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    Merc 350 sputters, dies, won't restart after heating up

    There's nothing "Chevy" about a thunderbolt ignition system. It's all mercruiser OP: you are on the right track with replacing the ignition sensor in the distributor, it's the most fragile component of the system. Make sure you get oem and ground to the same flywheel stud as the main battery...
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    4.3 merc Alternator change and boats won’t start

    Continually blowing a fuse/tripping a breaker means a direct short to ground on the main red (fused ) lead to the dash. Double check your battery connections, clean and tight. Also make sure the alternator connections are correct. Orange on the output leads directly to main battery connection on...
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    160 to 165 Mercruiser manifolds and backfiring

    No idea about the manifold. As far as runnability have you checked fuel pump pressure and vacuum at various load/rpm? Guessing by the ignition system swap the plugs, wires, cap, rotor, fuel filters, timing, etc was all done? I know they rarely fail but is the coil new?
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    2005 Mercruiser 5.0 thunderbolt V ignition has no sparks

    Mercruiser tried several different methods of grounding various components of the thunderbolt system over the years. One was using the distributor housing/sensor screw as a ground, still had issues. When you install your (hopefully) oem, fully potted three wire sensor be sure to run the ground...
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    2007 3.0 Rattling/Timing

    By the sounds of it the timing was too far advanced and there was detonation occurring at higher rpm. The process you describe for setting base timing is correct for the electronic ignition. Does the engine tag specify a timing spec and what did you set timing to?
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    2005 Mercruiser 5.0 thunderbolt V ignition has no sparks

    Interesting, never seen loctite remnants on the shaft nor have I ever heard of anyone applying it
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    5.0 Mercruiser Problems

    Dunno what the smoke is. Steam? Is there enough cooling water exiting the exhaust/idle relief ports? Could be oil smoke but I can't smell it. This thread is so long I forget the original issue. One possibility is you have a head gasket failure and the result is the (possible) steam In any case...
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    2007 3.0 Rattling/Timing

    Are you checking timing at idle on cylinder #1? Is the firing order correct?
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    2005 Mercruiser 5.0 thunderbolt V ignition has no sparks

    Is there by chance a nut fastened to the screw on the bottom of the distributor housing?
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    2005 Mercruiser 5.0 thunderbolt V ignition has no sparks

    Rotor is not loctited to the shaft, its just a press fit and is nasty for removal due to rust on the shaft from lack of routine tune up/maintenance. I use the hooked jaw of a suitable sized channel lock to pry the rotor off. Clean all rust and other gunk with emery cloth. New rotor slides on great
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    Exhaust bellows install Alpha one

    FWIW I use no lube or adhesive, simply clean both gimbal and bell housing flanges and install the bellows dry. Never had one come off, ymmv
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    Merc 350 sputters, dies, won't restart after heating up

    Cool But we're not talking automotive here. This is a boating forum page concerning marine engine issues/repair and responses should be focused accordingly
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    Mercruiser MC1 drive (Pre-alpha) Rebuild

    The ram piston looks to me to be unusable, however I've never rebuilt a trim ram. Too much trouble, time and cost of parts to make it worth my while. You may be able to still find aftermarket rams that match your current ones, maybe... If you decide to upgrade to newer style, eternal hose rams...
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    Mercruiser 140 Points to Delco EST results in low RPM at WOT

    Glad you got it figured out. To answer your question as to why the difference between base timing/total advance for different vintages of the 3.0L engine is mainly due to the deterioration of the GM casting. The 2.5/3.0L castings are from the 60's and AFAIK haven't been updated since. Millions...
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    4.3 Mercruiser strange intermittent noise

    I'm with Chris on this one, sounds like an intermittent pulley/component noise. Remove the belt, spin each pulley freely (that can be), check for wobble/loose/noise or anything not smooth. Can go as far as running the motor for a short period to see if the noise goes away.
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    Worth flame arrestor upgrade for Mercruiser engines?

    Regardless of what you do, if you buy a new/different flame arrestor make sure it fits properly over the carb and does not interfere with the motor cover/doghouse
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    Merc/GM 4.3 tops out at 4000 rpm

    Possible the wrong cam was installed, all 4.3 GM blocks are cast as GM, GM manufactured them. Reman means nothing (at this point) because any engine builder can put any level of quality parts in a GM 4.3 block, including a different cam Did you check/adjust valve lash on the new long block...
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    correct plugs and wires for points type distributor on 140 engine

    What kind of trouble/issues? As stated the resistor for the coil primary (+) is a resistor wire in the factory harness, no external resistor. If you are seeing battery voltage at the (+) side of the coil with key on engine not running or cranking there is a chance either the resistor wire has...
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    Bravo 3 lower unit blown seals and corrosion

    It's okay, fella. You don't have to believe me but I can see the seals in both caps you have in the posted pic. Right hand one is a bit clearer and shows the witness from the top edge of the threaded neck on the bottle. But again believe what you like. I'll chalk this one up to the difference...
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    Bravo 3 lower unit blown seals and corrosion

    I hope you're kidding But in the picture you posted its the black seal/gasket seated in the cap, it seals the cap to the top of the threaded neck on the bottle
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