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Smoke!

C

CarlW

Member
Ah spring... hope I didn't screw up!
My tried & true 50hp Force outboard ('93 or '94) is now smoking out the water ports. Whitish-colored smoke. What's that mean?
It wouldn't idle w/out stalling so I put some seafoam/drygas and mixed fuel to it at a fast idle for about 5-10 minutes. No smoke for a little while, then smoke. I thought the smoke might be loose gunk and carbon fouling plugs, etc.
Pulled plugs and they are clean as I've ever seen them.
Motor starts right up even though smoking. It will almost idle on it's own. WTF? Thanks.
 
The poor idle might mean a carb cleaning is in order???
Top of the carb on the left side is a screw with a spring.
This is the air/fuel mix spring.
Try to turn it out just a bit and see if it helps the idle?
But first slowly turn it in counting the turns till it just GENTLY bottoms out. REMEMBER the turns.
That way you can put it back where you started if nothing helps??
The smoke could just be normal.
You sure it's not getting hot? Test the overheat buzzer.
The oil/ fuel mix at an idle is way too rich and it loads up with oil and smokes a lot.
Once it's ran at higher speed it will burn off the excess.
 
Thanks, I'll try the idle mixture. And yes, probably a carb teardown is necessary. Another forum where this is also posted said heavy seafoam treatment causes white smoke. I hope I didn't starve the motor of oil and now it's damaged.
I replaced the fuel with fresh mixed stuff and white smoke still present .
Someone also suggested water getting in cylinders causing smoke.
 
And I don't think motor is overheating. Water (and white smoke) arw coming out of the ports so its circulating. I don't have a working heat buzzer. Boat is in the water by the way.
 
You can use a car horn or any 12v horn to test the system.
The steam can be normal even on a hot day.
Both my Forces smoke and steam.
 
I tore my Tillotson carb down, gave it a rebuild kit and cleaned and compressed-aired everything. The carb looked fine inside, not a real mess or gunky at all. New gaskets installed, etc.
I put it back on and fired her up. Motor stars right up, but still won't idle. I have to keep throttle advanced almost all the way, Motor runs somewhat uneven and I know the rpms are not as fast as should be.
I did turn/screw in my mixture screw a bit... this helped smooth her out but she still won't idle.
White smoke is largely gone. Plugs beginning to blacken as normal (they were clean as a whistle after seafoam treatment.)
Anyway, I let her idle for a while...boat is at the dock and in the water. I managed to throw her in gear quickly and took a short ride (5 minutes). Motor ran much smoother under load and I had it almost wide open for a time.
I returned to the dock and to my surprise she idled long enough for me to tie her up, but I could tell she was struggling.
I shut her down and went to get more fuel as I was almost out.
When I got back, motor started right up but still won't idle.
Any thoughts as to what's going on?
Fuel pump?
I did notice fuel sometimes forms a drop on the underside of my fuel bowl and I think I saw fuel coming out of the front of the carb when first starting it.
Thanks for your suggestions.
Have not done a compression test as I do not have a tester. I have not tested the overheating alarm. Thank you.
 
Fuel out the front?? Could be: float not set right, bad float, broken reeds.
You need some kind of tachometer to set the rpm's right.
You also need a comp tester or a friend who has one.

You need to pull carb and check the reeds.

You can stop using Seafoam. It's a waste of $$$(my opinion) and doesn't remove carbon anyway.
Cheap dry gas does the same thing.

Fuel pump: does the squeezie get hard? Yes, it's probably ok.
A tear or hole wouldn't let the squeezie get hard.
Harbor Freight has economical equipment.
Comp testers are cheap.

The poor idle could be: sucking air around the carb, a bad reed, bad compression, bad air screw(taper on the screw is scored), air screw not set right, overheating,
low idle.
These are a few of the easier things to test.

The most important is the overheating system.
That can cost an engine.
 
Thanks Jerryjerry,
I think there was fuel coming out the front of the carb, but not much or for long, more like drips off the butterfly and some spray.
And yeah, I get it on the seafoam...that stuff just freaked me out by the smoke it caused. This thread should now be named "won't idle."
The carb float looked ok and sat level. Someone else mentioned a bad reed. By reed are you referring to part #31 on this page?
http://www.boats.net/parts/search/Merc2/Force/50 H.P. (1990)/507A90D/CARBURETOR/parts.html

My fuel bulb and line are new and the bulb stays hard. Boat starts RIGHT up, always has...

