TOPIC: Dam Maintainice Now What ?

My 115 Mercury was running good BUT ..I decided to decarbon her .Ive had this motor since 93 and have never done it read about brakeing rings ..SO I get a can of Sea Foam I mixed 1/2 the can to 3/4 a gallon of mixed gas .I ran her on the hose threw this mixture out of a 1 gallon can ..When the fuel was getting low I started to spray Sea Foam Deep Creep into the carbs while she was running I kept flipping between the 3 carbs till I killed it .I let it sit 2 hours and fired her up . Smoked like crazy and got some goop out the exhaust ..While it was hot I pulled the plugs and shot each cylinder with Deep Creep Hosed them down good .I put the plugs back in and let it set a hour .I fired her back up on Normal mixed gas , Smoked like crazy but when it cleared out it sounded better than its been in years .With GPS in hand I ran it hard down the river a few miles and she was running around 4 MPH quicker than last fall .On the way home she was flying then all of a sudden started to stammer then jump back to full power then stammer again after that it just started to fall on its face .I shut her down and started to check stuff . All seemed fine . Went to start it and No Go .CRAP ..Choked it No Go .I disconected the fuel line and tilted the motor forward .Hit the starter after sitting for awhile and it started to fire .Reconected the fuel lines and she ran but bogged and stammered .I stayed on the throttle and all of a sudden it caught and threw me back in the seat ..I got to the boat landing and shut her off .Restarted instantly when I hit the key .I did a couple of wide open passes across the lake and it ran super great .Ran half and 3/4 ran great Then I let it idle a minute or 2 then hit the throttle ..Stammer Scream Stammer Scream Stammer Scream and go like crazy Till I let it come back to idle . .Then it acted up again .I get home and pulled the drain plugs on the carbs . All three fuel ran nice . Checked the screen on the fuel pump it was spot less ..Check all the wires conections etc .. Everything seems fine .Then I looked at the bottom carb and saw a little something that was between that screen that blocks the front of the carb with the choke plate behind it . There was a piece of leaf in there .I pulled it out and fired the motor up and it idles good Hit the throttle on it and she was responsive .No load of course and on the muffs ..Ive never had one of these apart Is there a venturi in there that the leaf part could have been blocking and keeping it from getting Fuel ..?? Or maybe a idle circuit ..I hate to tear the carbs down for a leaf ..L.O.L..But I dont want to get stuck on the lake or fry a piston ..This motor has always run Flawlessly for the last 19 years .There is NO dribble at the carbs and when you squease the ball it shuts the fuel off well when the carbs are full ..IDEAS ???? I had a evinrude once where i wire broke inside the covering that went to thr srator It would cut off dead cold then come back on like you flipped a switch .By the way this is a Non Distributer Blue Band motor ..

Leaves from trees or other stuff ( mouse nests )that critters drag around can be sucked into the carburetors and hold the reed valves open.

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This stuff will get pulled thru and the motor will scream again. A leaf can block the " boost venturi " found on some carburetors.

did you change the plugs yet? they are prob fouled out...always put new plugs in after doing a seafoam treatment...

kajun wrote:

did you change the plugs yet? they are prob fouled out...always put new plugs in after doing a seafoam treatment...

I cleaned the plugs when I finished . When I took it to the lake it ran perfect .I made a few Wide open passes across the lake to Blow any louse carbon out I was suprised I had a power increase . I got another 4 MPH out of her than I did last fall .Could be other factors helping that to like weather but by the seat of my pants gauge she felt much strounger .Im always skeptical of Mechanic in a can stuff but she improved . Must have had carbon build up in there .
The lake goes to a river so I ran up the river around 7 miles and shut her down .When I restarted she took right off .Heading back to the lake she was running tip top then all of a sudden she would kinda flat spot and stammer for 5 seconds then jump back into running great .This went on for a bit and thats when I shut her down to check things .Thats when I tilted it up and let it sit for awhile .
This is on my CV16 .After some thinking last night seeing Im running a inboard factory fuel tank from 1975 and to stupid to put a fuel filter inline maybe im getting some fine rust up in there .When I let it idle maybe it gets in the neadle valve and holds her shut for awhile or I could have blockage in the tank .So Im gonna take her to the lake and run one of my plastic tanks on her and see if I have the same problem .

no you have to change the plugs after the WOT on the lake...its the WOT that fouls your plugs...I wouldnt just clean them either...I'd put new plugs in...

kajun wrote:

no you have to change the plugs after the WOT on the lake...its the WOT that fouls your plugs...I wouldnt just clean them either...I'd put new plugs in...

