1981 Mercury Black Max 225 ignition Stator Questions

[rblanc9000]

I have a problem with spark on cylinders 4-5-6. My question is how the stator is set up. It looks like there are 6 coils used for the alternator and 6 coils for ignition. 1-3-5 are on one switch block and 2-4-6 are on the other switch block. The wiring only has 2 wires from the stator to each switch block so I amassuming they use more than one coil at a time for ignition or they are all commonly connected in groups in the stator and only one coil is used for each firing. Resistance checks on the stator and the trigger coils check out fine. If you get it started and up on a plane it rocks and will get her up to 50 no problem but at low speeds it starts dropping cylinders and running rough. The Mercury Dealer has been very helpfull but wont work on my boat becuse it is overpowered. I just need to know if I have a good spark on at least one cylinder on each switch block does that meen the stator is good and the switch blocks are faulty or is it still possible the stator is bad.

 

[Laddies]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

You are right the stator and switchboxes effect odd or even number cyls. or a complete system heres a couple things to try discconnect the bond wire between the boxes on the kill circurt if a bais is bad in 1 box it will effect the other box thru that wire and if that don't help disconnect the 2 yellow wire from the rectifier and test run, a shorted rectifier will heat the stator and cause a random miss

 

[rblanc9000]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

So are you saying that if one coil in the ignition part of the stator assy. went bad then you would have one dead cylinder and the ignition only uses one coil for each cylinder or are they wired in a set of three and all 3 contribute to the stored voltage in the respective switchblock. I will try the suggestions you mentioned tonight when I get off work and see if there is any difference, Thanks for taking the time to educate a Auto tech with a broken boat.

 

[Laddies]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

No, the stator has 2 high speed windings (red and red/white) and 2 low speed windings (blue and blue/white for ign. each powers 1 switch box and each box fires 1 side of the V engine 1-3-5 or 2-4-6 plus the alternator windings, the trigger is 3 windings #1 winding effects 1-2, #2 winding effects 3-4 #3 windings effect 5-6 cyls it's function is to tell the switch box when to fire the coils would you like a the test for the system?

 

[rblanc9000]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

I get it, My diagram does not show anything inside the stator , just three pairs of wires coming out of it so I could not figure out for shure how they did it. I did the resistance checks with the stator wires disconnected and the result was right at the top of the spec. for the stator and tward the lower end for the trigger wires but all were in spec. If you have a more complete test that would be awesome. I really would like to pinpoint the failing parts and get her in the water before the seasons over. If you can email it to me at rblanc9000@aol.com that would be great, Roger.

 

[Laddies]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Roger, L can't figure out how to e-mail stuff so I PM it to you--Bob

 

[rblanc9000]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Thanks, I have a lot of things to check out now, Its nice to get a dynamic test to verify operation of the stator. Is it possible to check the output wires of the trigger with a lab scope. It seams it would be better to be able to view it and compare the signals to each other, obviously you would have no idea if the timing was correct but you should be able to verify a signal. Roger

 

[Laddies]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Roger, I don't belive that you can ck the voltage with a scope as it's AC, the other thing is I have never tried. I just use my Fluke meter and a DVA adapter to capture peak voltage

 

[rblanc9000]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Hey, Thanks for your time and patience. I wont be able to get out in the garage till saturday evening now and will do all the things you told me about. I hope you are far enough north to miss the bad weather , Im from the Chicago suburbs now living in Tacoma, Washington and they are getting spanked bad right now with massive floods and even some tornados were sighted over Chicago, They even shut down O'hare Airport today and they rarely ever shut that down even in snow and ice. Ill post any thing I find. They told me at the Mercury dealer that some of the Stators are almost $500 are the switch blocks expensive also or do you know? Thanks again, Roger

 

[quebec#1]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

I had my stator and one switch box replaced because at low speeds it starts dropping cylinders and running rough. It worked for two weekends and now its stating to act up again at low speeds once in a while at low speeds it starts dropping cylinders and running rough and smoking.
Can something else be wrong to make the startor and switch box to go bad ?

 

[Laddies]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Roger, Don't buy Mercury electrionic parts use CDI, merc has been plagued with failures, if CDI isn't available to you ck NAPA or other autoparts stores you deal with most sell Sierra or Primeline marine parts, might as well buy wholesale

 

[quebec#1]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Roger, Don't buy Mercury electrionic parts use CDI, merc has been plagued with failures, if CDI isn't available to you ck NAPA or other autoparts stores you deal with most sell Sierra or Primeline marine parts, might as well buy wholesale

Can you but a replacement startor and switch box at Napa ? What do you mean by using CDI ?

 

[rblanc9000]

Re: 1981 Mercury Black Max 225 ignition Stator Questions

Thanks for all the help everyone, poking around the internet the best price I have found for CDI parts so far was 119.01 for the switch block and 124.96 for the stator assy. both from boatfix.com. The highest was 160.00 for the blocks and 147.00 for the stator from another I place. At least I can replace all 3 for less than the high end guess from the Mercury Dealer.