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25 Horse Starting Problems

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boondog

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"Hello all, first post. I am n

"Hello all, first post. I am new to the boating world and recently picked up a 1996 Bass Tracker with a 25 horse Merc 2stroke on it. I sat recently but it was last year. I thought I had stored it correctly. Fogged the motor and put fuel stabilizer in the tank. Wrapped it up tight to keep water out. This last week I pulled it out and put the motor flusher on it and primed the motor a few times and she coughed a bit and fired right up. It smoked for a few minutes (fogging oil) and the water pump was working well, nice strong stream. Installed the new prop. My buddy and I figured all was well. Went off to the lake, did not put any fresh fuel in the tank. Got on the water and she started right up, idled nice. We took off downhill (15 mph tailwind) and got about three or four hundred feet and she coughed once, then it sputtered and stalled. Started back up and died again. Continued doing this til it refused to start at all. We were in the middle of the lake and seeing as how we were in the middle of the lake, we fished. Well that wind started getting worse and our anchor was slipping, unbeknownst to us. Well, I think we just hoped it would start magically for us. Nope. Wound up using the trolling motor the whole way back up hill, cold and raining and windy. Now on the return trip, our main battery died and we wound up just pulling all electrical off the batteries except for the trolling motor. Made it back to the trailer.

Flash forward to this past weekend, we put the wiring back together but it seems we got the starter wires crossed somehow and had tried the starter in reverse a few times. The wiring is normal now and the motor spins like a champ and with the flusher it has water from cranking from the pump. We drained the tank completely and put in fresh fuel with a good TCW-3 oil and stabilizer and no dice. We pulled the plugs and they look awesome and are definitely getting plenty of fuel, wet. We tried checking for spark and could not find any. We are very experienced car mechanics and can rebuild auto transmission without sweating but we don't know where to start on this. We checked all the fuses we could find and they all are good. The inline fuses on the wiring seemed good as well. Can anyone help me get my outboard running again? I really miss fishing.

Thanks in advance

Motor specs
1996 Mercury 25 Horse 2 stroke (classic I believe)
Serial number 0G288618.

Checking for ohms,
Stator -
Red/Black measured 141 ohms (spec at 100-180)
Blue/Black measured 3.15 ohms (spec at 29-35 X100)
Red/Blue measured 3.01 ohms (spec at 28-34 X100)

Trigger - (Brwn/Wht)/(Brwn/Ylw) .762 ohms (spec at 6.5 - 8.5 X100)

Coils - (positive disconnected)
Upper -
Across terminals .3
Boot to terminal .938
Lower -
Across terminals .3
Boot to terminal .933

I have had suggestions of a bad stator, so I replaced it. Got a good deal on it. Installed that and had no difference. Any ideas as to what it might be?

Thanks for any help you can offer."
 
Disconnect the black wire with

Disconnect the black wire with the yellow tracer from the switchbox (should be on the lower left as you look at the switchbox - if you follow it from the bullet connector at the switchbox it will tee off under the powerhead - it's connected to the kill circuit) and see if you get your spark back.
 
"AH Graham,that slipped my min

"AH Graham,that slipped my mind
blush.gif
"
 
I will try that and report bac

I will try that and report back. I hope to have it operational soon. Missing the season kinda stinks.
 
"Okay, so we tried disconnecti

"Okay, so we tried disconnecting the black/yellow wire and it did not start. We then decided to go back to basics and checked the fuses, again. We found a 5 amp fuse which was blown (orange). We replaced it and with the black/yellow wire disconnected, it still did not start. We then reconnected the black/yellow wire and the fuse popped again. We then had the key in the off position and replaced the fuse and heard it pop as soon as it was put in. We don't know what this fuse goes too, we are gonna try and trace said wire. It clearly has something to do with that black/yellow wire and/or the kill switch."
 
You've got a direct short

You've got a direct short somewhere. Look for a frayed wire touchiong metal.

Jeff
 
"Okay, we have diagnosed the s

"Okay, we have diagnosed the shorting wire. It was a bad courtesy light
blush.gif
. Since that is straightened out now, we decided to check the deadman switch directly. It checked out good, having continuity when off, and no continuity when on per the FSM. We then checked the ignition switch as well. All the continuity tests checked out good per the FSM. We ran the tests on the stator/switchbox/trigger/coils. Everything looked okay. The coils resistance across the terminals checked out at .3 each, which is higher than the spec set, is this too much resistance????