With all due respect if I run the boat Down the river for 5 to 7 miles at Wide Open Throttle and its running in the Mid 50s MPH and then when I slow down it ildes well and then run another 2 miles back before it goofs up But then starts again and hits the Mid 50s She aint got no fouled plugs .To hit the Mid 50s all 6 had to be fireing pretty well .Ive rarely seen a surface gap plug that fouled to the point where you couldnt dry the fuel off with a lighter Wipe it off and put it back to work .. What I know for certain is I pulled the drain plugs on the carbs today and used the squeaze ball to flush a bunch of fuel threw them .I then blew some compressed air threw the drain holes .and flushed again .I put a Fuel filter on with some new fuel line . I did notice that the O ring inside the quick connector looked kinda worn .Not having another around I pulled the line off the fuel pump and ran the fuel line straight to it .I fired it up and she sounded great .I took her to the lake . She fired up and idled great . Hit the throttle and it jumped up on plane like a bee had stung her in the butt and she hit around 53 on GPS .I made 3 runs across the lake each being around 4 miles .Between the runs ild shut her down and restart it . No problems .Ran her at 25 and 40 MPH on 1 trip No problems . I thought I had her fixxed . On the 4th run it started great but when I hit the throttle it started WOW Wowing sound and stammering . I hit the chokes to see if I could richen it and that only caused it to load up and stall .I got it restarted and cracked her open ..Stammer hit stammer hit . Back off the the throttle Stammer Hit Stammer Hit Then Jumped up on plane and Mid 50s again .Slowed back down and same crap then she would hit and get ..To me it sounds like the timing is way off till it hits a certain RPM or the spark breaking down .Ya ever had a car with a timing chain that jumped just a little .Or you had the Timing Way retarded When you crack the throttle open it will build RPM but fall on its face ?? Thats the way it acts till it catchs then it runs stroung as long as you dont slow down to much .Thought I heard these have a hi and low speed strator . Could one break down after it gets warm ?? Could one of the boxes break down after it gets warm ?? I heard some batteries will charge up to much and youll send to much voltage to the boxs or could a rectifier cause the battery to over charge and goof stuff up ?? Suppose I could check Batt voltage when its goofing ..Any Mercury Wizards on here ?? This is the first time she has let me down since forever ..

bobo wrote:

kajun wrote:

no you have to change the plugs after the WOT on the lake...its the WOT that fouls your plugs...I wouldnt just clean them either...I'd put new plugs in...

With all due respect if I run the boat Down the river for 5 to 7 miles at Wide Open Throttle and its running in the Mid 50s MPH and then when I slow down it ildes well and then run another 2 miles back before it goofs up But then starts again and hits the Mid 50s She aint got no fouled plugs .To hit the Mid 50s all 6 had to be fireing pretty well .Ive rarely seen a surface gap plug that fouled to the point where you couldnt dry the fuel off with a lighter Wipe it off and put it back to work .. What I know for certain is I pulled the drain plugs on the carbs today and used the squeaze ball to flush a bunch of fuel threw them .I then blew some compressed air threw the drain holes .and flushed again .I put a Fuel filter on with some new fuel line . I did notice that the O ring inside the quick connector looked kinda worn .I thought it might be sucking some air threw it . Not having another around I pulled the line off the fuel pump and ran the fuel line straight to it .I fired it up and she sounded great .I took her to the lake . She fired up and idled great . Hit the throttle and it jumped up on plane like a bee had stung her in the butt and she hit around 53 on GPS .I made 3 runs across the lake each being around 4 miles .Between the runs ild shut her down and restart it . No problems .Ran her at 25 and 40 MPH on 1 trip No problems . I thought I had her fixxed . On the 4th run it started great but when I hit the throttle it started WOW Wowing sound and stammering . I hit the chokes to see if I could richen it and that only caused it to load up and stall .I got it restarted and cracked her open ..Stammer hit stammer hit . Back off the the throttle Stammer Hit Stammer Hit Then Jumped up on plane and Mid 50s again .Slowed back down and same crap then she would hit and get ..To me it sounds like the timing is way off till it hits a certain RPM or the spark breaking down .Ya ever had a car with a timing chain that jumped just a little .Or you had the Timing Way retarded When you crack the throttle open it will build RPM but fall on its face ?? sometimes sounds almost like your hitting a Rev limiter . Thats the way it acts till it catchs then it runs stroung as long as you dont slow down to much .Thought I heard these have a hi and low speed strator . Could one break down after it gets warm ?? Could one of the boxes break down after it gets warm ?? I heard some batteries will charge up to much and youll send to much voltage to the boxs or could a rectifier cause the battery to over charge and goof stuff up ?? Suppose I could check Batt voltage when its goofing ..Any Mercury Wizards on here ?? This is the first time she has let me down since forever ..

bobo wondering what boat you have this merc on?

and also when using the seafoam deeo creep is that aerasol can with long straw? are u using that in the cyclinders too?
I have been using Blasters SET (small engine tuneup) which I think renamed to LMT (lawnmower tuneup), you can see Blasters other products on their website.

Bobo,
When the beast starts acting up - does it do any good to manually squeeze the prime bulb?
Sounds like this gremlin is really giving you the runaround.
Yes,...A component of this ignition could cause these symtoms.
I have attached the tests required to test the stator, trigger, & coils.
Hope these help.
If any of these tests suggest even a hint of possible cause - there are peak voltage tests as well that require a DVA meter and further spec sheets to test.
Thom

The Dr is in ... L.O.L..Thanks much ..Squeezeing the ball doesnt help .I thought it might be a fuel problem so I tried that .When I hit the choke when she was stammering it flooded it .So Im pretty sure ive got the gas getting to her .I was a GM mechanic for 10 years and a Body Man for another 8 .Outboards are a whole Different ball game for me .Same only Different ..L.O.L..This motor has given us Countless hours of Boating Pleasure Never a Problem . Still has Great Comprestion to .The only thing it did in the recent few years was sometimes after you started it for the first time of the day It would Stammer for maybe 5 to 7 seconds Then hit and be fine for rest of the day without problems .It wouldnt do it every time I took it out Just sometimes .So what happens here ?? When your stator coils line up it sends voltage to the Boxs then they basically Dump Juice to the coils ??

I didnt see the 115 6 clyinder on the chart unless im Reading it wroung .I should look up the year to .Its a Blue Band with No distributor , 6 coils and 2 Boxs ..

Sorry 'bout that,...I sent the 3-4 cyl pages.

Here are the inline-6, etc pages.
Thom