Mercury problems

[jonkidd]

Hi, I inherited a mercury 50 hp 3 cylinder 2 stroke . I believe it is a 1987 model and the only number I can find is on the freeze plug B148283. There has been other people working on this boat. Carbs cleaned , new fuel lines etc. When I got it the 1st thing I did was check compression 120,121,123 . Next I checked for spark no spark. Pulled flywheel and noticed the yellow wires coming out of stator insulation was wore off. I checked power out from stator to power pack and it was producing power I have spark Yes But it will not rev to full power. I pulled the carbs to clean and found plastic connection to bottom carb was broken Bought new pulled off bottom only carb bowel it was very clean inside. Reinstalled carbs with connection and verified both carbs open up in sync. Plugs are black and sooty when I pulled them also see water leaking around spark plug holes on out side of head. Runs better Starts easy But when I get it full power it seems to bog down. At 3/4 power seems to run better than full power. Here is a link to a video I just made. See how bottom carb is spraying more fuel than the top carb, and at WOT (wide open throttle) it is much more fuel . https://youtu.be/2m_RRGFZBow Thanks for the Help

 

[flyingscott]

That carb looks like it may need to be rebuilt. There is no head on that motor only a water jacket so that's an easy fix just replace the gasket.

 

[jonkidd]

Sorry for the delay,

I will order water jacket gasket this week.
Adjusted the fuel needles, Set float , and was able to get carburetors working correctly .

The carbs were both super clean. I put a timing light on the motor and fired it up. As I was shooting the timing light on the flywheel I noticed it would blink well on idle but when I throttled it up the the timing light would blink ( kind of erratic) . So I tried each cylinder and number two seems to be o.k. but 1 and 3 are erratic. Also as the timing light flashed, throttled up, I could hear a change in motor rps( faster)

I did mark number one TDC but can't find timing marks Anywhere on this motor.
So I marked each cylinder TDC and put 1,2,3 markings on flywheel.
This is a bolt on flywheel so a crankshaft key way does Not come into play.

Hope makes sense. I can post pictures or link a youtube video.

This one has me stumped.

Also I hooked the timing light to a riding mower and it ran fine and as throttle increased the timing light strobes in sync . So My old timing light is working correctly.



Also got a pfd service manual . But it doesn't mention timing marks in relation to flywheel and motor Anywhere.

I found a test for mercury coil packs here ( I have been reading a lot good info on here) and will try that tomorrow . http://forums.iboats.com/forum/engin...y-mariner-coil

Thanks For Any help

Sorry if my grammar is horrible
Jonkidd

 

[flyingscott]

Make sure the timing light pick up is not by any of the other wires it will pick up the signal from them. That will make them read erratic. Have you cleaned the carb and/or fuel pump or did you just look at them. Leave the timing alone for now.

 

[jonkidd]

I cleaned both cabs and jet ways. I adjusted the float level on the carb that seemed to be spraying too much fuel to match the other carb. Checked the bowl needles , they seat good . Pulled both jets in the carbs and cleaned, they were not gummed up I pulled fuel needles out and inspected and put them both in then adjusted to 1 and 1/2 out. The timing light wires did go near the new power pack. I will route them to the other side tomorrow and test again.

I did take it to the lake earlier and the boat pulled good but would not plane out. Was quick to move but never planed

The fuel pump I never looked at.
The primer bulb does not ever get hard.

But motor fires up Very good and had it running over 30 minutes and never dies.
I also sprayed carb cleaned around the case to make sure no leak there, no increase or decrease in rpms.

Plugs are black and wet in number 1 and 3
Number 2 Plug has very little soot.

Also When I tilted motor after the lake . I did see water bubbles in the fuel that ran out of it when it was tilted all the way up.
I just put Fresh Non Ethanol 50 to 1 93 octane in the other day. So I assume the fuel is good.
Will test the tank tomorrow.
(( A clear glass mason jar and water will settle to bottom ( old school ways))




Is it possible the fuel pump may be sucking in water via crank case?

I've done my home work on this one and need you to school me

Thanks Again I Really appreciate your time

 

[flyingscott]

If the spark was erratic highly doubtful it would run smooth at all. Go to www.cdielectronics.com to find the test procedures for your stator and box. Timing light pick ups when you put them on the spark plug wire if they hang by the next plug wire they will pick up the signal from it.

 

[flyingscott]

If the primer bulb never gets hard that can also be an issue. Bad bulb in the fuel line or a bad needle and seat or waterlogged float.

 

[jonkidd]

Changed the cdi,trigger,coils,spark plugs, re-cleaned the carbs. And plugs 2-3 miss at high rpm. See video please. Thanks for all your help this one is driving me nuts.
https://www.youtube.com/watch?v=MDjI...ature=youtu.be

 

[jonkidd]

https://www.youtube.com/watch?v=UMTJ_QiLh44&feature=youtu.be

 

[jonkidd]

Update 4/20/17

Rebuilt fuel pump . Primer bulb is now getting hard.
Installed a new stator. Per cdi instructions. WTH. It is doing the same Exact thing. SMH :rant:

Maybe I will just use the trolling motor so I can :fish2:

Not sure what to do next.
:help:

 

[jonkidd]

:bounce:Figured it out. Runs like a champ now. The new cdi or if you prefer Power pack was defective. I contacted the company and they said it had a 1 year warranty. Sent me a another one. This boat is fast . Love it. Took it to the lake twice already and with 3 people it hauls butt. Thanks for the help time to go island camping
:usa2::usa2::usa2::first:

 

[jonkidd]

SOLVED

Hi, I inherited a mercury 50 hp 3 cylinder 2 stroke . I believe it is a 1987 model and the only number I can find is on the freeze plug B148283. There has been other people working on this boat. Carbs cleaned , new fuel lines etc. When I got it the 1st thing I did was check compression 120,121,123 . Next I checked for spark no spark. Pulled flywheel and noticed the yellow wires coming out of stator insulation was wore off. I checked power out from stator to power pack and it was producing power I have spark Yes But it will not rev to full power. I pulled the carbs to clean and found plastic connection to bottom carb was broken Bought new pulled off bottom only carb bowel it was very clean inside. Reinstalled carbs with connection and verified both carbs open up in sync. Plugs are black and sooty when I pulled them also see water leaking around spark plug holes on out side of head. Runs better Starts easy But when I get it full power it seems to bog down. At 3/4 power seems to run better than full power. Here is a link to a video I just made. See how bottom carb is spraying more fuel than the top carb, and at WOT (wide open throttle) it is much more fuel . https://youtu.be/2m_RRGFZBow Thanks for the Help