4200 RPM

[stuartsx5]

I have had my outboard worked (1996 Force 120) on and I am still not where I need to be.   To start it was running fine, 5000 WOT at about 40 MPH and it just dropped to 4200 and 35.  Took it to a mechanic, said coils bad, replaced with used ones he had. Said fuel line deteriorated, plugged the carbs, so the carbs were cleaned.  Got it back and would do about 4600 and about 38 MPH.  Thought it may be the instruments but didn't seem exactly right.  Three weeks ago, running down the lake and dropped rpm and mph just like last fall.  Low end rpm so bad I couldn't even load it on the trailer.  Took it to the mechanic he adjusted carbs so the low end is better but hole shot and top end speed and RPM still not where they should be.  So, this is my question.  Should I be looking at ignition first or fuel?  Is there anywhere I can have the coils load tested?  I hate to replace without testing because I think that is what has been done. I am at the end of my rope with this and it is about time to start pulling skiers also and it wouldn't do that very well in the shape it is in. HELP......... Fishnwrench, are you accepting new patients???????? 

[fishinwrench]

The '96 Force 4 cyl. has the CDM module coils.  No bench test for them, and if your mechanic had some "laying around" then they are probably bad.  Merc has only "improved" them (and superceded the part#) about 14 times.     I would gladly take it as a new patient, or I could give the mechanic closer to you some tips on getting to the true issue.....since it sounds like he is chasing his tail and/or has missed a few "service bulletins" on the CDM ignition system.   

If it is truly an ignition problem then he needs to verify stator and trigger output, if they are within spec then replace all 4 CDM modules (coils) with THESE...   

http://www.marineengine.com/newparts/part_details.php?pnum=CDI114-7509

Do not replace with any of the  Mercury #827509A1, A3, A4, A7,A9, A10, or T7  

Test the voltage regulator.

And be sure the correct spark plugs is used......which should be a Champion QL76V and not the NGK BUZHW that is in almost every 4cylinder Force that comes in here... because that's what happens when people shop for spark plugs at automotive outlets. 

[stuartsx5]

Thanks Wrench.  If I am going to start replacing parts I assume I would be best to start with the plugs because I replaced them last fall and I did use the NKG plugs right before the trip that started my problems.  Could that be the problem or a small part of the bigger problem.  Since there is no bench test for the coils do you use a resistance test with an ohm meter?  That is something I can do if I know what terminals and what the readings should be.  I may look into those two issues and the voltage regulator and if I can't figure it out or that doesn't fix it I will set up an appointment for you to take a look at it.  Thanks Again.

[176champion]

Couple questions..but im no expert on outboards but know enough to be dangerous....Did he rebuild the fuel pump since the fuel lines where deteriorated? You said he had carbs off to clean out did he do a proper link and sync when he put carbs back on and one other thing do the butter flies open up all the way when throttle is wide open? Other wise i would let Wrench put his magic touch to it.

[stuartsx5]

He did mention the fuel pump but he thought it was ok.  I wouldn't know about the link and sync because I know absolutely nothing about carbs on outboards or any other engines.  I can check the butterflies (I assume those are the flaps inside the intake part of the carb).  I may do that tonight.  I'm not going to put too much effort into it before I go see Wrench cause I can probably tear up more than I fix with my limited knowledge.  I have been very fortunate over the years and have bought old boats that just run forever.  This is the first time I have had to even consider a mechanic.  Thanks for your input, I will keep you all updated on my escapades.

[fishinwrench]

Fuel pump tests are easy, first pull one side of the pulse hose (or remove the pump if it is one that pulses through a port on the back), pump the primer bulb up tight and see if any fuel exits the pulse port.  If it does there is a leak in the diaphragm.   If not then reattach the pulse port, start the motor and disconnect the fuel supply hose, let the motor idle until it sounds like it is about to run out of fuel, reattach the fuel supply and see if the motor picks back up.    If it passes those two tests then the fuel pump is ok.  

[stuartsx5]

Thanks Wrench.  Sounds like I have a full weekend of testing to do.  Maybe momma needs a new boat for Mother's Day......😊

[stuartsx5]

So, I have been piddling around with this tonight. Pulled the plugs, seemed like all were grimey except one. Pulled the carb covers off. I don't know much but I assume the top carb (see pics) has the choke plate but not the bottom one? So, in the side picture it shows nothing attached to that choke plate so when I choke it I can hear a click but nothing happens. I know this has nothing to do with my problems but is that wrong or does it choke some other way than that choke plate?

[fishinwrench]

Frankenstein !    The top carb is not original equipment, someone has swapped it for one off an older model...but used the original carb bowl to feed the enrichener.

The clicking you hear is an enrichener solenoid.  The motor did not come factory with a choke plate.     

Measure the Venturi of the 2 carbs and see if they are identical in measurement.  

[fishinwrench]

See the idle mixture screw on the bottom carb?

Look at carb #1....... No idle mixture screw.   Where is it?

It's gonna take some CSI detective work to figure out who did what here.  This is like the motors they threw at us during training.  God only knows what's been jacked with and shade treed. 

The lock washers are missing from the carb mounting flange also.  Those are there for a reason, not spare parts.

Sorry if I sound cranky.  Crap like this is rediculous.  In this business you have Techs, Mechanics, Parts changers, .....and guys that should only work on lawn mowers and bicycles.