Need Help! 2003 Merc 150 Saltwater (carb) Power Loss

rgm77

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Engine: 2003 Mercury 150 Saltwater (carb model)<br /><br />Problem:<br /><br />Running at an efficient plane, in about 15ft or water) I had a tremendous powerloss, it felt like running upon mud, but that was not the case. The power never came back. While in gear, (idle speed) engine vibrates violently and even when floored, wont plane or generate power.<br /><br />I thought it may be a tank of bad gas, but routed the fuel through a spare can, but the problem continued, so its not the gas. Changed the plugs, no change. <br /><br />It feels to me like its running on only 3 cylinders, and after removing the new plugs after short runs, 3 of the plugs (cyl. 4,5, &6) are perfecly clean, like they havent fired at all..<br /><br />So, I guessed that it may be one of the voltage regulators and switched out one, no change, swap it with the other, idle seems to be a little better, but still no change in the water.<br /><br />Both batteries were in need of terminal cleaning, which I did, still no change.<br /><br />Could both voltage regs. have gone bad? Is there something that I might be missing? I'm am somewhat convinced that it is electrical.<br /><br />Any help would be greatly appriciated.<br /><br />Thanks.<br /><br />rgm77
 
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Re: Need Help! 2003 Merc 150 Saltwater (carb) Power Loss

Wow, That is perplexing. What is the firing order? Are all of the cylinders mention on the same circuit? Could be a half and falf thing. eg one coil works one does not. If both Regs were out shouldn't run at all, Unless I am missing something. A distinct possiblity. :D
 

rgm77

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Re: Need Help! 2003 Merc 150 Saltwater (carb) Power Loss

I'm assuming that the regulators are just somewhat messed up; if that can happen.. The condition of the spark plugs after running the engine convince me that it is a half and half thing, and I assume that they are on the same curcuit being that they include cylinders 4,5, and 6. <br /><br />I would like for it to be a coil, but there are six of them, and I cant imagine that 3 would go out simultainously. I think that it would at least gernerate some power on 4 or five cylinders...<br /><br />Thanks for the help..
 

rgm77

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Re: Need Help! 2003 Merc 150 Saltwater (carb) Power Loss

PROBLEM FIXED!!!<br /><br />It was two of the coil packs that were bad. Apparently, each coil pack is grounded from top to bottom, so when the number 4 pack's gound went out, it cut out each coil beneath it. When the bad packs were replaced, all was well.<br /><br />NOTE that the bad packs were still firing, their gound relays were bad, thus cancelling out the lower packs.<br /><br />I hope my suffering spare others with the same :cool: problem some greif.<br /><br />Via con Dios and safe sailing.
 
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