing light on the coil leads (x3) and good indication of sparking on idle, when trying to rev engine there was no spark to no cylinders.
Is there a possable problem with the CDi unit.
The engine has been stored for many years and is new to very little used.

[99yam40]

You need to pick up a Yamaha service manual for your motor and follow it's guide line on testing ignition system. You will need a peak reading voltmeter or a DVA adapter with a regular voltmeter to get the readings and compare to the specs in the manual.
If the inputs to the CDI are all in spec and the out puts are not then you probably are looking at a problem with the CDI.

Some motors have 2 different charge coils ,one for low speed and one for high speed. maybe the high speed is bad on yours if it has two charge coils. Will have to check the manual and test

[jb123]

i would lean back towards carbs...
or neutral safety