Port Engine Headaches in 99 2800 SCR twin 4.3 - Maxum Boat Owners Club

dwarren1919 · 06-16-2011, 08:25 PM

Boat runs fine until it gets warm and then the port engine will shut off and the alarm will go off. Starboard engine continues to run just fine. The port engine will start right back up with no problem. Really only happens at slow speed under 5 knots.... when I'm full speed have no problem what so ever...

Had my cousin look at it....he thinks Im getting a vapor lock because the fuel lines were real hot after letting the boat idle for 20 minutes....

Anyone else have similar problem or can aid in some advice....

Thanks

shrew · 06-17-2011, 02:05 PM

What is the alarm. What does the temp. and oil pressure read on the guages when the alarm goes off? If I recall two fast chirps is low drive lube. One long contant tone is overheating. I could be wrong.

dwarren1919 · 06-17-2011, 07:37 PM

It just the long alarm when your engine is turned to the on position without the engine running....engine temp and oil pressure are fine....

seapuppy · 06-17-2011, 08:31 PM

then check all connections to the oil pressure sender, temp sender and the oil reservoir sender....one of them is either off or corroded...

SP

dwarren1919 · 06-21-2011, 02:31 AM

Thanks....we think its the oil pressure sensor which is killing the fuel pump....

dwarren1919 · 06-24-2011, 01:02 PM

Well we changed the oil pressure sesnor and that didn't fix it....any other ideas....

shrew · 06-24-2011, 01:27 PM

Quote:

Originally Posted by dwarren1919

Boat runs fine until it gets warm and then the port engine will shut off and the alarm will go off. Starboard engine continues to run just fine. The port engine will start right back up with no problem. Really only happens at slow speed under 5 knots.... when I'm full speed have no problem what so ever...

I just re-read the post. Does the engine stall, and THEN the alarm goes off as a constant beep? If so, I believe that is normal. The alarm is probably the alarm 'test' mode similar to when you initially turn the key to acc. If I recall the purpose is to clearly notify you that the engine has stalled and is no longer running. You state that you can restart it wiithout any issues and can run at higher RPM's without any issues.

This is a 99, so I assume you have a carb. Could this be a situation where the choke is not opening preoperly when the engne warms up, causing a rich condition? Or the jet is partially clogged so when the choke opens it creates a lean condition? Have you tried slightly increasing the RPM's after the engine has warmed up a little bit, but not all the way. I wonder if giving more fuel when the choke opens prevents the engine from stalling?

Just a thought. If that doesn't work, I'd still be looking at the easy stuff next, like car next.

ss3964spd · 06-24-2011, 02:28 PM

Interesting.

Are you certain that the oil pressure and temp is fine after the engine is warmed up and running at idle speed?

Would help to know the exact scenario under which the engine stalls. If, say you fire both engines cold, leave the dock and motor out at idle speed only will the engine stall at some point?

Carbed or FI?

Dan

dwarren1919 · 06-25-2011, 02:09 PM

Yea all temps are fine....and I have tried to bump the rpm's up and that hasn't helped only way it works is if Im at full throttle....It is carb and this last time out the engine did not want to re-fire after she cut out had to bring her in on one engine and now it smells like fuel and i think its flooded....Went down a day later and it started but only ran for 2 minutes and shut off again and wouldn't start....now it seems like its flooded again....Im at a loss and Dan it would run fine for a 30-45 minute time period everytime and then it would cut out......

Tommyfmu · 06-25-2011, 02:56 PM

Admitted novice here, but a thought or two. Since the problem is getting worse, and now smells like fuel building up, and cuts out at low speed but was working well at higher RPM's, I would think that perhaps the air intake to the carb is being blocked. Low speed the air flow is low so causing too much fuel to be sucked into the engine and flooding. High RPM's were working b4 due to the sheer velocity of pulling through the air into the carb, but maybe more clog buildup at this point. Maybe try removing the flame arrestor and thoroughly clean with solvent (carb cleaner etc) and inspect for any hindrances to the carb intake, and clear. A dirty flame arrestor is a violation anyway so couldn't hurt

shrew · 06-27-2011, 12:13 PM

Interesting. I would take a long look at the carbs. float valve, jets, choke, everything.

ss3964spd · 06-27-2011, 02:00 PM

I'm thinking carb issues also - especially given that you're smelling gas (BTW, since you are smelling gas be sure you open the engine cover(s) and run the blower(s) before you crank either of those 4.3's). Easiest next step - swap the carbs from one engine to the other to see if the symptom follows the carb.

Dan

Capt Al · 06-28-2011, 02:36 AM

To me it sounds like a carburetor problem. I've had both my 2 barrel carbs rebuilt. A gummed up carburetor will cause all kinds of performance issues. Also make sure that the butterfly is in the full vertical position when the engine is warmed up. If it isn't vertical(open) this can lead to stalling and starting problems. Check the choke power cable (not loose or corroded) and the ground wire. Besides the choke repair you'll need to change your plugs and of course it's good to change your fuel filter once a year.....

dwarren1919 · 06-29-2011, 02:22 AM

We took it for a ride and the one manifold was hotter than the other engine....we are going to put a new impeller in to see if that works....thinking the maifold is kicking off some extra heat which is causing the fuel pump to get hot and shut off....

maxumista · 07-08-2011, 11:43 PM

We are having this same issue with a 1999 3000 SCR. We are getting ready to get a remanufactured carburerator.

Please, I'm curious!! What was it??

Thank you,
Lisa

seapuppy · 07-09-2011, 01:43 AM

welcome to the zoo Lisa......

SP