Mercury 2.4L Idling Issues

[fishscale28]

Top of the evening Gentlemen-

Here's my issue: I have a 1983 Mercury Black Max 200 hp outboard that took a bit of a swim a few weeks ago. It was only very partially submerged but nonetheless had a little bit more water than it should have (to just about the bottom carbs).

Immediately removed it from the water, cleaned it thoroughly, pumped some mineral spirits and fresh gas through and it started right up. Drained all the bowls on the bottom carb, ran some more fresh gas through and no issues at all. Since all this happened I have happily put about 15 hours on it and have run it through its paces and have had little to no issues except a crazy thing with the tach- twice and only temporarily it showed the engine as being about 1k over the actual rpms-still ran fine and sounded good but tach was way over.

Starting yesterday I was having some issues getting it started from cold (whereas before a few pumps of the primer bulb, a little choke and fired right up). Would take a little more time, little more throttle advance and would finally start with much much more smoke than usual. As throttle is advanced it seems to be ok but would sputter and die when put into neutral and especially into gear. If I jammed it from advanced to neutral to gear it would bog a little but would soon catch and be on my merry way. Even after running for 20 minutes or so would die as soon as put into N and would be very difficult to start without a good bit of throttle advance. Aside from that sounded good and ran well...

Thought it could be dirty carbs so took them off, dissassembled, thoroughly cleaned and reinstalled. Started right up and sounded good but was idling at about 1200. Let it run for about 10 minutes, untied and as soon as I put it into gear it died-again hard starting without advancing but got it going and decided to try and let it run a little bit under load. Put it in gear (very quickly) and still a little bog but caught and ran right up to 5500-sounded better than before-smooth, less shaking, ran great and sounded even better. Again-back to N would stall and be hard to start.

Changed plugs, changed fuel filter, checked for water in fuel and still the same. The plugs did look a little wet-could the stator not be giving it enough spark? Any other ideas and ways to try and trouble shoot?

Sorry for such a long post but wanted to be thorough. Thanks in advance for all your help!

[mygr8s10]

Check the output side of the "choke" or enrichener valve. Pull the hose off and squeeze the primer ball. there should be no fuel coming out. If there is fuel coming out it could be flooding the engine at idle. Just a thought and an easy one to find.

[fishscale28]

That could be a viable possibility-I will check that out tomorrow. If it is flooding the engine during idle what could be some possible solutions? Ive tried messing with the throttle levers (just the play and give that is already there) and pushing a little causes it to sputter. Releasing stops it from dying but idle is still high (about 1200).

Thanks!

[rdkvector]

I'm watching this, I'm having the same problem, going to change the stator tomorrow to eliminate that if it's not the problem. Subscribed!

[Capt.Insane-o]

try synching the carbs to be sure all the throttle plates are closed at idle.

[fishscale28]

I'll double check that in the am as well. I tried to get all that stuff ironed out before I put the airbox on but its worth another look. Would that help explain why it would bog down and die going into N and gear? Thanks!

[CKMATE225]

Before you go and change the stator you can do a simple test to determine if the low speed windings are bad, The symtums you are describing sound like a bad stator but, save yourself a couple of hundred bucks and a lot of agrivation by testing. You will need a multimeter and a manual. You do not have to remove the stator to test it, just a coupla wires off the switchboxes and test the resisteance( ohms) between the red and blue wires. Very easy.

[fishscale28]

Hi and thanks for the tip-I will check that out as soon as I have a chance (and this rain passes). Quick question though-as much as I know I need the manual I dont have one so would you mind posting the tolerances for the stator?

Thanks again!

[transomstand]

Was this thing dunked in salt?

Does it have an idle module?

[fishscale28]

Yes-it was salt water but none of the electronics got wet-just touched the bottom carb and barely that. As far as the idle module Im not sure-can you tell me a little bit of what it might look like or where it might be?

Thanks!

[transomstand]

Yes-it was salt water but none of the electronics got wet-just touched the bottom carb and barely that. As far as the idle module Im not sure-can you tell me a little bit of what it might look like or where it might be?

Thanks!

The idle/advance module will be a black plastic box, usually mounted at the rear of the powerhead, on top or the port side, with a couple wires going to the switchboxes.

