2001 Mercury 25HP Outboard Problem - HELP

I have an extremely frustrating problem with a 25 horsepower Mercury Classic outboard (400cc two cylinder two stroke) that is currently pushing my 2001 Craig Cat. <br /><br />I bought the boat used, and it had sat for a year or so without use. The first time I took it out, it didn’t run badly, seemed to hit on both cylinders and only missed occasionally. It was then flushed and stored for about three months. When I took it out this time, it ran very rough and only seemed to be going about half speed. My guess was that it was only running on one cylinder. The plugs were a little wet and black, not the nice gray that you are supposed to see. <br /><br />I bought two new spark plugs, and for good measure, pulled the carb off, removed everything from the carb (jets, floats, etc), cleaned it all with carb cleaner, blew everything out with compressed air, and put it back together.<br /><br />I primed it up and tried to start it, didn’t want to fire. I primed it a few times, choked, etc. After about 10 minutes I could get it to sputter. Put in a little starter fluid, would start and run for a second, but will not run under its own power and idle. You could prime it, it would start and run for about 5 seconds, then die again. If you could get it to start, and hit the prime, it would pick up RPM, but would then die again. Seems like the carb will not fuel itself properly. You could keep it running semi-steadily if you hit the prime about a second before it tried to die. <br /><br />Then came the seriously bad part. I thought if I just hit the prime button a few extra times I could get a little more rpm and it would suck out whatever was going on. Wrong. The rpm jumped to full and just sat there absolutely wailing away. I turned off the key and it didn’t quit. Yanked the plug wires, didn’t quit. I finally pulled the fuel connect off and about 5 seconds later it quit. It seemed that the engine was dieseling, but at full RPM. NOTE – while this full rpm dieseling condition was going on, the carb butterfly was NOT open. Somehow it was getting air, or was otherwise able to pull full rpm but not through the carb butterfly. <br /><br />I cleaned my underwear, put the plug wires back on and tried to fire it, no action. As with above, it would fire if you primed it, but quickly die. Again, if you primed it a few times, the huge rpm situation described above would surface (I endured it several times before giving up). <br /><br />Because it seems that things only went seriously haywire after the carb cleaning, it would necessarily follow that something went amiss with my cleaning job. <br /><br />Relevant notes from the carb cleaning: <br /><br />1. this engine was equipped with a cumbersome prime system that made removing the carb quite difficult. I removed the entire prime system, if you want to prime it now, you just have to reach your hand back and hit the little prime button, not a major inconvenience. The prime did not appear to attach to the throttle arm system in any way, and from what I could see, did not appear to otherwise affect the functioning of the carb. I also removed the fuel filter system which ran upward from the remote tank, to a little shot glass size filter, then to the carb. I simply put a line from the line that fed the filter to start with, and connected that line directly to the carb. <br /><br />2. When I pulled the carb apart, like a bozo I did not pay close enough attention to which way the float came out (there is a slight difference on the carb). I also did not pay close enough attention to whether or not there was a small spring under the float arm that controls whatever jet or valve is under the float arm (I do not think there was one, however). I did, however, between one of the huge rpm rounds described above, yank the carb and turn the float over, no difference, still wouldn’t run without being primed, and suffered another huge rpm experience. It was then that I gave up and though it best to ask someone before the engine came apart. <br /><br />Something is telling me that pulling off the prime apparitus and one of the linkages that connects to just below the stator might be causing this. Does anyone have any close-up pictures of this engine from the right side that they could take and send? Does anyone have any thoughts on this? Any help would be appreciated!!!

Re: 2001 Mercury 25HP Outboard Problem - HELP

Also with regard to the above, does anyone know who makes the carburator for it, and where you can get a carb rebuild kit? I looked at the carb, best guess is that "WMK" makes it, but hard to tell that, and hard to tell what the model number is.

Re: 2001 Mercury 25HP Outboard Problem - HELP

Without sounding like a "rubya the wrong way guy"..dija consider buying a manual? The shift throttle, and carb linkages on that motor are very sophisticated and work very well unless they are "tinkered" with. The Merc 20-25 HP is one of the best motors on the market in this class. I owned on of these for awhile an it was very reliable and a well built outboard.<br /> Mercury online has all the parts you need and they are reasonable for that motor. There are exploded views and part numbers with prices at the following site. You need your serial number and go to: http://www.mercurypartsexpress.com/PartsExpress/ProductSelection/ServiceParts/sphome.asp?CID=

Re: 2001 Mercury 25HP Outboard Problem - HELP

hey b.k.s i have an 2003 15 hp. with dam near the same carb setup E- mail me with ph# and I,ll call you and we can compare notes internet is to slow and most replies or from smart ***,s anyway.

Re: 2001 Mercury 25HP Outboard Problem - HELP

FishFryMan:<br /><br />Your e-mail is not listed. E-mail me at smckay@mckay-law.com or call me at 941.737.3922 when you get a chance, I'd like to discuss this and see if I can get back on the right track! Thanks!