Snobo4rder08

bought this boat a couple months ago from Texas 2004 outlaw 25 with 496ho that says 130 hours. Something is wrong with the boat I bought. Motor doesn't sound right, almost sounds like gravel in the engine. Took it out today and ran it hard for about 15seconds and slowed down and then when I went to take off again boat shut off and I had to limp it back to home with least amount of throttle otherwise boat would shut off again. Opened up engine bay and smelled hot and coolant was at top of reservoir.

Any ideas, it has been a headache ever since I bought this boat will never buy used again

dereknkathy

Sorry, not enough info here. Everything we could say would be swag. Start with the basics.

Sydwayz

iTrader: (1)

Is it beeping/alarming?

Snobo4rder08

What more info would you like?


No beeps or alarms

Sydwayz

iTrader: (1)

What temperature gauges do you have? Water? Oil? What temps are they reading when have it running after a few minutes?

Also, the coolant in a 496HO is only good for 7 year or so TOPS, regardless of hours. If you do not have record that it has been changed, it likely needs to be. If it is not BRIGHT pink, it's bad. If it is darker and metallic in color, it's silting up and not flowing/cooling well. This doesn't sound like the only thing you have wrong, but could be a starting point.

Can you get a video of it running? I don't know what gravel in a motor sounds like; as I've never experienced that condition.
Has it ALWAYS had this noise? At what RPMs? If so, this noise you hear may just be your internal flappers inside the exhaust tips.

Snobo4rder08

Only temp gauge I have is water temp and reads right in the middle after warm up.

The coolant is a darker red color and when motor kept shutting off it was coming out of the cap in small amounts.

I also think the ticking I hear is in the exhaust but just trying to give as much info as possible.

This is my first off shore style boat

Just put a brand new 26p bravo 1 on it and it only gets 4600 rpms at 62mph on gps but I feel under low rpms there is vibrating but again maybe that is just normal

Also should note it has cmi headers, corsa captains call, and whipple ecm tune

Questofpower

I would recommend finding a mechanic in your area that is familiar with the 496ho and have the motor scanned. It sounds as if you are having a cooling issue. I know you said the water temp gauge is right in the middle but that doesn't help any of us dignoise your issues we need to know the tempature. You should never have antifreeze bubble out of the overflow tank.

Here are all the guesses that I can come up with.

Overheating
Your seawater pump is bad not working properly. Most likely
You have a restriction in you raw water side of the cooling system (heat exchanger tubes clogged maybe)

Rough Running

Probably needs a new set of spark plugs, not sure which ones you need with the ECM tune.
Could use a new set of spark plug wires
Bad Fuel
Needs fuel filters depending on S/N could be a few different types
Fuel injectors could be clogged up if you have a gen III cool fuel system the paint inside the cooler could have flaked off and clogged your fuel rails/injectors.

Lack of RPM
Most likely the engine is in Guardian mode protecting itself from other adverse conditions reducing your available power. Overheat, IAC Fault issue

These are all issues a good mechanic that understands the 496HO should be able to pick out with a scan.

BUP

iTrader: (9)

anti freeze darken is from overheat as well. Where in Texas did you buy the boat and from whom ? This app is not stock so to pinpoint anything without ears, eyes , hands, scan and testing tools one is throwing huge darts with a small dart board period. Your location is ?

Buying a hopped up 496 in most cases is not a good choice because many whom think they and or can be done, only ends up being a huge headache period. Also sounds like you did not get a survey and mechanical inspection done. Totally bad move on any buyers part. There is more crap used boats on the market than good mechanical boats for many reasons.

the engine is guardian mode and or not running on all cylinders - start with basics. Fuel samples, fuel pressure testing, spark testing, compression and leak down testing. Examine spark plugs and run on a portable fuel system and scan the engine.

BUP

iTrader: (9)

My guess would be voltage / and or water pressure / overheat issues / and possible exhaust manifold overheat for the shut down. Again a left field guess. Just because you have no alarms means nothing period and whom even knows if you have a working alarm or one that works. So lets ask from the start - If you turn key to run position NO ENGINE Start -- do you hear the self test beep (alarm) ?

Also without an alarm hooked or inactive does one know that will set fault codes and could be one of the problems and in some cases engine shutdown ? This pertains to ecm 555 and Pcm 555 and up ---- marine computer controlled engines Mercruiser side of the coin among other engine manu's as well.

BUP

iTrader: (9)

CMI headers - what was done with and or to the exhaust overheat / overtemp sensors ? One can not just unplug them or leave them out with the ecm / pcm 555 -- that parameter is in the mix (stock tune ) or even recal tune. Are they incorporated still in the mix ? Or were they turned off by the reprogrammer of the PCM ?

Do you even have an PCM 555 computer installed for this 496 app ?