Need help--older Mariner 40EL rough idle with bad shaking in gear

[RaisedByWolves]

Advice just like NC Cat?

You mean that my whole issue is because I'm using a trash can? That I clearly stated it was doing the exact same thing on the water BEFORE the trash can ever came into the picture? I appreciate the thought, but I really don't see the connection--it came across as someone that doesn't have an answer but has to say something anyway. Sorry I responded in kind.

Advice like the left field stuff you've offered in some of your posts in the past?

I'll pass, friend. You're welcome to move along.

The fact that you dont see the connection is how we got here in the first place.

In short, without the prop in clean water moving the boat you will never set the idle properly.

Maybe read a service manual, its in there.

Knowing this, anyone who has any common sense (Which isint all that common) would spend 5-10 minutes at least trying to adjust the idle on the water like the service manuals state before doing anything else. Its free and simple once you see the connection.

Finally, as to the part in red, please.....please.. point out all of my "Left field Stuff" in "some of my posts" in the past.

Im sure it will be a hoot.

 

[CedarRiverScooter]

Not to confound the issue, but long ago I had a motor with exhaust leak under the shroud & it would idle poorly.

 

[RaisedByWolves]

Not to confound the issue, but long ago I had a motor with exhaust leak under the shroud & it would idle poorly.

Was this while it was in a barrel or on the lake? :lol:

Makes perfect sense though as its rebreathing its own exhaust.

Once the revs went up it was probably pulling in enough fresh air to run properly.

But what the hell do I know, I'm full of bad advise.

 

[CedarRiverScooter]

On the river. It was a 125 'rude, was strong motor!

I paid to have the gasket replaced. That helped but that motor never idled smoothly.

 

[BrounHownd]

As an update and to provide some closure....

Pulled the carbs apart again, cleaned them again, focused on the idle jets and passages again.

Drove the hour to the nearest quiet ramp with a dock so I wasn't using my trash can. Ran the boat to warm it up. Tied it to the dock and went through the link, sync, and idle adjustment process again. Better, not fixed. Still sounds like a miss/stumble at idle.

Drove the hour back home. Replaced the CDI unit that tested bad (according to the service manual, which I keep getting told to read by the same people that seem to think it's not useful). Put it in the test tank. Idles like a 40-year-old motor could be expected to after some minor adjusting.

I'll be sure to report back after I get a chance to put it back in the water, but I think the test tank got me close this time.

I appreciate the useful feedback I've received and will hang around here reading and learning until the next issue crops up.

 

[RaisedByWolves]

As an update and to provide some closure....

Pulled the carbs apart again, cleaned them again, focused on the idle jets and passages again.

Drove the hour to the nearest quiet ramp with a dock so I wasn't using my trash can. Ran the boat to warm it up. Tied it to the dock and went through the link, sync, and idle adjustment process again. Better, not fixed. Still sounds like a miss/stumble at idle.

Drove the hour back home. Replaced the CDI unit that tested bad (according to the service manual, which I keep getting told to read by the same people that seem to think it's not useful). Put it in the test tank. Idles like a 40-year-old motor could be expected to after some minor adjusting.

I'll be sure to report back after I get a chance to put it back in the water, but I think the test tank got me close this time.

I appreciate the useful feedback I've received and will hang around here reading and learning until the next issue crops up.

Curious as to why you chose to replace the suspect CDI after you drove an hour to the lake and back.

Something is not adding up here.

Who was it that told you the service manual was not useful?

I dont remember that.

 

[nytebyte]

You're test tank is fine for initial tunning but you might want to have a fan blowing if it looks like its is getting a lot of exhaust fumes being sucked in as that will afect the idle. I have tuned many motors in a test tank and a few may need a final adjustment on the lake but you will be close in your tank.

 

[BrounHownd]

As an update and to provide some closure....

Pulled the carbs apart again, cleaned them again, focused on the idle jets and passages again.

Drove the hour to the nearest quiet ramp with a dock so I wasn't using my trash can. Ran the boat to warm it up. Tied it to the dock and went through the link, sync, and idle adjustment process again. Better, not fixed. Still sounds like a miss/stumble at idle.

