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I need an Expert! Please Help

T

toqwik

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I have spent the entire summer fighting this engine. Here is entire story. Motor ran awesome 5 years ago. Motor was pulled and kept in dry storage while boat got floors, transom, etc. put motor on. Compression 120-125 all cylinders. 1987 Mercury 115 tower of power. Reinstall. Fire it up. Runs a little sluggish on the hose. Probably needs a carb job. Do carbs, no spark. Troubleshoot no spark to trigger. Stator was original so replace them both. Now intermitten spark, some cylinders yes some no. Put new switching g boxes on it. Now pump up ball. Hard start. Hits quick and disengages starter. Has new correct anti fouling plugs. Once it finally starts idle kinda rough. Moving the high speed lever (shifter does not allow for throttling when not in gear). It will slowly idle up. I can put it in gear and rev it, it’s slow but will get there. Put in the water and it will barely move, I would guess less than 2000 rpm. Can put my hand over each carb to choke out and can pull fuel. Try to throttle up and it sounds like an old Quadra jet and bogs and dies. Local shops are at least 6-8 weeks out. Talked to a guy today. My thought was timing. He said it should run better than it is even if it’s off from the trigger replacement. He asked about mud dobbers and there were a few under the cowling. He thinks maybe a nest in the exhaust. I have never messed with the fuel pump. I put a new water pump in it but didn’t look up inside for nests. Someone please give me some good avenues to chase. Also running of a 6 gallon tank with fresh fuel. New primer bulb and all new fuel line. Removed the quick disconnect from the motor and goes straight from tank to pump with a new inline clear filter. Thanks for your replies.
 
Sounds like the same situation that I'm in with a 1985. Did you notice my post? Pappy suggests trigger unit defect. He is perhaps the sharpest guy here on the Forum regarding the "towers". On my project I replaced the trigger, the stator, and both switch boxes. Did you buy components from CDI Electronics or original equipment? I never attempted to start this motor because my spark testing showed very intermittent and unpredictable spark. You need to do a spark test and with all the cranking you should provide some water with the garden hose. I never suggest attempting to start a motor unless you are CERTAIN of deliberate and reliable spark. Click below for my post on the same subject.
http://www.marineengine.com/boat-fo...rc-90-quot-Tower-quot-bad-unpredictable-spark
 
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I have not checked flow out of fuel pump but that is a good idea. My local shops all showed the trigger discontinued so I went with CDI. I have never had an issue with them but there is a first for anything. I will read your post, I need to wrap this thing up. Thanks for the replies.
 
Yes we may have gotten a couple bad triggers from CDI. I have been repairing and sales of outboard and marine equipment for over 50 years. It's usually the electronics that "kick you in the crotch". Everything else is quite "predicable"...... appeal to "Pappy" here again.
Question for you.....how did you determine it had no spark after the carb rebuilds?
Question for Pappy....or Racer....or Gator....Mr. Scott.....Mr. Reeves (wherever you are).....any experienced tech.....will a defective trigger "take out" new switch boxes? I say yes....If this trigger checks bad.....CDI should replace the new boxes too. That magneto Mark 30 behind me....never failed in 35 years of continuous WOT......????? Huh?
 
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I have a guy that always rebuilds my carbs for anything I am working on. Boats, cars, whatever. He is older and was being less than kind for me when putting the carbs back on. He moved the plate from infront if the carbs when he was trying to get the carbs on and was being rough to me with it. Once back together and wouldn’t start I started checking things a found the box that bolts to that plate, I think it does something with timing at low idle, the large red wire was burnt and broken. Kinda wonder if that is what took out my electronics. My brother in law is an electrician so we tested by the manual and I want to say he said it should be a pulse to the control boxes but there was no pulse. That’s how we troubleshot the motor. I ordered both boxes just in case I needed them and I did need them. My name is Scott and I am a hobbyist far from a tech. I have been running the mercury and mariner tower of powers since they came out and have never had a problem with one. Tilt/trim motors is about it until now. I hate to take it to a shop but it’s looking dim to me. I want to run this boat so bad.
 
Seems the other techs here rarely answer my threads....guess they expect me to know more than I know. Well guess what? I'm getting to the point where I spend more time looking for my glasses, than fixing motors. I learn one thing.....but forget two things......I think it's gonna be a "long ride out"!
 
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I had a guy consign a boat for me a few months ago, nice guy. I’m taking it to him to figure out. Said it will probably be a few weeks but his mechanic, older guy who likes these motors, will figure it out. I have spent way too many hours in the Florida sun this summer fighting it and I might not figure it out in a year. I am joining the throwing i. The towel club. Bet it’s gonna be something simple. I will update you all once I figure it out. Now to my free boat from the neighbor. Maybe get it in the water this weekend.
 
Good...I might have the answer sooner for you, just gotta get back up to Island L. here and do some testing. The owner has been too busy to have me work on it. I think that "Pappy" could figure it out in 2 minutes.....but he isn't here.
 
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