1997 4.3 stalling issues

[Troncd]

Hi everyone. I picked up a new to me boat a few weeks ago. 1997 Maxum 2000 SRL. It has the 4.3 mercruiser. Still learning about these boats so bear with me and my ignorance.

When i I purchased the boat I was able to test it on the water as the owner lived at the lake. I was able to run it about ten mins or so and everything operated as it should. I ended up making the purchase, and trailering it home.

Thant evening my wife and I took it out for a couple hours. Never ran it more than 20 minutes straight but it ran great w zero issues until back at the ramp where the tilt/trim up started working intermittently. I repaired that easily w a new Solenoid.

Took it out 2 more times w seeming no issues except on the second of these two times it died under acceleration 1 or two times. Each time it did this it would start right back up and gave me more more issues for decent amounts of time.

Fast forward to the fourth time time I took the boat out. Ran great from the ramp for about 20 mins. Then, after stopping to hook a tube up it died under acceleration. Sometimes right after giving it throttle, others right after hitting plane. Longest t would go is maybe 10-20 seconds. Pulled tube in, and it rode fine for 3-4 mins before same issue arose.

Decided to head back to ramp. Started getting much worse. Wouldn’t go more then 10 seconds before stalling, sometimes less. Got towed about 30 mins by my dads Bayliner then decided to give it anouther try at which point it ran fine for 8 or so minutes to get us back to ramp. It died right when I put it on the trailer.

After reading and googling, I checked fuel pickup tube. Clear. Changed anti siphon valve. It was clogged w hair like material. Cleaned filthy spark arrestor. Changed inline fuel filter and water separator. Also checked carb inlet filter. It was clean. I was hopeful that it was the anti siphon valve.

Today i I had the chance to take it out after swapping out the filter and anti siphon valve. Ran great for 10 consecutive mins. After stopping, shutting off and restarting, the same issues arose. It never got quite as bad as before, but it did die several times before making it back to ramp. It was also just me so less load than before w the family onboard. At home i checked the anti siphon valve again hoping it would be clogged but it was perfectly clean.

Couple of notes: when this issues first arose, I ran it in neutral and it was always fine. Would rev up and never die. Only had problems under load. Also, it always immediately cuts off. No sputter or hesitation, just dead. And third, it always starts right back up.

Any ideas what to check next?

 

[achris]

Did you check the tank vent line? They get clogged up, sometimes with spider or insect nests, and that would starve the engine of fuel...

Chris......

 

[Troncd]

I did not on the water. When I got home though I disconnected it at the tank and blew into it. When I did so, I heard bubbles in the tank and even a small amount of fuel came out of the nipple the the vent tube hooks to. I guess air hit the filler cap, and traveled back down the filer tube. Should that happen? The vent is built into the filler cap.

 

[Rick Stephens]

A couple thoughts for you. Personally, I'd start with a thorough carburetor cleaning and rebuild. Makes a lot of folks nervous getting inside a carburetor, but it is worth the effort. Pay attention to all the little ports. Spray air and carb cleaner through each and insure they are clean. Make sure the float level is exactly right.

The other part of this is even tougher advice but will serve every new used boat owner well. Go through everything. Do a complete service of your new to you boat. A missed service item can end up costing you an arm and a leg, worse, a break down at the wrong moment. Pull the stern drive and check everything. Drain and inspect the gear lube. If it's in perfect condition you can reuse it, although I wouldn't since you don't know what it is or how old it is. While drained, split the upper and lower halves of the drive and pull apart the raw water pump (I'm assuming you have an Alpha 1 drive) and inspect the impeller. Replace as needed. Check and lubricate the u-joints and inspect gimbal bearing. Carefully look at u-joint bellows. Go through the motor maintenance like your safety, or your wife's, depends on it - It very likely may.

This forum is here to help do it yourselfers maintain and repair their boats. There are only two ways to keep a boat safe, DIY or pay someone to do it. Boats are expensive to operate. No one gets away with ignoring maintenance for very long without it costing them. My advice is to start now and be safe. No telling what the previous owner ignored.

Happy boating.

Rick