Drove the hour back home. Replaced the CDI unit that tested bad (according to the service manual, which I keep getting told to read by the same people that seem to think it's not useful). Put it in the test tank. Idles like a 40-year-old motor could be expected to after some minor adjusting.

I'll be sure to report back after I get a chance to put it back in the water, but I think the test tank got me close this time.

I appreciate the useful feedback I've received and will hang around here reading and learning until the next issue crops up.

Curious as to why you chose to replace the suspect CDI after you drove an hour to the lake and back.

Something is not adding up here.

Who was it that told you the service manual was not useful?

I dont remember that.

Because I hadn't ordered it yet, Columbo. But if it's more fun from your perspective---you busted me.

As to the manual, you dismissed it as valid when it pointed me to the coil and CDI, but wanted me to follow it to the letter when you THOUGHT it said to go to the lake (it doesn't, and you can check the source in the first reply).

But you've been entertaining if nothing else.

Was on the lake this morning. Ran great.

 

[turbotodd]

I am not 100% familiar with that motor. Is the CDI a Yamaha or Mercury part?

Generally speaking, on yamaha stuff, the cdi's don't die. Or more specifically if there is a problem with them they just won't make a spark, hence the engine will never run. I have never (ever) seen one that would intermittently spark. Not that it doesn't happen, I just have never seen or heard of it, with yamaha.

Mercury, on the other hand, completely different story! Their electronics are, IMO, subpar. Another topic for another day...

if there were an erratic spark issue, or intermittent spark issue, a timing light would (usually) identify it pretty easily.

on any 2 stroke outboard the spark timing and carburetor have to be spot on. They don't "like" to be "off" much at all except for one or two degrees more advance up top (top speed) on SOME outboards. Most of the time the specified is perfect.

Again I don't know your outboard. On some of the older Yamaha C40's (twin carb twin cyl) it wasn't uncommon for me to have them show up at the shop with similar complaints from owners; who may or may not have had them "repaired" at another shop. Some things I saw. Jets cleaned with a drill bit or torch tip cleaner (makes the jet bigger). Carb passages cleaned with same manner (increases orifice sizes). Forgetting that there is a teeny tiny jet in the top (F25's specifically) and blowing the carb body out, the jet is lost; and it idles like poo. And the most common, forgetting to sync the carburetors and spark advance linkages after removal/reinstallation. The carbs themselves need synchronized, then sync the spark advance linkage to the carb(s). Carb sync is obviously not applicable on single carb motors but spark timing sync IS. Very common mistake. Not saying this is your issue, simply mentioning it.

Sometimes cleaning a carburetor becomes routine, you kinda just do it automatically and tend to forget the little details that normally aren't addressed. Like pulling the bowl, removing jets, cleaning, reassembling--and forgetting the atomizer tube, gasket, then the air bleed holes in the main body, and on some motors the prime start passageways and accelerator pump (which your ole 40 won't have). Even I have to remind myself that every situation is completely different, you MUST be thorough, or prepare to do it multiple times until it's finally fixed.

by the way when checking the timing, it may be wise (particularly on older motors) to verify that the pointer is actually correct. In other words, turn the engine to true TDC, verify TDC a second time, and make sure the pointer shows zero. I've seen a number of them off-some quite a bit (up to 10-12 degrees). Oh and I seem to remember a merc that had a sheared flywheel key, it seemed to run fine except low speed (retarded spark timing).

oil fuel mix. Some motors are designed to run 100:1 and guys will NOT do it, and then they gripe about idle quality. Well you're running twice the amount of oil through it so it's going to idle a little differently. Similarly, when fuel sits for a long time, it evaporates-but leaves behind the oil. So you mixed up 5 gal at 50:1 and in a few months you have 3 gal at 30:1, and the gas-is junk at that point. More 2 stroke outboard engines have experienced problems related to fuel and/or oil than any other problem combined. Again, not saying you have this issue-just pointing it out for those who might be web searching for idling issues.

