too rich

solar7647

solar7647

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Re: too rich

I don't think your spark is the problem, is the spark blue or more orange? My experience with black smoke is burning to much fuel. I would say check you your fuel line for clog and you fuel filter, then put power to just pump to make sure your getting good flow.... Also take the flame arrestor off the carb and manually pump the throttle linkage so you can see the injectors in the carb and how they are squirting the fuel in. Also verify your air fuel mixture screw are set properly. Turn them all the way in till they stop, then turn them out one full turn them another half. Then start it up and see what you get. If your not getting a good air/ fuel mix ie to much fuel vs air could be the issue. Let us know what you find.
 
achris

achris

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Re: too rich

Let's go back to basics. Have you done a compression check?

Chris.....
 
C

cdiamond

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Re: too rich

c'mon guys

this is toooo.... easy

carbed engine, running rich when cold ... duh

it's called a CHOKE
 
Last edited:
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FishHog

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Re: too rich

cdiamond said:
c'mon guys

this is toooo.... easy

carbed engine, running rich when cold ... duh

it's called a CHOKE
Click to expand...

ruled that out, by holding the choke wide open and same issue. Then a complete second carb, and same results. Its electric choke, opens when it warms, but holding it open and I'm still getting the same thing.
 
MikDee

MikDee

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Re: too rich

What is a TKS?
Someone on another forum had similar trouble, only to find a sticky TKS piston, due to a little burr on it,,, he fixed that, and all was fine!
 
achris

achris

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Re: too rich

TKS = Turn Key Start... It's a carb with an enricher rather than a choke flap. The enricher operates much like a choke in that an electric coil heats up to 'dis-engage' it... As OP has now talked about 'holding the choke open', it ain't a TKS....

Chris...
 
achris

achris

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Re: too rich

OK.. Compressions good. Carb adjustments good, fuel pump pressure good. Could a weak spark do it? Maybe, but I would also expect some missing, and hard starting. Timing out, maybe, but again, other symptoms that you are not seeing. And the smoke is definitely black, not blue. Silly question... Spark plugs... Right ones (NGK BPR6EFS or AC MR43LTS) and gapped to 45 thou (1.1mm)...

Chris......
 
MikDee

MikDee

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Re: too rich

achris said:
TKS = Turn Key Start... It's a carb with an enricher rather than a choke flap. The enricher operates much like a choke in that an electric coil heats up to 'dis-engage' it... As OP has now talked about 'holding the choke open', it ain't a TKS....

Chris...
Click to expand...

Thanks for the clarification Chris
You are the "go to" Guy ;)
 
eavega

eavega

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Re: too rich

achris said:
OK.. Compressions good. Carb adjustments good, fuel pump pressure good. Could a weak spark do it? Maybe, but I would also expect some missing, and hard starting. Timing out, maybe, but again, other symptoms that you are not seeing. And the smoke is definitely black, not blue. Silly question... Spark plugs... Right ones (NGK BPR6EFS or AC MR43LTS) and gapped to 45 thou (1.1mm)...

Chris......
Click to expand...

I had my Mercruiser 3.0l last year blowing tons of black smoke, really hard to start, and hard to keep running. This was after I converted my ignition with the Pertronix kit. Turns out the timing went all out of whack. Don't know if that is it, but I'm just sharing my own experience.

Rgds

Eric
 
F

FishHog

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Re: too rich

achris said:
OK.. Compressions good. Carb adjustments good, fuel pump pressure good. Could a weak spark do it? Maybe, but I would also expect some missing, and hard starting. Timing out, maybe, but again, other symptoms that you are not seeing. And the smoke is definitely black, not blue. Silly question... Spark plugs... Right ones (NGK BPR6EFS or AC MR43LTS) and gapped to 45 thou (1.1mm)...

Chris......
Click to expand...

Yes 43LTS at 0.045. Fouled the first set up and had to switch them to even get it to start again. Yes definitely black, I paid a lot of attention to it yesterday and its as black as black can be. the shrub behind the prop exhaust now has a lot of carbon on it. I am getting very hard starting, but when it won't start the plug are wet with fuel, so I know its flooded. Once running, it runs great, minus the smoke. had it on the water the other day for a good 45min cruise and it does not miss at all.
 
achris

achris

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Re: too rich

Have you checked the timing?
 
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FishHog

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Re: too rich

did the timing last season, and it was fine (according to my mechanic buddy), had the same issue, but not quite so bad. But I'm borrowing a timing light to check again tonight just to rule it out. Distributor was tight, so I can't see how it could have moved from last summer, but will verify.
 
MikDee

MikDee

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Re: too rich

Is there something in the exhaust that's clogged up! Like a banana in the exhaust pipe? :D Seriously, stuck Flappers?
With a cold engine, this would be most noticeable! If the fuel can't get out, I would think it would back up into the engine!
 
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FishHog

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Re: too rich

MikDee said:
Is there something in the exhaust that's clogged up! Like a banana in the exhaust pipe? :D Seriously, stuck Flappers?
With a cold engine, this would be most noticeable! If the fuel can't get out, I would think it would back up into the engine!
Click to expand...

Interesting thought. Can't see it, but I guess its worth a check. Replaced the flappers 2 years ago, But I guess I could pull them for a test to see if it makes a difference.
 
solar7647

solar7647

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Re: too rich

Just as a thought....what kind of fuel are you using? Do you get it from the same place all the time? Was there anything that happened before this started...like did you do an oil change and then this started or something like that?
 
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FishHog

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Re: too rich

no, nothing. Well I did an oil change last fall before I winterized it, but that's not really a change. Have done lots and although its flooding more now, it has smoked and caused this issue for some time. I'm sure its not fuel related, but I might plumb in a fresh separate can of fuel just to rule that out.
 
solar7647

solar7647

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Re: too rich

OK, 2 things, have you double checked the timing as suggested by others? If so what is it? Also have you checked to make sure fuel line is clear of cloggs and well as the filter.

Check the position of accel pump as illustrated in the photo, if your carb is equiped with the 3 hole lever, see what reduceing the accel pump stroke does, maybe an adj hear will help.
accel pump.jpg

Also check the position of the choke as shown in photo below, and adjust to position it shows if not already.
choke.jpg
 
solar7647

solar7647

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Re: too rich

Also make sure that the float in the carb is good.
 
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