Here's what I would do

1) Clean ALL engine grounds

2) Linc and sync

3) Check enricher operation

4) Disconnect idle stabilizer. If that fixes it, throw the stabilizer in the ocean.

Retest after each step, report any changes.

The fix should be in those 4 steps (If not, I'll refund my consulting fee in full:D)

[transomstand]

If you dump the module, you'll want to retime the engine, but we'll get to that later.

[Bruster]

Here is some pretty comprehensive information from CDI electronics. Everything you need to know about ignition systems and troubleshooting.

http://issuu.com/cdielectronics/docs/troubleshootingguide?mode=embed&layout=http%3A%2F%2Fskin.issuu.com%2Fv%2Fcolor%2Flayout.xml&backgroundColor=000000&showFlipBtn=true


.... Quick question though-as much as I know I need the manual I dont have one so would you mind posting the tolerances for the stator?

Thanks again!

[fishscale28]

Thanks so much for the link and info. As for the idle module I believe the gentleman who owned the boat prior to me removed it so shouldnt be an issue. I'll double check when I get home tho. Thanks again!

[fishscale28]

Evening everyone-

Not much of an update as the wind has been howling and haven't had a chance to spend much time out there but did go out and make sure all the linkages/butterflies were seated properly and to make sure the enrichener valve was functioning properly and to make sure there was no idle stabilizer. The linkages were slightly off, found a small gas leak in the fuel line, enrichener was working fine (seemed to be as it was still chocking properly) and didn't see anything resembling the description of the stabilzer.

Fixed the fuel line, fixed the linkages and gave it a go-finally got it to start up ok (was a little tougher than normal) and it sounded good with a bit of throttle advance and would almost idle ok but would quickly stutter and die. I did notice that advancing the throttle (or linkages) would save it no problem but would hesitate slightly and would soon catch, rev up perfectly but would shoot out some oily deposits from the exhaust. Almost sounds and looks like its not firing on all the cylinders. Does this help to offer any better ideas for troubleshooting?

Will get on checking the stator tomorrow and will keep you posted. Thanks again for all your help and look forward to getting this worked out!

[transomstand]

Time to check for spark.

[fishscale28]

And aside from having a spark tester an inductive timing light will work? Disconnect all the plug wires but the one being tested and turn the engine over while checking the light?

[transomstand]

Yes, it will. Ground any wires not connected.

[fishscale28]

Great thanks, I will let you know the verdict as soon as I can get to it. Thanks again!

[gmacrae]

4) Disconnect idle stabilizer. If that fixes it, throw the stabilizer in the ocean.

seconded... (apart from the littering thing maybe :D )

but when you remove the module, make sure you make up a small wire to create the bias circuit between the wht/blk terminals on the switchboxes... you probably know this... but i didnt :o

[fishscale28]

Ok gents had some time to go out and play around with things a bit and here is the story:

First got my timing light and started checking the starboard bank of plugs-no spark whatsover. Switched to port side and had some spark-seemingly strong and even in all three cylinders. As per the CDI info (thanks Bruster!!!) I was able to get to the stator leads, switch them around and then noticed that the problem switched sides. As per the info should mean that the stator is bad, correct?

So after all that I took my multimeter and tried to check the resistance. Wasn't able to get anything off the blue and blue/white but the read showed .14 (or 1400 depending on setting). Does any/all of that make sense? Could have easily been doing it wrong but think it was done pretty correctly (lead to engine ground and lead to wire to be tested).

If this all sounds like the stator let me know and if there is anything else I can go about checking I can do that and get on buying a stator as soon as I have confirmation. Thanks so much for all your help!

[transomstand]

You got those readings from the blue wires?

[fishscale28]

No sir from the red or red/white wire

[transomstand]

Seems a little odd about the low side. If it was open on both banks, the motor shouldn't run.

[fishscale28]

So does it sound like enough stuff leaning towards the stator being bad?

[rdkvector]

Test ohms between the blue and red, then the blue/white tracer to the red/white chaser, should be 5.8-6.2

[fishscale28]

Does it need to be running/turning over while I test?

[rdkvector]

No, but you have to pull those leads off the switchboxes.

