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80's 45hp Mercury possible stator problems?

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Noelie84

Member
Hello!
I just purchased (as in, 4 hours ago) a 1966 Corson 17' runabout with an 80's-vintage Mercury 45hp 4 cylinder 2-stroke OB (OB205350 I think; it's pretty faded so it might be a OB205750). The motor runs fine above 2000rpm (ish) but won't idle. The previous owner cleaned and rebuilt the carbs thinking it was a fuel issue, then replaced plugs, wires, and the switchbox. When that didn't fix it he threw a wrench through the drywall in his garage (he showed me the hole) and put the boat on Craigslist for $350 where yours truly saw it and picked it up.
Now, the PO says that the local Marina said it sounded like a bad Stator and offered to sell him a new one for $450. I managed to find an aftermarket replacement online for $150, but this is my first outboard engine and before I drop 1/2 the price of my new boat on a stator I thought I'd ask some folks with more experience.
I did a couple of tests this afternoon and it appears that I have high fire but not low fire. I did an ohm test with my multimeter but got no results from either the blue/white-to-blue or the red/white-to-white test (maybe I did it wrong? Lifelong tinkerer but like I said this is my first OB. I don't see any signs of damage to the stator itself; no discoloration or melted-looking spots, but I know that appearance doesn't always mean much. Boat has a black stator, for what it's worth, part #398-5454A26 and I think it's dated 09/97.

Has anybody else run into this problem before? And if so, how did you fix it? Does this sound like a Stator issue?


Edit- I almost forgot: PO says that they can take the boat out to the lake and it'll start on 2 cylinders and then once it's warmed up he can shut it off and the other 2 will 'usually' kick in when he restarts it. No idea what that might mean.
 
Update on this issue:
I retested the stator with my multimeter on the correct settings (der) and I did get readings from it. The Blue and Blue/White wires tested at 5900, and the Red to Red/White tested at 70. No continuity between either the red or blue lead and the ground wire.
Also, I put everything back together and now it won't start at all. I've checked and rechecked everything that I took apart and it's all back together correctly (stator back in the correct location and bolted in correctly, flywheel/ring gear in the correct timing location, all wires hooked back up to where they're supposed to be.
I'm stumped.
Does anybody have any suggestions on what the problem might be? I'm trying to avoid a trip to the local marina (because $$$), but I'm also not interested in this boat being a lawn ornament, lol. I'm pretty mechanically inclined, so if somebody can advise me on what to do I can probably manage it. But where this is my first outboard engine it's all kind of a mystery. Right now I look at it and all I see is a malevolent black lump of spite and stubbornness.
 
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You got to have what you call low fire for it to start as high speed side don't switch in switchbox till about 1800-2000rpm. Do you have fire on all 4 cylinders at cranking/idle??? What are start wires Jeff?????
 
Aha...
That explains why the trigger rotates ahead at a certain point when you open up the throttle, then? Just like secondaries on a 4 bbl carb, but as part of an electrical system?
That'd certainly explain why I can't get it running, then. I hooked up the timing light to all 4 plug wires and had the GF crank it over, and I've got no spark on any of them at cranking speed. I ran through the wiring with a circuit tester after work last night and the off/run switch is functioning properly, as are the on/off settings on the key (the black and yellow wire at the switchbox only shows current when the key or the switch are set to 'off'), the tilt switch is working correctly, and all of the coils are properly grounded. I also checked continuity between all of the wiring between the key and the motor with my multimeter to make sure I wasn't missing a blown fuse or broken wire somewhere along the line.

So all of this seems to be adding up to a bad stator? Sorry if this is an obvious question; I understand the basics from years of tinkering with old cars, but I'm not familiar enough with outboards to make a confident diagnosis on my own.
 
faztbullet said:
If you have no spark when cranking remove the blk/yel wire rom switchbox and retest.
Click to expand...

Already tried that. Also removed the wire from the tilt switch and tested. Still no spark. Then I confirmed that all three switches (ignition cutoff, ignition key, and tilt) were working correctly with the circuit tester. And I tested all of the wires between the ignition switch and the motor for continuity with the multimeter to make absolutely sure. None of the coil packs is kicking any spark to the plugs. Or if they are, it's not even strong enough to flash the bulb on my test light. Battery is almost new, fully charged, and putting out the correct voltage, the cables are in good shape and the connections are clean. No blown fuses that I can find. All of the wires in the engine itself are in good shape and have continuity. She spins like crazy but no spark.
 
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faztbullet said:
Throw the test light away and get a meter and DA and test outputs from trigger and stator.....
Click to expand...

By meter I'm assuming you mean a multimeter. I already checked the Stator, results are in my second post on this thread. The Blue and Blue/White wires tested at 5900, and the Red to Red/White tested at 70. No continuity between either the red or blue lead and the ground wire. What sort of readings should I get from the Trigger, and what wires should I be checking?

As for the DA, not sure what that would be.
 
Managed to rule out the Stator, coils, wires, switchbox, and every piece of wiring between the engine and the throttle control with my multimeter and old-fashioned circuit tester. Finally I bit the bullet and popped the piece that the flywheel bolts to (wasn't THAT a pain to get loose; I don't think it'd ever been off) so I could do a visual inspection of the trigger. Turns out that the insulation on one of the wires had chafed/worn through in a tiny (like, 1mm spot), probably from years of moving back and forth with the throttle control. So even though it ohm'd out ok according to the specs I found online, I think that when the engine was actually running it was grounding/shorting out on the block (I know that it'll affect a regular engine when that sort of thing happens, so I'm assuming it holds true with an outboard as well).

I got the new trigger in the mail yesterday and presto-chango she now runs perfectly.

Thanks everybody for all the help chasing this.
 
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