There's been a time or two where I could not get them to idle properly, period. Normally it was due to a mechanical problem internal to the engine, whether it be water ingestion through a leaking gasket, low compression, leaking crankshaft seal, air leak between the block halves, air leak at the reed valve block, broken/damaged reed assembly, whatever. Those were pretty rare but again I did mostly yamaha stuff for the last 30 years, had about 4 years prior to that with Mercury. Mercury will keep techs busy. Yamaha? About like a maytag repairman. Sit on your thumbs waiting for the next carburetor cleaning to show up.

 

[RaisedByWolves]

As an update and to provide some closure....

Pulled the carbs apart again, cleaned them again, focused on the idle jets and passages again.

Drove the hour to the nearest quiet ramp with a dock so I wasn't using my trash can. Ran the boat to warm it up. Tied it to the dock and went through the link, sync, and idle adjustment process again. Better, not fixed. Still sounds like a miss/stumble at idle.

Drove the hour back home. Replaced the CDI unit that tested bad (according to the service manual, which I keep getting told to read by the same people that seem to think it's not useful). Put it in the test tank. Idles like a 40-year-old motor could be expected to after some minor adjusting.

I'll be sure to report back after I get a chance to put it back in the water, but I think the test tank got me close this time.

I appreciate the useful feedback I've received and will hang around here reading and learning until the next issue crops up.

Curious as to why you chose to replace the suspect CDI after you drove an hour to the lake and back.

Something is not adding up here.

Who was it that told you the service manual was not useful?

I dont remember that.

Because I hadn't ordered it yet, Columbo. But if it's more fun from your perspective---you busted me.

As to the manual, you dismissed it as valid when it pointed me to the coil and CDI, but wanted me to follow it to the letter when you THOUGHT it said to go to the lake (it doesn't, and you can check the source in the first reply).

But you've been entertaining if nothing else.

Was on the lake this morning. Ran great.

You sir are a liar and making this up out of whole cloth to hide how bad you have been screwing this whole episode up.

You're fooling no one but yourself.

 

[RaisedByWolves]

I am not 100% familiar with that motor. Is the CDI a Yamaha or Mercury part?

Generally speaking, on yamaha stuff, the cdi's don't die. Or more specifically if there is a problem with them they just won't make a spark, hence the engine will never run. I have never (ever) seen one that would intermittently spark. Not that it doesn't happen, I just have never seen or heard of it, with yamaha.

Im going to give you a clue, hes full of doo doo and never replaced the CDI.

In way over his head with the knowledge base here and continues to flounder his way into further embarrassment.

In 5 days he cleaned both carbs, spent a day going to the lake and tested this work, ordered and recieved a new CDI and installed and tested this too. :lol:

On top of that, he synched twin carbs with no knowledge of what hes doing IN A BARREL NO LESS and wants us to believe its now running great due to his jet snapping skill set.

OP is now a certified YammyHammy tech, Believe it!

Or he'll put words in your mouth. :---)

 

[old_fart]

I have a 55 gallon plastic drum that I've cut down to about 40 gallons. I test, tune, and repair my outboards in that and it has always worked fine for me. Maybe there's something different about testing it on the water but it's sure inconvenient when all my tools and my shop are on dry land.

Trailering to the nearest ramp, looking for a place to dock out of everyone's way, working without all of my tools available, and trying to make repairs hanging off the back of the boat seems like the hard way to do it.

Completely agree.

The one downside to tuning at home, though, is the beer cans are still in the yard the next morning after you throw them overboard.

Hey....
I resemble that remark...

-Curly Howard

 

[C&K]

I have seen several Mercury 40's with bad center seal on the crank. The four-cylinder ones tend to break the aluminum seal carrier on the center main bearing. The twins like in this thread, the split seal ring on the bottom of the center main bearing goes bad with time, especially if the engine sat for a time without being properly winterized and the crankcase dried out. When that center seal goes bad they will still run but won't idle no matter how you tune it. The fours will tend to drop the two center cylinders at idle. The twins will run rough if the idle mixture is set rich enough. But the fix is to split the cases and replace the seals. While you got it apart may as well replace the lip seals on the crank ends too. I've done probably a dozen of 'em over the years.

 

[C&K]

I just did a parts lookup and that center bearing and seal is no longer available from Mercury Marine for the older Yamaha-made Mariner engines. There is none left in national stock. I suppose Brunswick couldn't support them forever, but it's still a shame. Those were actually pretty good engines in their day.

