91 Force 150 Missing, won't turn up! Help!

[Timbersnake]

Well...I let my boat sit for almost 2 years...Ran fine before putting up. Would turn 5200rpm at WOT. Now, engine idles fine (maybe a little rough, but is always that way) but doesn't have the power it used to. Going to full thottle from idle the engine will rev to about 3000 and then, after getting up on step will rev to about 4000 (coughing the whole way). It barely gets on step, and would not pull a skier. This boat used to JUMP out of the water and onto step. When running at 4000, the engine will intermittently and instantly rev to 4500, back to 4000, up to 5000, etc., etc., etc. I bought new plugs and cleaned em a thousand times. (thought the fogging agent I had put in the engine was causing plugs to foul) The RPM transitions happen so fast that I can't imagine it being fuel related, more like a short somewhere.<br />Took it to my local dealer, (and yes, my a$$ is killing me) where they checked the coils (good), the compression (excellent x 5), and other electrical goodies. Everything (they said) checked out fine in the shop. So...they decided it was running lean, and turned all 3 mixture screws out from about 1 turn to 3 turns, told me it was just running lean, and that they had fixed it. Well, I took it out, ran it, and except for running VERY rich, it was the same.<br />Let's recap. The engine idles. Doesn't have power it used to. Has great compression. New, clean plugs. (interesting note...the #2 plug is often much 'cleaner' looking than the others..although a buddy of mine was silly enough to touch the wire while the engine was running and it shocked the **** out of him.) It misses at high speed, and sometimes instantly stops missing and reaches its normal RPM...but never for very long. The shop guys are telling me that things check out on the bench. Any ideas? Thanks a ton for your help...it's summer!!!!! I gotta run this boat!<br />Tracy

 

[Bry21317]

Re: 91 Force 150 Missing, won't turn up! Help!

Timbersnake,<br />What I would try doing is replacing the caps that came on the spark plug wires. I got some NGK ones from a motorcycle dealership that screw on. It sounds that since the one wire shocked your buddy, there is a break in the insulation somwhere. If it is the same as the Force 125 HP engines, this should do the trick to help you at least somewhat. Also check to make sure there are no breaks or cracks in the wires. You might also want to keep them coated with some silicone spray to help keep them from breaking and cracking.<br /><br />Also here is another post I made about my Force 125 HP, that I did that basically really brought it back to life, you might want to try some of the things. It is at: http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=17;t=013682 <br /><br />Thanks,<br />Bryan Cox