250 V76X V6 - Starts, Idles, Revs up in neutral but not in gear.

[jeff6645]

Greetings,

This is my 1st post to iboats forum so be gentle..

I just purchased a used boat with a Yamaha V76X V6 250hp outboard, took it out today but ran into a problem: It starts right up and idles fine but when you put it in gear it will only run at 1800 RPM, put it in neutral and it revs up fine. Got an alarm too, water pump is pumping, engine doesn't seem to be too hot (I can touch it for a few seconds). I did notice a lot of oil in the water. Called the original owner he said it was running fine the last time they took it out, but it has been setting for 6 months... also said the calibrators were just rebuilt about 8 months ago...

This is what I have tried today dockside: replaced all plugs (they were very oily), replaced the gas/water separator filter poured the contents in a clear jar and let set for an hour and didnt see any water in the fuel. Tighten all gas fittings (2 were damp around the ends - leaking).

I don't know the year model of the motor, can someone tell me how to find that info? Original owner said he thought is was 95 or 98 but not sure...

Thank for your time and help,
Jeff
Mobile, AL
23' 1974 Seacraft

 

[andrewmac]

Re: 250 V76X V6 - Starts, Idles, Revs up in neutral but not in gear.

Hi Jeff,

Your engine has a few safeguards in place to protect it. It sounds like the engine is trying to protect itself now. On your gauge there should be an icon that blinks when the alarm sounds. Some alarms limit power so try to determine what alarm it is. It could be an overheat or low oil in the engine oil tank. Is the engine physically hot? It is possible to have an overheat even with good cooling water flow if a thermostat is stuck. The engine oil tank has a switch next to it where you can manually turn on the pump to fill the tank. If the oil level is low try hitting the switch to see if the tank fills. The alarm should stop when the oil level reaches the bottom line on the tank. If oil level is the problem the most likely culprits are either a clogged in-line oil filter located on the boat mounted oil tank, or a bad oil level sender.

Good luck!

 

[jeff6645]

Re: 250 V76X V6 - Starts, Idles, Revs up in neutral but not in gear.

Thanks for your suggestions!

I am betting it has something to do with oil level or oil sensor; the reservoir on the side of the motor was less than half full and one of the main tanks is less than half full. The boat used to have dual motors and when they swap them that left everything for the second motor in the boat and still attached. I bet I fill the wrong oil tank. I will be removing all the extra stuff. The boat needs a some TLC in the below the deck area.

Hopefully I can get it back in the water one afternoon after work this week to test it out.

Thanks again for your help,

Jeff

 

[jeff6645]

Re: 250 V76X V6 - Starts, Idles, Revs up in neutral but not in gear.

Okay back at square one. Thought I found the problem, I broken brown wire going into the sensor on the main oil reservoir. Repaired it filled the tank and filled the tank on the side of the motor. Removed the line going into the tank on the side of the motor and it has oil coming out of it, but not much oil.

So off to boat launch to try it out... same song and dance... starts and idles and even revs up in neutral, but only 1800 RPM in gear. Did get the alarm alarm to clear.

Any suggestions? How much oil should be coming out of the line going to the motor? Also still a lot of oil in the water...

Thanks again for your help!