 

[BrounHownd]

I am not 100% familiar with that motor. Is the CDI a Yamaha or Mercury part?

Generally speaking, on yamaha stuff, the cdi's don't die. Or more specifically if there is a problem with them they just won't make a spark, hence the engine will never run. I have never (ever) seen one that would intermittently spark. Not that it doesn't happen, I just have never seen or heard of it, with yamaha.

Im going to give you a clue, hes full of doo doo and never replaced the CDI.

In way over his head with the knowledge base here and continues to flounder his way into further embarrassment.

In 5 days he cleaned both carbs, spent a day going to the lake and tested this work, ordered and recieved a new CDI and installed and tested this too. :lol:

On top of that, he synched twin carbs with no knowledge of what hes doing IN A BARREL NO LESS and wants us to believe its now running great due to his jet snapping skill set.

OP is now a certified YammyHammy tech, Believe it!

Or he'll put words in your mouth. :---)

You, sir, have contributed absolutely nothing to this thread beyond insults and negativity. Well, except for your vast knowledge of trash cans as the overarching solution to all of life's problems. It's not appreciated, and to be blunt, I'm a bit surprised that your actions and tone are tolerated by the moderators here.

To summarize, your involvement here has gone:

Me: Here's the problem.
You: You're an idiot, but I'm not going to tell you why. By the way you're an ass.
Me: Ok, thanks, trying diagnosis via the manual
You: If you're so smart, fix it on your own
Me: Ok. Thanks, I'll keep your trashcan input in mind when I get to that point again.
You: No one likes you, that's why no one is responding.
Me: Ok. I've seen some of the weird stuff you've suggested in the past, and you're not really offering any advice here, so yeah....
You: Read the service manual (Author's note--of course I read the damn manual, did you not read my other posts?) Also you: Me? Wrong? When? Can't ever happen
You: Har har, trashcan trashcan barrel harhar, I'm so awesome
Me: Clarifying that you inserted your own reality into my post
You: YOU'RE A LIAR
Also you: YOU'RE A LIAR, I CAN'T COUNT DAYS (seriously, where did 5 days come from?), I MAKE UP MY OWN STORYLINE SO I CAN MAKE FUN OF PEOPLE, I DON'T KNOW THAT PRIORITY MAIL EXISTS, I'M STILL OBSESSED WITH TRASH CANS, INSULT, still no useful contribution to the conversation

Seriously man, what's your deal?

I RTFM, followed the procedure written by the manufacturer, diagnosed an issue, replaced a part, took some useful advice from other users, and fixed the problem.

Why are you having such a hard time with that?

 

[BrounHownd]

I am not 100% familiar with that motor. Is the CDI a Yamaha or Mercury part?

Generally speaking, on yamaha stuff, the cdi's don't die. Or more specifically if there is a problem with them they just won't make a spark, hence the engine will never run. I have never (ever) seen one that would intermittently spark. Not that it doesn't happen, I just have never seen or heard of it, with yamaha.

Mercury, on the other hand, completely different story! Their electronics are, IMO, subpar. Another topic for another day...

if there were an erratic spark issue, or intermittent spark issue, a timing light would (usually) identify it pretty easily.

on any 2 stroke outboard the spark timing and carburetor have to be spot on. They don't "like" to be "off" much at all except for one or two degrees more advance up top (top speed) on SOME outboards. Most of the time the specified is perfect.

Again I don't know your outboard. On some of the older Yamaha C40's (twin carb twin cyl) it wasn't uncommon for me to have them show up at the shop with similar complaints from owners; who may or may not have had them "repaired" at another shop. Some things I saw. Jets cleaned with a drill bit or torch tip cleaner (makes the jet bigger). Carb passages cleaned with same manner (increases orifice sizes). Forgetting that there is a teeny tiny jet in the top (F25's specifically) and blowing the carb body out, the jet is lost; and it idles like poo. And the most common, forgetting to sync the carburetors and spark advance linkages after removal/reinstallation. The carbs themselves need synchronized, then sync the spark advance linkage to the carb(s). Carb sync is obviously not applicable on single carb motors but spark timing sync IS. Very common mistake. Not saying this is your issue, simply mentioning it.

