Not being mechanically inclined, I'd love input on an issue with my engine before I wind up being at the mercy of the mechanic: <BR> <BR>Sanger V215 <BR>Merc Black Scorpion <BR> <BR>Problem is engine is "missing" intermittently, but frequently. It only happens under load - if engine is run disengaged from tranny, it's fine. Pulling up a rider during acceleration and while cruising with rider behind, I can feel/hear frequent "misses". Each time the rpm dips about 100 with the sound. <BR> <BR>Boat has 300 hours, have had regular services and oil changes/filter changes. Gas is only about 2 months old, and boat has been run every three weeks or so through winter. <BR> <BR>Have never changed distributor cap, not sure about spark plugs - have had a friend propose that as a possible issue. <BR> <BR>Thanks for the help!

i would start with a new cap and rotor and wires and plugs. a new fuel filter also. sounds like u might have water in the fuel tank. im not sayin u dunked the boat and have a ton of water in the fuel tank. maybe condensation got some water in there. take the fuel filter off and pour it into a glass mason jar. u might see it more water in it then u think. but i would start with new cap and rotor. if u got 300 hours and they are original im sure it looks ugly

Give it a tune up like rodney advised. Add a bottle of dry gas to the tank and some fuel treatment carb/injector cleaner. Check the timing. Make sure all vacuum lines especially the one going to the distributer have no cracks or plugged. <BR>What year is the engine? <BR>EFI? or Carbed?

Dave, will trade pulls for mechanical work! lol. Just let me know if you want help with it. Thanks again for the pulls.

Rodney - thanks for the tips - if there was water in the tank, wouldn't I hear the misses or pops when I'm revving with the tranny disengaged? We had it up to 3K RPM and she purred no problem, but under load it was a different story. <BR> <BR>Matt: EFI, engine has 300 hours, should be an 07 engine as it was new with the boat. <BR> <BR>Sparky - I may take you up on it! lol I am always looking to learn how to take care of the things I own, but engines have always been a bit intimidating! <BR> <BR>Thanks for you input so far! <BR> <BR>(Message edited by evadehickman on January 24, 2010)

Definitely start with the dist cap, rotor, plugs and plug wires. This sounds like a text book ignition miss. Once the hammer is dropped and the engine is under heavy load, the combustion chamber resistance increases which adds to the stress on the ignition system. Knowing that electricity takes the path of least resistance, the spark with find a weak spot in the cap, rotor, wires, plug wire boots, or a crack in the actual plug's ceramic, and arc to ground, and that's the miss you feel.

Mines done it from new. 760hrs on it now and it still does it once a set or so. More often if really heavily loaded. Have changed cap, plugs, wires, ECM, fuel filter no joy. Now I just put it down to "character", the engine is super strong and smooth so I can live with a miss every now and then.

This is more than just a minor intermittant miss with this engine. When an engine misfires there is a cause and a reason. If its bad enough an ignition miss can do damage to engine "hard" parts and should be resolved promptly. Darren, have you ever pulled the distibutor and had it run/checked on a distributor machine? That would be my next move with yours.

Oh, I said set but I mean session, ie every 6-8 sets or 20 or so starts, only coming out of the hole under maximum load and its one miss not a bunch. <BR> <BR>No I haven't done that, I'll look into it, Ta. <BR> <BR>(Message edited by ralph on January 24, 2010)

post serial number <BR> <BR>they had problems with fuel pumps

J.I.T.: <BR> <BR>serial # = 0W695343

Doesnt present itself as a fuel delivery issue to me from what I gathered after being on the boat yesterday but almost anythings possible...

OK <BR> <BR>no bad pumps that year <BR> <BR>i would look at dizzy cap and rotor, change plugs and fuel filters <BR>your going to need to plug it into a computer and do some lake pulls with it <BR> <BR>im based out of walnut creek and have all the computer programs <BR> <BR>I'm master certified on this motor also!!!

JIT <BR>Thanks for the input - I have zero DIY experience with boat motors, so was planning on having the mercrusier certified mechanic at my harbor do it. <BR> <BR>I am really interesting in learning, though - are the things you mentioned generally simple to learn? I am mechanically able, but have no experience. <BR> <BR>As far as the computer hook-up, how would I go about that? <BR> <BR>Sparky - thanks for hanging in there on this thread, too. I'm a little nervous about the cost I might face. I read up in my engine service guide and they definitely recommend distributor/plugs/wires at 300 hours. I'll try to get on the phone with the Bethel Harbor mechanic this week to discuss. <BR> <BR> <BR> <BR>Thanks for the info...greatly appreciated! <BR> <BR>(Message edited by evadehickman on January 24, 2010)

best advice is get a service manual <BR> <BR>i have them all so you can email me <BR> <BR>i can work on the boat <BR> <BR>more certified then most shops around here!! <BR> <BR>i go to merc training 2 times a year in LA!!

