Posted by dgr7 on 08/13/07 - 10:02 AM
#1
hello,
I'm hoping someone on this discussion board can help me with my boat problems before I have to put it back in the shop for repair. I don't know a great deal about boat repair so please keep that in mind as you read. I have a 1999 BW Dauntless 13" & 1999 50HP 4stroke Mercury
engine
Here's what's occuring:
I just got it out of the repair shop a few weeks ago. The boat before that time had been sitting
dorman & unused since Spring 2003. The repair shop did the following to the boat:
"found carburators were in bad condition and water pump needed replacing. compression was 125 psi on cylinderws 1,2 and 4 #3 was 75 psi due to old fuel and possible sticking rings. removed and replaced water pump and removed and went thru carburators, set and adjusted linkage and river tested OK"
They said and documented that it was running Great with no issues when they gave the boat back to me. On the Water Test Evaluation sheet, it said how the engine ran at various stages of RPM while they were out in the water testing their repairs....6150 was the higest RPM setting they said occured. The same sheet also says there was no abnormal vibration noted during run and the boat responded to shifting normally.
Just yesterday I put the boat in the water at a local boat landing for the first time since getting it
repairs. The fuel line had been disconnected ever since getting out of the shop. I connected it.
I had filled the tank full of gas on the way to the landing. I then proceeded to crank the engine.
Nothing, no reaction at all! I then remembered how my Dad (the previous owner of the boat before
he passed away) had said that a fuse in the motor blew often and I had some spare fuses with me.
Sure enought, I took off the motor lid and found the blown fuse. Replace it with a good one, put the
engine back together, choked the engine, primed the fuel line bulb many times to get it firm, then
Voila! the engine cranked! The stream of water was coming out of the back of the motor to let me
know that it was flowing through the engine well.
Now here's where the problem is that I'm stuck on and am making this forum posting about. The
engie would sit there running in a Neutral position just fine and not stall out at all. As soon as I
pushed forward on the accelerator, the engine "shuttered" and "sputtered" and basically nothing
happened, the propeller won't turn, it seemed like the engine was Stuck in Neutral. I also tried going
in reverse. I had a small amount of luck with that, in that the boat would move backwards at a snails
pace, almost barely noticeable, and other than that the boat wouldn't move at all forwards or
backwards. I went through the whole process of turning the engine off, looking at all the engine
cabling, cranking the engine, it would sit in Idle fine, then when I try to go forward or reverse at any
speed nothing would happen other than the "shuttering and sputtering" and occasionally I would
stall it out. Also while trying all of this I managed to blow another fuse, but luckily I had many spares.
Basically I'm at a loss as to why the engine's not working. It worked Great back in 2000 - 2003 and
the repair shop said they had it running Excellent and it's a reputable place and I have no reason to
believe what they told me wasn't true.
So what do I do not to get the engine to run properly and actually move the boat forward and
backward properly?!
I had a thought about the spark plug needing replacing, they don't mention anything about the spark plug on the repair sheets, so I guess it's old....would that possible be it?
thanks in advance,
david
Posted by joninnj on 08/14/07 - 4:08 AM
#3
Hi Drg7,
Welcome to the forum, great source of info, I am also a new member. I'll take a crack at this although I do not have experience with a four strokes.... Few things from your post. 1st, The fuse.. In 35+ years of boating with outboards I have never blown a fuse. If this is regular occurrence then there is another problem.
2nd, [color=red]
Big red flag with the low compression.[/color] Since you have 4 cyl engine it may seem to run normal in neutral, but shift into gear and add a load to the engine... it will die unless you jamb the throttle down... may not be the best idea :o
In reverse the gearing is different, may creating a lighter load on the engine.
Very hard to test an outboard when only will run a reverse.
I would bring this back to the mechanic /dealer and insist it is not right. If possible show them. Also find out what was done for the low compression... This may be as simple fix, like a head gasket...or run some decarb product through it like ring free or seafoam at a high concentration. I do not think a sticky ring could cause that big a difference in compression, but I am not sure. I am sure that bad gas will definitely not do it...
Regardless, it will never run right with low compression on one cyl. "Rule of thumb" on this, a reading should not differ more than 10% meaning with a reading of 125 lbs, a cyl should not be less than 113 lbs. Even with that difference I would suspect.
BTW if it does turn out to be a bad spark plug, never go back to that dealer...:|
Hope this helps
Edited by joninnj on 08/14/07 - 4:20 AM