[fishscale28]

Alrighty...As for the bank of plugs not working when the stator leads are switched-does that still mean the stator is bad or will this be the definitive test? And can I get by with just removing two of the leads from the switchbox and checking them or do they all need to be pulled? Just trying to find an easy test-boat is in the water and not the easiest to get to all the goodies. Thanks!

[rdkvector]

Pull them from both boxes and check both pairs, I just went through this.

[fishscale28]

Got it will do. And if they show different than the ohms you posted does that mark a bad stator?

[rdkvector]

You only need to pull the 2 wires from each box. Its tough when the boat is in the water.

[rdkvector]

Yes, you can call me if that helps, 941 544 8187, Rick.

[fishscale28]

Thanks Rick-I will head out when my flash light is charged and will give it a go. Will keep you posted. Thanks again!

[fishscale28]

Alright-just got back from checking it out-did as you said and removed all the stator leads from the boxes and got nothing from blue-red and blue/white-red/white. Was able to get the .14 (144, 1447, etc. depending on setting) when I checked both red and red tracer to ground. Any ideas?

[rdkvector]

Bad stator.

[fishscale28]

Thanks so much-will be ordering one now! Will the 16 Amp stator from CDI be a good one to get? (Part number 174-5456-16). Also-I was thinking about possibly updating all the wiring (as its all original, even the stator!)-might you have the appropriate CDI or OEM part number for that? Thanks again for all your help!

[rdkvector]

Do you have cdi now or is it Merc? What color is the flywheel?

[fishscale28]

The flywheel is a greenish-brownish color and its still the original stator, I believe.

[rdkvector]

I heard cdi stuff is garbage, but thats not my opinion, I really don't know the difference, I put a used Merc on mine, works great, I had cdi on it.
Any 16 amp stator will work. RL has a few for sale in the buy & sell forum.

[fishscale28]

Oh cool thanks for the heads up I will check on that shortly. Thanks again for all your help-owe you a beer!

[dwb212]

Low speed winding was open on my 2 liter 150, engine ran great besides it had a poor holeshot. looked around the internet and found the hype about cdi ignition parts being better than stock so i bought a new replacement cdi stator and it was no better than the bad merc stator.ordered a merc stator from european marine and the difference is night and day. lost a couple hundred dollars to a crappy cdi stator.

[fishscale28]

Evening Gents-

So got my new stator today (thanks to RL-great service and help all around) and have a question. I should have marked or left the original stator wires on the switchbox intact but left them undone after testing and need some help as to where they leads go (red, blue, red/white, blue/white). Basically if one were looking at the switchbox which wire would be first, second, etc. Also, there is a stray wire that was attached to one of the switchboxes that is red and white striped (not from the stator tho)-which terminal does that one go?

Thanks so much to everyone for all your help-cheers!

[gmacrae]

aren't your switchboxes labeled (red/wht, blu etc)?

[fishscale28]

They might be but to be honest I couldn't really see. Plus they're the original boxes from 83 ao maybe a little harder to tell?

[gmacrae]

I've only seen a few original merc switchboxes but they've all been labeled, go look closer :)

[rdkvector]

They will be labeled, but the wires with the white tracer go to the outside switchbox.

[fishscale28]

Thank everyone for all your suggestions, recommendations, advice and assistance. As of the AM got the beast up and running again with nice, even spark on all 6 cylinders and will be back on the water in a matter of moments. Thanks again!

[fishscale28]

Alright I gents on second thought I guess there are some more issues now. Got the stator on and wired up correctly and it idles ok but now I cant get it to go over 1600 RPMs in gear. It revs fine when I push the levers on the carbs but while underway it dogs right around 15-1600. Any ideas? Only thing that has changed has been the stator...

[gmacrae]

can you use the timing light to check if you're losing spark somewhere when the motor falls flat? I doubt it's got anything to do with this but have you ever rebuilt the fuel pump? (little square one on the block). Its a very cheap kit from merc and only takes about 20 minutes to do - just good to know it's done.