We also ran the trigger tests and got 757 ohms which is perfect in the specs.
The opposite side (switch box side) measured at 3.97 if that helps.}

FWIW, this motor never seemed to have the power it should have. It never really wanted to rev past 3000 - 3500 rpm. It never really bothered us as this is our first boat and it got us out there. Now we are wondering if this is the start of our problem and we did not really notice it. Out of the water, with a motor flusher on, it would rev right up with no problems. Can anyone shed some light on our problem, please?"
 
"That may have been true, but

"That may have been true, but we had tried a smaller prop which was the reccomended prop from the website. Either way, the motor needs to run first. We just bought a DVA meter to start digging further. Any help you can give, even if it is that you are out of ideas, is helpful. TIA!"
 
"Its a 17ft Bass Tracker. Not

"Its a 17ft Bass Tracker. Not enough motor, I know. But this thing bogs badly, we got passed by a pontoon boat with a 35 on it! I can get it to maybe 12 or 15 mph and thats it."
 
A 17 footer? Cripes! You need

A 17 footer? Cripes! You need at least 75 hp on that rig. No wonder the poor thing is bogging down.

Jeff
 
"I'm impressed it's ev

"I'm impressed it's even getting 12-15 mph, a 25 on a 14 footer (total load of about 850-900 pounds, including the boat/motor/people and junk) would only see the mid 20's on a calm day.

That motor is overworking like crazy and is in real danger of experiencing detonation issues and totally blowing the powerhead to pieces.

Now, if you move it over slightly to the left or the right and hang another 25 on the back to keep it company you would probably be close to the (required) minimum horsepower for normal use on that boat...

For a boat to function as it was intended, according to the design, you should power it with 80% of the max horse rating (so if rated for say 90 horse - 90 x.8 = 72 (rounded to 75 horse))

Anything less over works the motor, anything more simply burns more gas with no noticable performance increase and anything above the max rating is just plain dangerous."
 
"Okay, so I understand the boa

"Okay, so I understand the boat is underpowered, no doubt. The boat is rated for a max of 75.
Regardless, the current motor we have still does <font size=""+1"">NOT RUN!!!</font> We have even bought a DVA meter to further check the ignition/electrical system. Those four checks came back good. I really want to fish sometime this year. Can anybody out there in Marineengine land help us???

The following are the numbers we have as of now.

Motor specs
1996 Mercury 25 Horse 2 stroke (classic I believe)
Serial number 0G288618.

Checking for ohms,
Stator -
Red/Black measured 141 ohms (spec at 100-180)
Blue/Black measured 31 ohms (spec at 29-35)
Red/Blue measured 30 ohms (spec at 28-34)

Trigger - (Brwn/Wht)/(Brwn/Ylw) 7.62 ohms (spec at 6.5 - 8.5)

Coils - (positive disconnected)
Upper -
Across terminals .3
Boot to terminal .938
Lower -
Across terminals .3
Boot to terminal .933

Cylinder 1 (Top)
Across terminals w/ DVA - 180 (spec'd at 160 - 250)
Cylinder 2 (Bottom)
Across terminals w/ DVA - 200 (spec'd at 160 - 250)

Stator (Low Speed) 320 (spec'd at 220 - 320)
Stator (High Speed) 60 (spec'd at 30 - 220)
Switch Box Stop Circuit 320 (spec'd at 220 - 320)
(backprobed)

All figures were with motor cranking via starter."
 
Your cranking numbers look fin

Your cranking numbers look fine. Have you put a timing light on the plug wires to make sure the power is actually transferring to the plugs?
 
"We will most definitely be tr

"We will most definitely be trying that. More than likely either today or tomorrow. Any other ideas past that? Could the motor be out of time? Is that even likely, seeing as how we only pulled the flywheel to replace the stator. Since this motor did die on us, it has not so much as even coughed or sputtered. Just cranks and cranks. Wet plugs though, plenty of fuel. Could it be a fuel problem? Could a clogged carb cause this even though the plugs are getting fuel?"
 
"Have you tried simply putting

"Have you tried simply putting in a pair of new plugs - it sounds simple, but I have seen that many a time where a fresh set cures all the ailments...

For 5 bucks or so, it's worth a try.."
 
"I feel your pain, I am going

"I feel your pain, I am going thru almost the exact same issue with a 97, 25 HP motor. Only I haven't checked fuses, trying to locate them, but your problem is mine. Maybe someone will come up with a solution."
 
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