Sometimes cleaning a carburetor becomes routine, you kinda just do it automatically and tend to forget the little details that normally aren't addressed. Like pulling the bowl, removing jets, cleaning, reassembling--and forgetting the atomizer tube, gasket, then the air bleed holes in the main body, and on some motors the prime start passageways and accelerator pump (which your ole 40 won't have). Even I have to remind myself that every situation is completely different, you MUST be thorough, or prepare to do it multiple times until it's finally fixed.

by the way when checking the timing, it may be wise (particularly on older motors) to verify that the pointer is actually correct. In other words, turn the engine to true TDC, verify TDC a second time, and make sure the pointer shows zero. I've seen a number of them off-some quite a bit (up to 10-12 degrees). Oh and I seem to remember a merc that had a sheared flywheel key, it seemed to run fine except low speed (retarded spark timing).

oil fuel mix. Some motors are designed to run 100:1 and guys will NOT do it, and then they gripe about idle quality. Well you're running twice the amount of oil through it so it's going to idle a little differently. Similarly, when fuel sits for a long time, it evaporates-but leaves behind the oil. So you mixed up 5 gal at 50:1 and in a few months you have 3 gal at 30:1, and the gas-is junk at that point. More 2 stroke outboard engines have experienced problems related to fuel and/or oil than any other problem combined. Again, not saying you have this issue-just pointing it out for those who might be web searching for idling issues.

There's been a time or two where I could not get them to idle properly, period. Normally it was due to a mechanical problem internal to the engine, whether it be water ingestion through a leaking gasket, low compression, leaking crankshaft seal, air leak between the block halves, air leak at the reed valve block, broken/damaged reed assembly, whatever. Those were pretty rare but again I did mostly yamaha stuff for the last 30 years, had about 4 years prior to that with Mercury. Mercury will keep techs busy. Yamaha? About like a maytag repairman. Sit on your thumbs waiting for the next carburetor cleaning to show up.

Thanks for all of this info! I did sync both the carbs and timing linkages according to the manual the first reply provided. Also, yes, checked TDC for sure!

As to the CDI, I don't doubt what you're saying, but what else can I say? I put the multimeter to it per the manual and every resistance measurement from the trigger wire was WAAAAY higher than the specs in the manual--and the boys that wrote that said if they're off to replace the component. Yes I cleaned the connectors and the probes.

I've heard about the 100 and 50 oil mixtures too--Mariner manual says 50 but I've also read similar motors with a Yamaha badge are spec'd at 100.

Anyway, had it out on the lake last Friday and it's damn close to being OK, at least in my opinion, for a 40 year old motor. It'll do for now until I'm on to the next project.

 

[RaisedByWolves]

I am not 100% familiar with that motor. Is the CDI a Yamaha or Mercury part?

Generally speaking, on yamaha stuff, the cdi's don't die. Or more specifically if there is a problem with them they just won't make a spark, hence the engine will never run. I have never (ever) seen one that would intermittently spark. Not that it doesn't happen, I just have never seen or heard of it, with yamaha.

Im going to give you a clue, hes full of doo doo and never replaced the CDI.

In way over his head with the knowledge base here and continues to flounder his way into further embarrassment.

In 5 days he cleaned both carbs, spent a day going to the lake and tested this work, ordered and recieved a new CDI and installed and tested this too. :lol:

On top of that, he synched twin carbs with no knowledge of what hes doing IN A BARREL NO LESS and wants us to believe its now running great due to his jet snapping skill set.

OP is now a certified YammyHammy tech, Believe it!

Or he'll put words in your mouth. :---)

You, sir, have contributed absolutely nothing to this thread beyond insults and negativity. Well, except for your vast knowledge of trash cans as the overarching solution to all of life's problems. It's not appreciated, and to be blunt, I'm a bit surprised that your actions and tone are tolerated by the moderators here.

