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Mercruiser 5.0L low on power? Oh, and leaks. Pics.-gctid374004

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  • Mercruiser 5.0L low on power? Oh, and leaks. Pics.-gctid374004


    So this is my first post here, unfortunately it had to start on a bad note...

    I bought a 2003 Bayliner 212 last month. I did test drive it, and was told there was bad gas keeping the rpm's low. I've since brought it out to the lake this past weekend and with new gas have the same problems, so I'm humbly asking for some more experienced knowledge of this matter:

    The specs:

    5.0L Mercruiser w/ 4 brl Chester Quadra-Jet 220HP

    18 pitch aluminum prop

    Alpha I outdrive

    I was told this engine is brand new. The previous owner had the impeller fail and overheat the original engine. I was also told the shop couldn't get the new engine to work properly with the Merc carb and had to install the Chester Quadra-Jet. The first time I took it out for a test drive the boat dealer said the bad gas was causing the low RPM and it would be fine with new gas. It would, with no problem, get to 3200 RPM and then start to "ping" (sounds like the feignt sound of sparking, not sure if it's knocking or rocker noise?). That's all the power it has, 3200 is WOT. That lands me at a GPS speed of 32 MPH.

    I drained the old gas, refilled with 91 Octane brand name gas, added seafoam but still have the exact same problem. It seems to have great torque and up to 3200 RPM the engine runs great. Oil pressure is 30-40 psi.

    Another problem is an oil leak. It just started this weekend and as you can see from the pictures, is bad enough to foul the transom. There is spattering near the carb shown in the picture, my best guess is that it's coming from the distributor area. The picture of the bilge is after the bilge plug was removed.

    Idle seems to be off as well, when cold or after idling a long time it will start to surge from 200 to 500 RPM and occasionally die. There's a very strong gas smell and white exhaust smoke telling me that maybe I'm running too rich? Or am I burning oil? The bilge fills with water/oil mixture within 6 hours if I don't pump it out.

    I've included some pictures to help visualize things.

    Really appreciate everyone's help and knowledge they're willing to share here.

  • #2
    The transom sooting isn't not caused by oil- its an overy rich mixture. Between the oil leak and the improper running, I'd be visiting the dealer to have them take care of the problems. Further, have them produce records for the "new engine".

    Thats' a new low for a dealer- "run 91 and you'll be able to go beyond 3200 rpm."


    • #3
      I would be suspicious of the new engine as well. I'm wondering if the PO overheated the engine to the point of damage, head gasket etc. Also, sounds like ignition is wonky. The bad gas thing is such a cop out as mentioned above. Those motors should run on anything.


      • #4
        Man, I feel so dumb for not looking into this further. Unfortunately this boat was sold on consignment via the dealer so they're not liable for anything. I'm scared now that what you guys are saying is the case where the overheating took place, but the rebuild never did. I'm having it looked at tomorrow by a mechanic who can tell me more about what a sucker I am. op-


        • #5
          I'm assuming you're having a competant marine mechanic look at the boat. Have him check to ensure the carb is the marinized version while he's looking at things.


          • #6
            Is it the Bayliner dealer on Boulder Hwy? They're really going down hill in a hurry. If they took you for the test drive and misrepresented facts, they DO have some liability. If nothing else, I'll start the bashing here on BOC. If it's that dealer, go talk to Bruce, the owner. Be prepared and play nice, but he can be very intimidating...
            Jeff & Tara (And Hobie too)
            Lake Havasu City, AZ
            Current: 2022 Sun Tracker Sport Fish 22 XP3 w/ Mercury 200
            2000 Bayliner 3388 Cummins 4bta 250s (SOLD 2020)
            2000 Bayliner 2858 MCM 7.4 MPI B3 (SOLD 2018)
            2007 Bayliner 305 MCM twin 350 Mag B3s (SOLD 2012)
            2008 Bayliner 289 MCM 350 Mag Sea Core B3 (SOLD 2009)
            And 13 others...
            In memory of Shadow (7-2-10,) and Ginger (5-11-21.)
            Best boat dogs ever! Rest in peace girls...


            • #7
              luxor1472 wrote:
              Man, I feel so dumb for not looking into this further. Unfortunately this boat was sold on consignment via the dealer so they're not liable for anything. I'm scared now that what you guys are saying is the case where the overheating took place, but the rebuild never did. I'm having it looked at tomorrow by a mechanic who can tell me more about what a sucker I am. op-
              "The beatings shall commence until morale improves :hammer"

              It's nothing that time and $$$ can't fix- at the same time, the dealer may be liable for misrepresentation. You'll want to consult a lawyer to explore your options.

              If you have to go in the and repair damage, upgrade to MPI.


              • #8
                So I did a little investigating on the carb based on the marinized comment above (very helpful, thanks!) and it actually was designed for GM vehicles in the mid 80's and not boat engines at all? (Rochester Quadra-Jet 17084239)

                It actually wasn't the bayliner dealer on boulder highway. I don't want to say who it was until I've figured this out further. They did say it was a new engine and now I just don't know. The only thing I do know is the wiring is horrible on this boat. Cut wires open-ended laying all over the place. Definately not a professional job, even if it is a new engine.

                The mechanic has gotten praise from a few of my friends and seems very knowledgable over the phone. Gerry's Marine Services. We'll see!

                I'll definately upgrade to the fuel injection if I have to go through heavy repairs, good to have some silver lining...

                Thanks for the help, I know how easy it is not to post anything, but I really apprecate it, even the small ideas have been great!!


                • #9
                  The Rochester Quadrajet, was designed for vehicles way before the 80s in fact it has been in use since about 1965 or so, and was very commonly used on all GM engines right up until throttle body fuel injection became common in the mid 80s, by that time it had been around about 30 years. And there is nothing wrong with a well set up Q-Jet, as long as it is in fact a marine unit and not an auto carb and it is set up right for marine use. I have a Q-jet on my old OMC 4.3 and it runs well and is very economical because of the small primary bores. Your WOT rpms are way too low, they should be at least 4200-4500 and if the boat was always that way, that could explain why the engine had to be replaced. You need to get a good mechanic to look at it. The whole ignition and fuel system should be gone through. I did this with my boat after trying to get it to run right and it made a huge difference (this was years back like 2004). It needed a carb rebuild and a new anti siphon valve.
                  88 Four Winns 200 Horizon 4.3 OMC
                  98 Jeep Grand Cherokee 4.0/Selectrac
                  07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

                  Long Island Sound Region


                  • #10
                    So the mechanic says the carb has been properly retrofitted for marine use and should be great for this engine. He says he suspects the engine is not running all cylinders possibly due to bad valve springs.

                    Was able to get the engine to 5k rpms without load hooked onto the muffs.

                    He won't be able to open it up until Thursday or Friday though. I really hope it's valve springs... I can live with that bill.


                    • #11
                      Sorry to hear of your problems. I hope he is going to do a compression test. That should help determine the condition of your engine.

                      Started boating 1955
                      Number of boats owned 32
                      3870 presently owned
                      Favorite boat. Toss up. 46' Chris Craft, 3870 Bayliner


                      • #12
                        If its the dealer I'm thinking of, I've heard some pretty bad things about them too. And yeah, that's the second time I've heard someone say boulder boats is going downhill. Nice looking boat btw. If you see some random guy wave from a 30 yr old bayliner out at Mead, its probably me lol.