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jrdodd.
Ok, something weird is happening with my boat. I have a Classis with the 2.5 efi 200 Merc. 06 Model yr. I have been running a 25 pitch tempest plus since I have owned the boat. I hit a stump that required the lower unit and prop to be built (the boat has never performed the same. The prop was not repaired correctly but still ran 69 to 72 but was sluggish out of the hole. I assume alot of that was the prop issue. Blades was bent and all three were differnt sizes. Boat ran 5800 -5900 rpm with max speed 74.7 GPS prior to accident with great hole shot. Ok heres waht going on. I boat a new temepst same prop. I ran the boat today and initially it was like a freaking rocket out of the hole and ran like a spotted ape. I hit 72 before I had to shut down because I ran out of room. Power was great everything seemed back to normal. Boat had full fuel tank and full livewells plus tackle and my big jumbo butt. After this run I shut the boat down visited with a buddy for about 30 min. I consequently emptied the live wells and added him to the boat to go fish some. I hit the throttel and the boat would not come out of the hole. It sound like it had no power. Finally something kicked in and he sat on the flippin deck and the boat planned out. after this the boat would only hit 5200 rpm and full throttle was 60.7 gps. We fished for a while and then tried to take off again. This time the boat got up on plane but was still sluggish. Not like earlier. By the way my buddy probably weights 200 maybe. So I know the livewell water weighted more than he did. Anyway any help is appreciated this is the first time I have experienced this. Could it be the octane gas used, should I change spark plugs. I am not sure what to do. But I ahve a tournament next weekend and it sure would suck to have to have my partners sit on the front deck to get the boat to take off. I did check all plug wire and everything was connected. Anyhow sorry for the long post but I am concerned. Thanks Jason
You might have a fouled plug. Pullem and checkem. Might even be a carb issue. Hard to say what might be wrong. Its not the octane in the gas.
Yeah, I thought about that. I will check that tomorrow. When it initially happens the motor was real sluggish. Like it wasnt running on all cyclinders then it got a big boost of power you could hear it kick in. Anyway, thanks for the help Phil.
There are two many things on an efi motor you cant check. If you have a good dealer let him save you time, there is test equipment Im sure you dont have at the house. By all means check what you can, but dont start takeing thing apart you dont know about.
If its only doing it on the hole shot, pull plugs in the prop. From your description it sounds like too it is only happening on hole shot. Pull a plug in the hub of the prop and let it rev some on the hole shot.
It is the hole shot. But I also lost about 10 mph on top end. That I had 40 minutes earlier. That is the part that concerns me. The only item I will check is the plugs after that. I will take it to my local shop.
Hopefully it is not a carb problem on an EFI motor. But in any case, the Sherlock Holmes in me would ask “what was changed?” And the only real answer is “the prop”. There is nothing a dealer could do to screw up a lower unit unless they somehow changed the gearcase significantly (for example going to a CLE type gearcase on a boat that cant reach into the upper 80s will likely slow it down). Or they could rebuild and use the wrong gears to change the ratio. But that is way unlikely. But the prop is a different issue. Once a blade is bent, curled, splayed, etc, getting it back is a trick, and a good prop shop would be the place to get this done. And once it is done it is likely it will never run as it did when it was new, because the prop shop will make all 3 blades match exactly with respect to pitch and cup, something most new props do not do out of the box for the most part. So once you tamper with the prop, most likely things will change for all time. If you use merc lab-finished props, they are very reproducible from prop to prop, but they cost more. Had a good friend (Bob Jacks) that ran a prop repair shop here in Birmingham, and he once showed me how a brand new out-of-the-box prop looks when set on his prop blocks. No two blades were exactly the same before he “did his thing” to them. I wouldnt say this is the case on all props, as we never tested _all_ props. But it happened often enough that I had him check anything I bought there so that we started off with a setup that could be reproduced if something happened to the prop and it required some work, as he could get it back exactly to where it was since we knew it matched the proper block exactly… I just re-read your post and probably most of the above does not apply since your performance loss was over a 30 minute period, not after changing props. One thought… you didnt take on any water you didnt know about??? Otherwise I would check the plugs although that seems way unlikely if it ran good, you shut it down, then when you cranked it back up it was running badly. If you idled around some before shutting it down, I could see perhaps fouling a plug, but it seems like a stretch. Optis dont like old plugs, but the old 2.5 EFIs didnt seem to care…Last edited by oldtimer57 on July 13th, 2008, 4:17 pm, edited 1 time in total.2008 Pantera Classic2014 Mercury Pro XS 200
3 YEARS AGO AT THE OI ,MY COUGAR DID THE EXACT THING AND THE MERC CREW CHANGED THE FOULED PLUGS AND IT WAS LIKE NEW!!! LINK TO PLUGS AT GOOD PRICE—-http://www.ngkwholesale.com/BAYOU BANDIT
OK! Get your tools and run close to the ramp. Run that thing straight flat out, then pull the safety switch. Immediately pull the throttle back, and then remove the plugs one at a time. If one is not firing, it will show. Then you can replace one or all at your choice. Otherwise we would have the DDT ran on the engine at a Mercury Dealership and see what the ECM shows as a fault. It could be simple plugs and if you have an inexpensive source, that would be a simple one. Though if not a DDT would show something else. BCB
Ok! Thanks for the input. Now the nonmechanical side of me asking a question. How can I tell if it is not firing or if a plug is fouled. I pulled the plugs this afternoon at the house and all looked decent except for two that had burnt accumalted oil on them and I mean chared. How much do plugs run for this engine roughly?
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