84 Merc 150 stator question

Doug57

Seaman
Joined
Jan 6, 2010
Messages
58
I had to put a stator on my motor a few weeks back. I replaced it with an after market stator. motor has been running great. Even fixed a loading problem i had at idle. I've been to the lake 4 or 5 times. The last trip was a three day trip and the boat was used allot. Then started running really rough and weak. I checked compression and all are 127 to 132 PSI. Had fire on 1,3 & 5 none on 2,4 & 6. I swapped the blue and red wires from the top switch box to the bottom box and moved the blue/whith and red/white wires to the top box. Fire moved from 1,3,5 to 2,4,6. Also I didn't mention the tach quit working, So I'm reasonably sure the new stator is gone.

My question is, is there something that would cause that stator to go bad so quick or is it just one of those (if your gonna play you gotta pay) things?
 

sschefer

Rear Admiral
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Nov 13, 2008
Messages
4,530
Re: 84 Merc 150 stator question

I'll hazard a guess that its a 16amp stator and the two yellow wires connect to a small voltage rectifier just to the left of the starter solenoid.

If that is the case, remove the gray tach wire from the terminal and check for spark. If spark returns then replace the tach. If the condition still persists then remove both yellow wires from the rectifier and check spark again. If spark returns, replace the rectifier. If spark doesn't change then your suspicions are probably correct.

Was the OEM stator a CDI? If so, it's a good one with a good warranty.
 

j_martin

Admiral
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Sep 22, 2006
Messages
7,474
Re: 84 Merc 150 stator question

Did the new stator look pretty much like the old one? I ask because it's possible to swap out a 16 amp system to a 40 amp, and if you put a 16 amp stator back in with the 40 flywheel, it'll smoke in short order, but run like a scalded dog till it does.
 

Doug57

Seaman
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Jan 6, 2010
Messages
58
Re: 84 Merc 150 stator question

I'm nor sure on the OEM stator. The new one is a CDI Part# 174-5456. The old stator has a coating that covers the entire stator where the new one doesn't. The part# on the old stator is 398-5454A6. Engine serial #6569594.

I disconnected the tach wire, no change then disconnected both yellow wires from rectifier, no change.
 

j_martin

Admiral
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Sep 22, 2006
Messages
7,474
Re: 84 Merc 150 stator question

Those are 9 amp stators. Stock is 16 amp. Stock stator is 398-5454a32, CDI is 174-5456-16.

They all look the same, but they're different.

Post a picture of the flywheel.
 

j_martin

Admiral
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Sep 22, 2006
Messages
7,474
Re: 84 Merc 150 stator question

Stock 16 amp flywheel. Maybe same for 9 amp, I'm not sure. Sschefer might know.

Good news, there's about a gazillion 16 amp stators on the used market, any one of them will work.

174-5456-16 18-5860 18-5871 9-25504 9-25508 398-5454A11 398-5454A15 398-5454A16 398-5454A30 398-5454A31 398-5454A32 398-5454A34 398-5454A35 398-5454A36 398-5454A55 398-5454A61 398-5454A64
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 84 Merc 150 stator question

That a 9 amp stator(5456)...and flywheels are interchangable after 1987.
 

Doug57

Seaman
Joined
Jan 6, 2010
Messages
58
Re: 84 Merc 150 stator question

Thanks John

So the stator the sold me a few weeks back (CDI # 174-5456) is a 9 amp? Would that cause it to go bad so quickly?
 

MFisher

Cadet
Joined
May 29, 2010
Messages
27
Re: 84 Merc 150 stator question

Sorry for butting in on your thread but I believe I just ran into the same thing with my 85 150xr2. I have no fire on the cylinders 1 3 5, now I swapped the the red and blue wires from the upper and lower switch boxes but the same side 1 3 5 still not firing. I had spark just the other day but the boat was running a little rough. Now it barely wants to run what or how shoulld i check to see if it's the stator or could it be something else.
 
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