Low voltage on Stator blue wires for Mercury 115 HP 1991

[LoveMyBoatMTL]

Hi, I have installed a new stator (174-8778k1) on my Mercury 1989 115HP (2 stroke 4 cylinders – OC189xxx). Mechanically, the stator fits well with the size of the flywheel and all fixing screws. However, the voltage measured between Blue and Blue White wires is steady around 100V (DVA Peak Reading) instead of reaching an expected range of 180-400V according to the Mercury DVA Voltage and Resistance Chart (it failed for getting a spark). The circuit is not open and test measure returns 550Ohm well in the range specified by the manufacturer. All the flywheel magnets are originally glued and none are loose. I have no explanation for this failure. The Red to Red White and Yellow to Yellow circuits do not seem having this issue and it works as expected. Could it be the stator I bought does not fit my model or could there be a different issue?

For information, the engine with the old stator has significant trouble starting in cold weather. The voltage on my old stator fluctuated between 150 to 180 V (DVA), when the voltage is below 180 V it misfires. That's why I decided to change it.

 

[GA_Boater]

Welcome aboard.

What is the complete serial number. No way to search by serial number with xxx's.

 

[LoveMyBoatMTL]

Welcome aboard.

What is the complete serial number. No way to search by serial number with xxx's.

Hi, it is OC189035.

 

[Faztbullet]

Either switchbox internal rectifier has a problem and dropping voltage reading or that CDI junk is bad. Test the stator disconnected from switchbox and if readings are ok when cranking replace switchbox.

 

[LoveMyBoatMTL]

Either switchbox internal rectifier has a problem and dropping voltage reading or that CDI junk is bad. Test the stator disconnected from switchbox and if readings are ok when cranking replace switchbox.

Thanks for the reply, all the tests were done disconnected from the switch box and rectifier. I've already changed the rectifier as well.

 

[LoveMyBoatMTL]

Hi, I have posted a link of the DVA voltage tests with the old stator in the boat.

 

[Faztbullet]

Check the flywheel key and RPM of flywheel determines voltage output to switchbox. Slow crank = less voltage. I suspect you have a battery/starter problem and in cold weather it is magnified. I think your old stator is fine.

 

[LoveMyBoatMTL]

Check the flywheel key and RPM of flywheel determines voltage output to switchbox. Slow crank = less voltage. I suspect you have a battery/starter problem and in cold weather it is magnified. I think your old stator is fine.

Faztbullet, thank you for your input. I checked the flywheel key which is well secured and the reached RPMs are between 270-290 which is within those specified by the manufacturer (above 250). I performed all the tests using a Battery Charger and the "engine start" option on the charger. As mentioned in the original post, when I install the new stator the DVA is steadily around 100 V and doesn't fluctuate like the old one does on the video. I'm running out of ideas.