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96 Bayliner 30 mercruiser loss of power high RPMbs

G

gsong

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"96 bayliner Starts up great,i

"96 bayliner Starts up great,idles fine Ran great last summer. The problem started off slowly and was no big deal. It powers up in open water and after about ten or fifteen minutes boggs down and no power. It used to happen every other day now it is happening every time I take it out. Had the carb rebuilt installed water seperator, new filters, cap and roter, plugs, dumped fuel and went through every wire. I did notice today that the oil on the dip stick shows it's way over the top mark maybe even up to a quart. The temp gauge is on zero it's either broken or the thermostat is stuck open it's not getting hot at all. I'm going to put a new gauge in today to see what's with that. Any ideas?"
 
"I did notice today that t

"I did notice today that the oil on the dip stick shows it's way over the top mark maybe even up to a quart."

Engine sounds like it may be hydro locking and water is getting in the oil pan. Open the oil drain a little to see if water runs out. If you get water then check the exhaust mans and riser/elbows for leaks. Also the exhaust shutters for proper operation.

"The temp gauge is on zero..."

Ground the sender wire to see if the gauge pegs to the hot side. If it does then the temp. sender is the problem.
 
"Thank you very much, I will c

"Thank you very much, I will check it out tonight. I was going to try to drain some of the oil off, it was serviced by a reputable outfit so I didn't think much about it."
 
"it was serviced by a repu

"it was serviced by a reputable outfit so I didn't think much about it."

They may have accidentally over filled it which could affect it.
 
"Well, back to square one! I p

"Well, back to square one! I pulled almost a quart of oil from the pan no sign of water. Got it to where it should be on the stick. Replaced the temp gauge and it worked fine it maintained about 140 after warming up. I took it out and ran at 4000 rpm's for about a minute until it bogged down. Once I threw it into neutral and waited a few seconds I could get going again but under 2000. It never dies it just lacks power. What about coil? I had an chevy that used to do kind of the same thing. Gee, I'm frustrated!"
 
"Could be starving for fuel to

"Could be starving for fuel too. Check that the fuel tank vent line is not obstructed/kinked.
Try opening the fuel fill cap while running - if it improves it's the vent line. Also check the anti-siphon valve in the tank - part of the fitting on the tank where the fuel line connects.
Run it on a separate portable tank to bypass the valve. Also check fuel pressure and volume from the fuel pump, and the diaphram if it's a mechanical pump. And maybe a vacuum leak somewhere in the fuel system/carb."
 
"Went out today, Checked the w

"Went out today, Checked the wiring as in diagram all clean looked great checked for frayed wires all looked good. Changed filters again, old ones were clean as could be. Pulled the anti-siphon valve, clean and operating just fine. Sprayed berrymans around the carb no leaks. Pulled the cover of took off the spark arrester fired it up and headed out. opened the fuel cap, and ran at about 2000 rpm's about two minutes before it started cutting out. This time it was worse than ever, it actually died on me when I tried to power down that hasn't done that before. Put it all back together and I limped it back to the dock had to add more rpm's to get it going and came in pretty fast. It seemed fine until it got to operating temp, the gauge never gets to 150 and is steady. The only thing I haven't done is try to by pass the tank because I was alone and need somebody to hang on the the tank for me. It is getting progressively worse when it started last season I could live with it, now I'm afraid to take it out and getting stuck where ever the wind takes me. Can a coil cause these symptoms?"
 
A dying coil can cause all typ

A dying coil can cause all types of confusing symptoms. One most prominent is a loss of power and cutting out. Some will restart right away while others will require time to cool off.
 
"A good coil can be tested w/a

"A good coil can be tested w/an ohmmeter.

Primary side + term. to ground = 1.1 to 1.5 ohms.

Secondary side coil output to - term. = 9,500 to 15,000 ohms.

When the engine dies, turn off ign. switch, remove the elec. wires and ground the coil output wire to discharge any leftover spark before measuring resistance from the coil output to the neg. coil terminal."
 
