5.0 L bogs down when accelerate

[cruz'r]

2000 Maxum 2400 SCR 5.0L runs smooth on idle after replacement of new cap, rotor and all the spark plugs, but bogs down or engine dies when engage the gear and try to accelerate. I appreciate any advice to correct the problem.

[mmwjr]

When did it last run good in the water, this year or last?
Tuned it up this spring?

Check to make sure you did not mix up the firing order (wires on wrong cap terminals)
Did you replace the wires? If reusing old ones, one may have been damaged.

Other though is to remove fuel filter and pour it into a glass jar looking for water and or crud.

[cruz'r]

Mike, Thanks for quick response. Last run good in the water last September 2013, I tagged the wires as I remove them when I changed the cap and rotor, so firing order is fine. Set all the new spark plug gap to .045 and engine runs smooth on idle, it just dies when accelerate. Removed the fuel filter today and poured gas into clear jar and looks fine and no water or other contaminant.

[mmwjr]

What outdrive do you have, Alpha? Is it dieing as soon as you are shifting? If so it may be the shift interupt switch (lower shift cable). This switch kills the ignition while shifting to remove load on a the Alphas dog clutch. The lower cable goes bad and has too much drag allowing the switch to stay closed to long killing the engine.

If you have a Bravo then not the issue as it doen't have this switch.

[Phillbo]

Is it carbed or EFI?

[mmwjr]

5.0L should be carbed. L for 2 bbl, LX for 4 bbl.

[cruz'r]

Mike, Stern drive is Alpha 1 gen 2, and it has carburetor. Yes, engine is dying when shifting to gear. There is a red button by shift cable says CIRCUIT BREAKER PUSH TO RESET, this probably the shift interrupt switch you're talking about. I'm going to try to reset this and see if that will solve the problem. My next move is to change the anti-siphon valve on top of the tank. I'm not giving up yet, my last resort is take the boat to the shop, don't want to miss the good weather we're having lately. Thanks for all your help, I love this site.

[mmwjr]

No that RED button is the 50AMP circuit breaker. The shift interupt is on the shift plate that is mounted to the side of the Starboard elbow. Look for a small micr-switch in the valley of the Y shaped shift lever. The cable from here to the outdrive either needs adjustment or replacement. For the boats age the latter is common.

"engine is dying when shifting to gear" this is a clear sign that the interupt switch is staying engaged to long (bad cable or adjustment)

[pascavone]

throttle up with the shifter in neutral and see what happens. if ok, then:

Makes sure your prop is turning under the boat, next time you put it in gear. if ok then:

check for black smoke or gas smell of carburetor loading up of choke stuck. if ok then:

Flame retarder, or accelerator pump, if not water in the float bowl, or a sticking float needle valve.

run a by pass gas line from a can and see if its your fuel.

[cruz'r]

Mike, Thanks again for all your feedback/reply. Changed the anti-siphon, didn't solve the problem. Taking the boat tomorrow to the shop/marina for repair, in time for me going to California for a week, boat should be ready when I get back. I will post whatever repair done when I get the boat back.

[mmwjr]

You could temporally disconnect the shift interrupt switch to see if the problem goes away. If it does them bingo replace the lower cable.

How are the bellows? This may be time to replace it all, it is normal maintance.

[cruz'r]

My 2000 2400 SCR is still at marina for a week now, they've been very busy with other boats that came in before mine. Discussed with the head mechanic about the engine dies when throttle up with the shifter in gear or in neutral. Mechanic says, good possibility the carburetor is bad and failing and not the shift interrupt switch or cable, engine should not die when throttle up in neutral. I should find out more when they get a chance to look it up tomorrow, stay tuned...

[mmwjr]

Wasn't clear that it dies with the shifter in neutral, this would eliminate the shift interupt circuit.


FYI the phrase "bogs down" means looses power but not dieing. Just for future reference.

[ss3964spd]

Like Mike is getting at, describing the symptoms exactly is really the only way us internet troubleshooters can help diagnose a problem. If the engine stops running the moment the drive is put into gear it suggests the shift interrupt. If it stops running when you go to throttle up after it's already in gear it suggests something else. If it only bogs, but keeps running, when throttling up in gear, something else again. You get the idea.

The first question I have is if it ever ran correctly after the cap/rotor/wires were replaced. If the bogging symptoms showed up immediately after that work was done then, naturally, you'd want to focus efforts there.

If it did run correctly after the above mentioned work, and sometime later the new symptoms started, then yeah, it does sound like perhaps the accelerator pump in the carb needs to be replaced - but certainly not the whole carb. Could also be a timing issue but, unless you moved the distributor, the timing should still be close enough. Wouldn't hurt to check it first though, before replacing the carb. If there is a "pop" (backfire) associated (another symptom) when throttling up, I'd definitely have a look at the timing, and the new cap and rotor.

[cruz'r]

Mike, thank you for the information and correction, posting should be retitled "5.0 L DIES WHEN ACCELERATE". It runs very smoothly on idle after the cap/rotor/spark plugs were replaced, but dies when throttling up in gear or neutral. The distributor was not moved and no "pop" (backfire) associated with the symptoms. My boat should be next in line at the marina where I took the boat. I will update you guys, thanks for all the help...

[cruz'r]

Just got the word from the mechanic at marina right after my last post. They found out that carburetor is the problem, lots of corrosion inside and not giving the fuel the engine needs during acceleration. I was given an option whether to have the carburetor rebuilt and cleaned or replaced with brand new one, $900+ more for new one including labor. I chose to have new one installed, and while waiting for new carb to come in will be another week of boating time lost. Thanks again guys for all your reply/feedback. Happy boating...

[Phillbo]

It will be worth it once done...


BOAT-Break Out Another Thousand (or 900 in this case)

[markwin1]

Same problem recently and it was a sensor that went bad. $200.00...

[mmwjr]

At least it is early in the season and you are not missing out on prime boating time

[ezcurra]

Same thing with my 5.7L. Replaced carb with rebuilt one and runs like new. Happy camper!


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