And I know it's not overheating. There's plenty of water coming out the back ports and the motor is not hot to the touch. In fact condensation was forming on the carb/manifold when it was running the other day.

I wonder if I should just try to get a new carb. Might be better than nickel and diming around with several parts.
But I will do a comp test first. Thanks again.
 
Just read another thread on here (carburetor issues) where the poster said gas running out the front of the carb. Jerryjerry had an insightful reply for me about needle valves: there are two types. I looked and seems the rebuild kit I got had a solid needle whereas my original was rubber-tipped. No wonder I had gas leaking out the front.
I put my old needle back in (looks in good shape) and the motor almost ran at full RPM. It surges and wants to but won't. No more gas is coming out my carb front though. And it still won't idle.... plan on getting the comp tester tomorrow.
 
The only reason to buy another carb is if you lost this one??
The pic you posted shows a carb not the intake where the reeds are.
http://www.boats.net/parts/search/Merc2/Force/50 H.P. (1992-1994)/0E000001 THRU 0E093699/parts.html
#11 in that diagram.
Good find on the needle tip!!!!!

Get it running, in the water and try adjusting the air screw.
Initial setting is 1 and 1/2 turn out.

Check the taper on the needle/screw. Needs to be smooth.

While it's running, try spraying starting fluid around the base of the carb and intake.
IF?? it makes the motor stall, stumble, change in anyway, then it's sucking air.

It only takes a minute to test the overheat?
The buzzer might be in the shifter???

Key on, ground the orange lead to anywhere on the block.
Should make the buzzer sound off.

Did you remove the welch plug on your carb?
Sometimes the plug leaks and lets in air??
Product called Indian Shellac . It's used to seal the plug and show if anyone tinkers with the carb??
 
OK, tinkered some more with her and I am still in the same boat, hehe ;)
And now I know what a reed is!
Did a compression test. Happy to report 130psi in each cylinder and they held that number without dropping.
I no longer have gas leaking out the carb front and no drops under bowl.
Taper on mixture screw is nice and smooth. I set it at 1 and 1/2 turns out. It seems to run worse at 1 and 1/4 out. No change between 1 and 1/2 and 2 turns out. I am keeping it at 1 and 1/2.
I did replace carb welch plug. I pounded in the dimple some to seat it and then cleaned and coated it with black RTV sealant. Hope that's an ok alternative. No shellac in my shop.
And I took your advice and sprayed ether around carb base and intake while running. No changes in idle or running habits.
Motor is cool. In fact carb has been condensating. I can touch the cylinder head, even keep my hand on it. Haven't tested the buzzer. A bit beyond my talents.

Some insights:
Top plug is blackening normally, while bottom plug is clean, a little too clean I think.
Not sure what to make of my current situation. Motor always ran great, tried & true.
Think a reed is still the cause? No vapor or smoke from carb mouth when shutting off motor.
 
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Setting the air screw: 1 and 1/2 out.
Start and get motor warm(preferably in the water)
Turn air screw in I/8th a turn until it stumbles/misses/stalls,wait 10 seconds for the carb to get used to the new setting.
Then when it stumbles turn the screw out 1/2 turn and leave it there.

Black RTV will fall off if fuel/oil gets on it.

Any auto parts store should have the Indian Shellac..
 
Jerryjerry05 said:
Setting the air screw: 1 and 1/2 out.
Start and get motor warm(preferably in the water)
Turn air screw in I/8th a turn until it stumbles/misses/stalls,wait 10 seconds for the carb to get used to the new setting.
Then when it stumbles turn the screw out 1/2 turn and leave it there.

Black RTV will fall off if fuel/oil gets on it.

Any auto parts store should have the Indian Shellac..
Click to expand...

Thank you, Sir, helpful advice...
I think another forum has lead me to the source of my trouble. Can read on "Eye" boats. Same title.
It is not a fuel problem after all.
I am only running on the top cylinder and do not seem to have spark to the bottom cylinder.
I guess I should have checked for spark long ago!
It's a learning curve!
I appreciate any help you can lend with ignition
Here's a pic of my ignition
 

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That motor is more likely a 87-91 the electronics are Prestolite.
Mercury started using their stuff on 92 and newer.