Tonight I pulled a plug to see

Tonight I pulled a plug to see what kind of spark I was getting and it looked kind of orange not real strong. I thought I'd take it for another spin and see what my spark looked like when it did it's thing. I'm really confused now because I ran it at 3000 to 3800 for about a half hour and it bogged down only once. I throttled down and it recovered pretty quickly. Totally opposite of what it did today. Little rough idle back to the dock but nothing like earlier. I'm going to go down to my local boat shop tomorrow and see if I can pick up a coil. If it doesn't cost an arm and a leg at least I can rule that out.
 
"Well, I give up! New spark co

"Well, I give up! New spark coil...no change. Pulled top off carb clean as could be. Sprayed out the jets everything looks great. I pulled the dist. cap off cleaned the wires and pulled the module out it was a little hot wires looked fine. I just don't have a clue any more but I have to rule out fuel. Something happens when it reach's operating temp and when the outside temp is also warmer. The only good news was I found a coil that just happened to be on the shelf someone returned as wrong part and I got it for $80.00 instead of the listed $125.00 Other than than I need to see a boat shrink!"
 
"Guy,I went through the wiring

"Guy,I went through the wiring again tonight. Payed special attention to #6 and #4 cleaned em real good sprayed em with contact cleaner. I did notice on wire coming from the Spark coil a single black wire has been apparently spliced into a green white wire but other than than everything seemed okay. I pulled the plugs tonight and tested compression and got 180 on all four cylinders. Even replace a vent hose that had some holes in it and it wasn't even in the engine compartment all the way anyway, aimed the other at the distributor. Took it out ran at 3000 rpm for quite a while and kicked it up to 4000 and it did fine for about a minute... then she bogged down. Once it boggs down it starts getting sluggish at just about any rpm after that. I was going bypass the water filter while out there but thunder storm was approaching so I took it back in. I'm at a loss?"
 
"Guy, one last question before

"Guy, one last question before I take this thing out in lake and scuttle it. The coil in the dist. looks a little brown/yellow with gluey looking stuff on it, maybe like it has gotten hot maybe a little melting? I don't know what a new one looks like so I don't know if that could be an issue. I would honor your opinion. Thanks"
 
"Gary:

There are three igni

"Gary:

There are three ignition parts known to fail: the high voltage coil, the dist. pick up coil and the dist. module. You have inspected each one carefully and each appears normal except the comments about the HV coil.

There is a cold test you can perform on the pick up coil and module. Get a can of electronic circuit chiller in a can from an electronic shop. Drive the boat until it falters. Open the dist. cap and spray the module long enough to chill it. Reassemble the dist. and see if it will run normally. If it does then replace the module. If it won't start, remove the cap and spray the pickup coil long enough to chill it. If it runs replace the pick up coil. Last test is the HV coil. Perform the same chilling. If there is moisture from the chilling spray it off w/WD-40.

My bet is the module is on its last electron."
 
"Guy, it took me a while to ge

"Guy, it took me a while to get back out and work on the boat, I did the freeze test on the module and coil and didn't seem to determine anything. Today I went out and one more time pulled the anti-siphon valve to it to my boat dealer and they said it looked just fine. One guy suggested knocking the ball and spring out and try it to see if it made a diff. I also pulled the HARNESS ASSEMBLY, Distributor Module to Ignition Coil totally off and peeled back the harness and found what looks like a diode on the purple wire. I went back out left the cover off the wires and separated them, put the asv back in but before I did I tried to knock the ball and spring out but only got it part way so it rattled around when I shook it. Fired it up and ran at over 4000rpm's for a half hour never ran better. So I shut it down and put the wire harness cover back on the coil wires. Took off and in about five minutes started to bog down again. Took the harness off and flew back to the dock at 4000rpm's no problem. I'm assuming the wires are either getting hot or feed back into each other? I looked on the parts list and it shows the wiring harness no longer available. That has got to be the culprit. You were right all along I checked all that stuff out but never pulled the jacket off. Thank you so much I guess now I just need to find a new wire ass. or keep them separated somehow? YOU BE THE MAN!"
 
"Yes that is the part number I

"Yes that is the part number I will certainly do that. Thanks again for all your help. I have talked to at least a dozen boat mechanics and they weren't even close, thank you so much!
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"Gary, did you notice if your

"Gary, did you notice if your tachometer would bounce up and down when power loss occurred? I'm having a similar problem and have tried similar steps as you and still having issues."
 
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