To summarize, your involvement here has gone:

Me: Here's the problem.
You: You're an idiot, but I'm not going to tell you why. By the way you're an ass.
Me: Ok, thanks, trying diagnosis via the manual
You: If you're so smart, fix it on your own
Me: Ok. Thanks, I'll keep your trashcan input in mind when I get to that point again.
You: No one likes you, that's why no one is responding.
Me: Ok. I've seen some of the weird stuff you've suggested in the past, and you're not really offering any advice here, so yeah....
You: Read the service manual (Author's note--of course I read the damn manual, did you not read my other posts?) Also you: Me? Wrong? When? Can't ever happen
You: Har har, trashcan trashcan barrel harhar, I'm so awesome
Me: Clarifying that you inserted your own reality into my post
You: YOU'RE A LIAR
Also you: YOU'RE A LIAR, I CAN'T COUNT DAYS (seriously, where did 5 days come from?), I MAKE UP MY OWN STORYLINE SO I CAN MAKE FUN OF PEOPLE, I DON'T KNOW THAT PRIORITY MAIL EXISTS, I'M STILL OBSESSED WITH TRASH CANS, INSULT, still no useful contribution to the conversation

Seriously man, what's your deal?

I RTFM, followed the procedure written by the manufacturer, diagnosed an issue, replaced a part, took some useful advice from other users, and fixed the problem.

Why are you having such a hard time with that?

Blah blah blah, Im not even reading that.

You have made a fool of yourself, Im done with you.

 

[BrounHownd]

Im going to give you a clue, hes full of doo doo and never replaced the CDI.

In way over his head with the knowledge base here and continues to flounder his way into further embarrassment.

In 5 days he cleaned both carbs, spent a day going to the lake and tested this work, ordered and recieved a new CDI and installed and tested this too. :lol:

On top of that, he synched twin carbs with no knowledge of what hes doing IN A BARREL NO LESS and wants us to believe its now running great due to his jet snapping skill set.

OP is now a certified YammyHammy tech, Believe it!

Or he'll put words in your mouth. :---)

You, sir, have contributed absolutely nothing to this thread beyond insults and negativity. Well, except for your vast knowledge of trash cans as the overarching solution to all of life's problems. It's not appreciated, and to be blunt, I'm a bit surprised that your actions and tone are tolerated by the moderators here.

To summarize, your involvement here has gone:

Me: Here's the problem.
You: You're an idiot, but I'm not going to tell you why. By the way you're an ass.
Me: Ok, thanks, trying diagnosis via the manual
You: If you're so smart, fix it on your own
Me: Ok. Thanks, I'll keep your trashcan input in mind when I get to that point again.
You: No one likes you, that's why no one is responding.
Me: Ok. I've seen some of the weird stuff you've suggested in the past, and you're not really offering any advice here, so yeah....
You: Read the service manual (Author's note--of course I read the damn manual, did you not read my other posts?) Also you: Me? Wrong? When? Can't ever happen
You: Har har, trashcan trashcan barrel harhar, I'm so awesome
Me: Clarifying that you inserted your own reality into my post
You: YOU'RE A LIAR
Also you: YOU'RE A LIAR, I CAN'T COUNT DAYS (seriously, where did 5 days come from?), I MAKE UP MY OWN STORYLINE SO I CAN MAKE FUN OF PEOPLE, I DON'T KNOW THAT PRIORITY MAIL EXISTS, I'M STILL OBSESSED WITH TRASH CANS, INSULT, still no useful contribution to the conversation

Seriously man, what's your deal?

I RTFM, followed the procedure written by the manufacturer, diagnosed an issue, replaced a part, took some useful advice from other users, and fixed the problem.

Why are you having such a hard time with that?

Blah blah blah, Im not even reading that.

You have made a fool of yourself, Im done with you.

Finally.

But while we're at it, I do have to point out the irony of you giving me crap over damaging a carb jet. I damaged it, not snapped it off as you claim.

I think you're confusing that with one of your first posts here where you snapped off a bolt trying to perform some basic maintenance yourself.

So let's reel it in a bit next time around.

I'm a perfectly reasonable guy, but I'm not gonna take the kind of crap you've been slinging in this thread.

 

[thill]

Try spraying carb cleaner up around the flywheel.
You may have a leaky top seal. I had that issue, and it made me crazy until I found it, and then the engine ran smooth as butter.

 

[cyclops2]

We all did look for a THERMOSTAT & test it to be sure it is working correctly ?