I have 250 pro xs, 1B839289 serial number. I have replaced fuel filter, fuel line and bulb as well as pulse pump in the last 6 months. The motor has started dying when bouncing in rough water when running at mid speed. This happens when wave crossing or porpoising due to incorrect trim.
Thoughts
Make sure the connections on your starting battery are tight???
Last edited by jrspop; 05-13-2018 at 10:09 PM.
Keith Broussard Caney Lake, Louisiana
2000 TR21 2000 Mercury 250 Pro XB OG980775 14" hydro plate
Check your plug wires. I was running in some ruff stuff a few weeks ago at about 4500 rpms for about 10mins. I got to my spot and fished for about 30 mins. Started back up and it would not go over 2200 rpms. One of the plug wires had popped off during the ruff ride.
My first thought is a loose electrical connection. Since it takes a jolt to cause the issue.
Those can be a booger to diagnose........... could be anything from the kill switch to the fuel pump and many possibilities in between..
Well I have checked plug wires, kill switch and battery. Could this be from an electric fuel pump going bad? I hear the fuel pump running as the motor dies and the boat is coming to rest. The fuel pump stops almost immediately at that point and I can crank up and take off .
Check MPR.
Can you translate the acronym mpr?
Sure, Main Power Relay.
Notice you are in LA. Salt water corrosion is a possibility. Cannon plug on mine corroded. Cannon plug is main wire harness connection. I would also clean all battery connections with big connections at battery installed first.
Why not just grab the harness at certain areas, give it a shake to see if you can reproduce the issue. You are kinda describing something that can be reproduced due to the fact that you say it happens in rough water. I bet if ya spent some time thinking of common connection places you will find your issue. And don't forget the main relay either.
thank you
I replaced the mpr as suggested and also started up on muffs and shook,pulled and rattled anything that I could see that was electrical: not an engine miss at all. Is there a test that can be performed by a mechanic to track this down?
Must be able to duplicate the complaint in order to find the cause.
I suspect it to be in the keyswitch harness connector (or an adapter used to make the connection). Disconnect these, make sure they are clean, reconnect PROPERLY and see if the problem persists.
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Don, what is the part number for this harness. I am thinking of running the harness on the deck to isolate the cable.
thank youI have had a mechanic look at it and check the fuel and air which checked out. He ran the motor on water and could not duplicate the issue. He loaded on the trailer and ran in gear at 3500 rpm while shaking wire connections with no results.
this weekend it happened again at speed from wind induced waves. I was running 4100 rpm and I noticed when the motor started missing that voltage was 13.9. It also held the speed while it was cutting out until I tried to accelerate through it and then started choking down and losing speed until it finally went dead.
Do you, by chance, have a ~2010-2013 Triton with the start/stop button "feature"? I had similar issues to yours that were cured by having the start/stop functions converted back to the key switch. Best of luck!
Yes jb it is a 2011 triton with push pad start. Where did you get the new switch?
On my 2013, I have a regular key switch under the shifter that had to to be turned to "on" in order to use the start/stop button. The fix was to change the connection at the key switch to eliminate the start/stop button and use the key switch for it's intended purpose. I had this performed by my dealer. It was literally a 15 minute job for them. They got instruction from the factory at the time. I believe all it entailed was to unplug the connector to the push button and plug the ignition directly to the key switch with an existing connector. At one time there were some discussions on the subject over on the Triton board. You may be able to find them by using the search function. I had several instances where the engine completely lost power at speed and one failure to start that I am 99% sure was the fault of the button. Have had zero issues with either since eliminating the push button "feature". Best of luck with yours.
thanks JB, I have the same regular key switch. I tried to contact a tech at Triton; but they are taking the week off. A wiring schematic would be helpful but I have not had any luck finding on online.
It's been a couple of years, but to my recollection no additional parts were added. The solution was simply to disconnect the one connector to the dash start/stop button and connect an the existing "normal" key switch connector that was pre-rigged in the boat. Sounded like there may have been a 3-way connector or some such arrangement. It may be obvious (or not) if you remove that little access panel that holds the key switch. It really was a 15 minute job for the tech. Never did understand the need to over complicate this simple, but very necessary operation.
I am going to look at it this weekend. If the key switch is designed to operate when there is a fault with the push button; it seems I would only need to unplug the power to the push button to activate the switch. I also wonder if it could be the kill switch. But the motor is not dying when at speed; only missing.
Thanks for giving me another thought on this. I will reply when solved.
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