[gmacrae]

Also, is the stator brand new? Kinda sounds a bit like the high speed winding might be shot? Test the new stator perhaps, I think someone a couple pages back mentioned they got a bad CDI stator. If the high speed winding is toast (for half the motor - one switchbox) it could explain why it will free-rev ok (on 3 cyls) but can't rev under load... i dunno, just thinking out loud here

[fishscale28]

I was kind of thinking the high speed windings might be bad too-Ill have to go and check those again. Pretty sure it is a new stator will have to double check with the gentleman I purchased it from. I checked and there is good spark on all the cylinders while being throttled at the dock-Ill have to find a buddy to go out on the water with me to check while underway

[fishscale28]

Just checked the leads and am getting 74.1 (or .074 depending on how you look at it) from the Red and Red/White (to ground) and nothing at all from either of the blue leads. High speed windings bad?

[gmacrae]

The manual I have says test:

red-blu: 5.4-6.2k ohm
red/wht-blu/wht: 5.4-6.2k ohm
^meter should be set on the *k ohm scale ^

red-gnd: 125-175ohm
red/wht-gnd: 125-175ohm
^meter should be set on *hundred ohm^

EDIT: "Stators with PN 398-5454A34 stamped should indicate 65 to 75 ohms" - that is on the red to gnd and the red/wht to gnd.

Test with all wires disconnected

These are specs for a merc stator of course, if its CDI it will likely test differently. Still, you should have a resistance reading if testing the wires as above. If no continuity at all (so the meter doesn't change when you put it on the wires), the winding must be broken/open. Are you testing blu-red or blu-gnd?

[fishscale28]

Hi and thanks for that info. Im testing all the leads to ground. There is no change/reading at all when testing any of the blues and only get something when testing the red and red/white to ground.

[rdkvector]

It sounds like there is no advance of the timing. Did you check linkage?

[rdkvector]

Another thought, is the stator compatible with the flywheel?

[fishscale28]

As for the stator-that is a good question I am going to have to check with RL-it sounded like all was good to go and this was the right stator for it but still could be an issue. As for the linkages I checked them and all seemed to be working out. I will check it again just to make sure...

[gmacrae]

another thing, when trying to diagnose the problems I was having with mine, another forum member helped me out with this he found this printed in a manual:

"Stators with PN 398-5454A34 stamped should indicate 65 to 75 ohms" - that is on the red to gnd and the red/wht to gnd. If you have that stator (like I do) it would explain your low readings to gnd.

[fishscale28]

That would make sense and those numbers do look familiar. So if that is the case what exactly does that mean? Would there still be a reason why there is no reading from the blue and blue/white wires?

[gmacrae]

back in my thread (Was just reading over it again), I wasn't getting any readings from testing the blu-red or blu/wht-red/wht leads either. I think it was just because I didn't know what scale to set the multimeter to. Try taking readings between those leads again and make sure the meter is set in the thousands of ohms scale (meter will probably say 2k ohm or 2000). So on the meter pictured, you'd test the red-gnd on the 200 scale, and test the red/blue on the 2000 scale.

Hope that helps, those scale settings used to confuse the sh*t outta me too

http://www.dansdata.com/images/caselight/multimeter440.jpg

Hopefully if i've put you wrong anywhere someone sharper than me will pick it up and point it out - i'm still very much learning these things myself

[fishscale28]

Alrighty thanks for the tip that does clear it up a bit. I will double check in a little while and post back

[fishscale28]

Alright here's the latest=I think rdkvector was onto something with the timing not advancing. I popped the flywheel off again just to double check everything on the stator and noticed the lever going underneath the flywheel/stator (guessing it has to do with the timing) was catching so I cleared that up and now it moves freely as it should. Will try it tomorrow as to not wake the neighbors...

As for checking out the stator I was finally able to get a reading by fooling around with the setting on the DMM-but only at the 20k setting and I was getting 4.21 between the blue and red. Dont know if my meter is just way out of whack but it seems fine on everything else I've checked out. I checked all the spark earlier with the timing light and all looked well so Im thinking the timing lever was the issue. I am going to go ahead and replace the grounds on the switchbox and the bias wire as it is a little soft and mushy. Better safe than sorry I guess. Thanks again everyone and I will keep you posted tomorrow

[fishscale28]

That was it-the trigger wasnt able to move for the timing to advance so all is well. Thanks again for everyone's help!

[gmacrae]

awesome, glad you sorted it, nice diagnosing rdkvector!

also check your WOT timing advance if you haven't already, changing ignition parts could've moved it slightly, better safe than (very) sorry