No problem Dave. We can do all of the work for much less than you will pay to have it done. I can get the parts at cost as well through the shop if you dont have that kind of hook-up. Just let me know.

they had problems with dizzy, but according to merc the EST on black scorpions have no problems

Mine has done the same thing for the past 300 hours. Mine has a miss when you stab the throttle from an idle. If you roll into the throttle its fine. I've replaced the IAC, Filter, Plugs, Cap/Rotor. I also check the fuel pressure which showed normal. Any ideas? The service center i've used in the past said its a common problem with the BS motor?

It is due for a service and I will agree with Just-in-time that the plugs should be changed along with the fuel filter. The cap and rotor is a good idea too. Plug wires should only be changed if the problem is not resolved and they can be tested using an ohm meter. Plus a careful inspection of the wires anywhere they rub against something metallic should help determine if they are failing. Any rust on the end terminals of the wires means time for replacement. <BR> <BR>Take a close look at the plugs for any kind of abnormality from one cylinder to the other. Note which cylinder it is and check the plug wire. Then look inside the cap for any carbon tracking off that cylinder. <BR> <BR>Plugs are easy to change and other than checking the gap, needing a spark plug socket, ratchet, and extension, do not require anything out of the ordinary to change.

Nate (norcalmalibu) <BR> <BR>what is the serial number?

This may be of no help, but I had what sounds like the same issue on my last outing last year. I had put the boat away wet in a rain storm and didn't have access to dry it out. Therefore it sat about 3-4 weeks that way right before i had the issues. Thought that might have something to do with it. <BR> <BR>I didn't get to diagnose it because it was getting put away for the season, but plugs, cap, rotor were my ideas. Interested to hear what your solution is.

My 07 Supeme V220 does the same thing. Same engine.

Problem is fixed! If you're interested, it was 100% the distributor cap and rotor. See pictures below. Many thanks to Sparky Jay who came out and did the work - I enjoyed learning very much. Cleaned flame arrestor, changed fuel filter (dumped contents into clear container and saw no water, eliminating that theory), changed cap and rotor and changed plugs. Plugs were in great shape, but the inside of the cap and the rotor were shot. Pictures show side by side new vs. old. (Chip in plastic of rotor came from having to pry it off with channel locks.) <BR> <BR>Thanks again, Sparky! <BR> <BR> <BR><img src="http://www.wakeworld.com/MB/Discus/messages/3183/772263.jpg" alt="Upload"> <BR><img src="http://www.wakeworld.com/MB/Discus/messages/3183/772264.jpg" alt="Upload"> <BR><img src="http://www.wakeworld.com/MB/Discus/messages/3183/772265.jpg" alt="Upload"> <BR><img src="http://www.wakeworld.com/MB/Discus/messages/3183/772266.jpg" alt="Upload">

Damn,that was bad! <BR> <BR>Yeah,Sparky can fix/build anything. <BR> <BR>How was the ridin?

Do you run in salt?

"How was the ridin?" Epic conditions, Mother Nature blessed us today out on the Dirty D. Dave, happy to help. Glad we got the issue resolved, first try. Thanks again for the pulls!

Damn... Cool pics.. Glad it was an easy fix.

Is the button in the center of the dist cap gone? Can't tell from the photo, but the rotor still shows a little wear from it.

that got hot!!!!!!!!!!!!!!!!!!!!!

Never ran in salt, button in old cap was still there but heavily corroded like the rest of what you see. <BR> <BR>Riding was awesome - no wind, no current, no other boats, sunshine all afternoon, absolute glass. There was a little bit of debris, but 98% tule stalks.

I hope to heck that is my issue on my black scorpion, since I have the exact same symptoms. Have to wait till spring though.

Todd - how many engine hours?

100 hours. 07 model year with one season on it. Ran flawlessly until the very last outing for the year. I had left it out in a rainstorm, actually had to trailer it home in the rain, so everything was wet before i put the cover on. It sat for several weeks like that, so that further leads me to think it's moisture/corrosion related. <BR> <BR>(Message edited by Antoddio on February 01, 2010)

David's issue is caused by moisture as you can tell. Do you guys prop up your motor cover when you store your boats? I kept a plastic container that was my dogs water bowl, bailing bucket for the Coast Guard, and happened to work real nifty for propping my motor box open about 5" so it could vent. Pulling the plug and getting as much water out of the bilge as possible helps too.

Good advice. Tough though when I have to leave the boat in the storage yard all the time. <BR> <BR>Where did you get all the parts for the repair?

Mercruiser ignition parts are available at any West Marine store. Give your local dealer a shot first, though.

Yea...i just have to mortgage the house to pay West Marine's markups LOL

sierra and Mallory make the parts for mercursier <BR> <BR>way way cheaper and as good!

Sparky got the parts from his local store; although he also mentioned that cheaper prices could be found online.