You know I usually start with saying do a compression and spark test??????????????

Try switching the coil leads around and see if the spark follows the change.
Then test the trigger leads and see if one isn't broken under the shrink wrap.
The leads are a very thin wire and break easily, usually under the shrink wrap.
Then switch the leads from the pack and see if it follows the switch. Yes? then a new pack is needed.
E-bay usually has good deals.
Then go to outboardignition.com to test the rest.
 
Hey, thanks!
Looks like a bad coil. I switched the coil leads like you said and spark went to other (bottom) cylinder.
I don't know what "trigger leads" are.
And thanks for the motor year range.
Checking diagrams for 1990 50hp shows my setup. I'll be ordering at least one coil. Probably should change the other too.
With fast shipping I might just be on the water for Memorial Day!
http://www.marineengine.com/parts/force-outboard-parts/50-hp-1990/507a90a/electrical-components
 
On the new, make sure the replacement is for a 50.
The plug wires are shorter on the other coils.
They Prestolite coils are the same just the wire is longer for the 50.
 
Jerryjerry05 said:
On the new, make sure the replacement is for a 50.
The plug wires are shorter on the other coils.
They Prestolite coils are the same just the wire is longer for the 50.
Click to expand...


I'm back on the water, folks... You could hear my cry of triumph from across the lake!
Jerry, you know your stuff. Lesson learned on wire length...
I bought a pair of aftermarket CDI coils (from the host of this forum) but I could only utilize ONE due to the plug wire length.
I don't believe there is an option for ordering these by HP size. Says fits "most" 1987-1992 (50, 55, 60, 80, 85, 90, 115, 120, 125 & 150 HP)
The top cylinder wire is adequate, but you're going to need another wire for the bottom cylinder on a 50
I happened to have an old wire from a car kicking around, but the terminals didn't grab too good. I couldn't make it work.
I ended up having to put one of the old coils back in.
Which has me baffled: either one of the new coils is bad, OR it needs a new and right length wire.
But my old wire operated the new coil on the top cylinder just fine.
I plan on calling Marine Engine on Tuesday.
Coil description here:
http://www.marineengine.com/newparts/part_details.php?pnum=CDI182-4475R
 
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You CAN splice the coil wires together.
You just need to cover the splice REALLLLY good.

I use shrink tube and then another shrink tube and then liquid electric tape(2 coats)
 
Jerryjerry05 said:
You CAN splice the coil wires together.
You just need to cover the splice REALLLLY good.

I use shrink tube and then another shrink tube and then liquid electric tape(2 coats)
Click to expand...

You mean PLUG wire, right?
Yeah, maybe I'll do that.
I remember when local parts stores would make you a plug wire set. Seems those days are gone. I even checked with the largest marina in my area and they couldn't help. Not even a single wire? They just gave me a part # (that they didn't have in stock).
Anyway, what's more troubling is that I couldn't get one of the new coils to work (to power a cylinder). And I know that old wire I found works. Do you know of a way to test these coils without the hassle of re-installng? Can an auto parts store do it?
 
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The manual says: IF?? all the other components are good???
Then the coil MUST be bad.

In the OLD days they had a meter that could test coils.
I haven't seen one of these in 15years.
 
Jerryjerry05 said:
The manual says: IF?? all the other components are good???
Then the coil MUST be bad.

In the OLD days they had a meter that could test coils.
I haven't seen one of these in 15years.
Click to expand...

Hi Jerry, to follow up...
I sent what I thought was the bad coil of the new pair I bought back to the manufacturer (CDI).
They sent a new one (seems one of the pair WAS bad after all).
I also mentioned my situation with the short plug wire on a 50hp
I got another short wire with the replacement coil. ???

Called CDI and they are sending another wire, but the only other wire choice is 24 inches, way too l o n g....
Seems only wire choices are 16 or 24-inch. I need a 18 or 20 for bottom cyl.
Anyway, this whole thing is a lesson on wire length if one needs a new coil on a Force 50 ('87-'91)

I'm pleased with the service from CDI.
Thanks for your help, Jerry!
Be talking to you again, I'm sure!
 
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