Trouble starting 496 Mag
 

Hello all. Newbie here, with a few questions.

I just purchased a new to me, 01 Baja 272 w/40 hrs on a 496mag. I took the boat out for the first time today, and ran into trouble. The boat fired up on first try, and ran smooth at idle for about 10 min. When I backed away from the docks, it began to stutter/miss as if it were running out of fuel. I assumed my fuel gauge was faulty (reading 1/4-3/8 tank) and refueled the boat. Once back at the lake, the engine still would not start, and I nearly drained my battery trying.

Is there something I'm missing? Perhaps a fuel shut off valve? Air in my fuel system? Or something else all together?

What is the standard manufacturers warranty for Baja/Mercruiser? Is my boat covered?

I appreciate any input/adivce you all may have to offer.

Joe

Since you just purchased the boat, did you buy it from an individual or dealer? Dealer-warranty? Individual-call and ask about previous issues? Wish I could help further. Stick around and you'll get some good advice here on this board.

Welcome aboard and check out the Baja section!

The Merc standard warranty is 1 year, but can be extended to 5 years(more $$). If you bought it private, did you receive any extended warranty paperwork? Otherwise, it's probably out of the warranty period.

Anyway, have you replaced the fuel filter. Maybe some bad gas in there or a gummed up filter. Can you hear the fuel pump running when you turn the key from 'off' to 'run'(not start, just run)? Could be a bad pump.

Thanks for the quick replies.

I bought the boat from an out of state dealer. No indication of warranty extended or otherwise. Other than them assuring me the boat was in great shape/working condition.

I have not replaced the fuel filter. But will do so ASAP if that's the culprit. I can hear the fuel pump each time I turn the key. Is there anything else which could be causing this problem?

1. Fuel filter is the most probable item especially if it sat during the winter with little or no fuel which would result in heavy water build up.
2. If you boat has one, the fuel shut-off at the tank (most boats do not have them since the CG does not require them anymore).
3. Replace all gas with fresh.

There really isn't much more to break so if that doesn't work then get a Merc mechanic to run a diagnostic.

when engine running @ dock would it rev in neutral?
sorry for this basic one but was your kill switch in place after stalling?

Formulafastech: The engine would not even try to fire after it died the first time. I have not checked for spark yet.

Vyper340: I just picked up a new fuel filter, and I'm headed out to install it now.

28SS: Nothing is too basic for me right now. LOL
The engine would rev in neutral, and the kill switch was in place.

It seems the problem will be harder to diagnose than I had hoped. Before installing the new fuel filter, I tried starting the boat just to see what would happen. The boat started instantly. It continued to run smooth for approx. 10 minutes. It then began to run as if it were starving for fuel, backfired, and quit. The boat would not restart after this. I installed the new fuel filter, and tried again. Nothing.

I gave the engine 3 hours to cool, on a hunch that it would start again. It did, ran for 10 min, then same story.

My theory is that after 10 minutes or running (open loop), the boat begins to reach operating temperature (140-150 degrees) and then the computer (closed loop) is shutting the engine down.

Does this sound right? Perhaps a faulty sensor/sender? Has anyone here had this problem with a 496 mag before?

I don't see what alternative I have, besides taking the boat in and having it scanned for codes. Hopefully somone here will have another solution.

01 272 boss,

I did a search on the bleow site for any service bulletins that describe your problem. Unfortunetly, nothing was listed that fit your explaination of your trouble. But, here is the link for the site anyway. You or others may find it useful for something someday.

http://www.bravodrives.com/bulletins_main.html

checkmate454mag: I appreciate your effort. I'll check it out, maybe I can learn something.

I don't know if this information will help solve the problem, but I learned a few more things tonight.

I was going through the boat, checking fuses, tightening loose bolts, etc. I found one blown fuse in the engine compartment, and decide to try starting it again.

It had been nearly 5 hours since the last time I started it, so I knew it was cool. The engine fired right up, but quit in less than 3 minutes this time, at approx 120 degrees. Since I was watching my gauges the whole time, I noticed that when it began to stall, my tach quit working. Correct me if I'm wrong, but this should indicate that there is no spark.