F150 overheat warning alarm/trim reading

[swagg68]

Just brought the boat out for the first run in a couple of months. 2004- F150 when I noticed the trim reading on the main gauge(RPM, hour meter and trim gauge) was not working when I was trimming up and down the motor. Later about 5 minutes into the run the high temp alarm went off when running low 4000 rpms. Shut down engine immediately because I never had this happen before. The pee hole was spraying as normal, didn't smell anything abnormal and prop/shaft were always in clean water and no obstructions. Cranked motor back up a minute later and no problems cruised about 10 minutes at 1200 rpms then ran it low 4000 rpm for another 25 minutes with no problems. Later when cruising back to the ramp running about 4000 rpms again the high temp alarm went off. Once again shut down and restarted in a minute and ran back to the ramp with no problems.

Read in another post low voltage can set off alarm, checked all cable connections to battery and found one terminal on one battery with semi loose cables. Tightened up cables tight, jilted back and forth trim gauge sensor and now it works, but don't know if random high temp alarm will reappear until I go out. Question, the semi loose battery cable probably my high temp alarm culprit or do I need to invest in replacing a thermostat and water pump? Motor has 70 hrs in 2 years not a lot of run time. Any advice or help appreciated, planning on going offshore in the next week or two and don't want to be stranded.

 

[swagg68]

Re: F150 overheat warning alarm/trim reading

Are there any Yamaha Techs that can help diagnose this problem?

 

[WillyBWright]

Re: F150 overheat warning alarm/trim reading

I'm afraid our Yamaha Guru flew the coop a few months ago. I can tell you that battery problems can cause strange things to occur on any EFI. It has to be big enough, and the connections have to be pristinely clean and very tight. Finger-tight wingnuts isn't adequate. I usually install stainless locknuts to force customers to use tools to tighten them down. We also sell only extra-heavy duty batteries for them. About half of the EFIs that come in with strange problems are battery problems. If the connections aren't loose or corroded, I find that the customer has an inadequate battery. It is either too small, or was marginal to begin with and weakened with age.

There are typically three sizes of starting batteries. By size, I mean cranking capacity. Physically, they are all the same size (24-series). 24M-RD (Regular Duty) batteries are always inadequate for EFIs. 24M-HD (Heavy Duty) batteries are adequate for most EFIs. 24M-XHD is what you want to be confident that you have enough battery. You also need to stay away from Dual Purpose deep-cycle batteries. The largest ones seemingly have the capacity needed, but they are primarily designed to deliver low amps over long periods. They also charge slow over long periods. The Dual Purpose models (most are nowadays) can deliver the needed cranking amps for starting, but they still charge slow. Too slow to keep up with EFIs sometimes.

On average, marine batteries should be good for two years. If properly maintained, they can last three. Four is too old. If this is your third season on a Heavy Duty battery, you might be wise considering upgrading to a new bigger model.

You should also check to make sure your motor is charging the battery. Loose, corroded, or crossed battery terminals can damage the charging system. Voltage should rise with RPMs to about 14.7 volts above half-throttle (that's a ballpark figure). Check voltage at the battery with a voltmeter. Voltage should be higher running than sitting, and voltage should rise with RPMs.

If you do a lot of low RPM operation, it might not charge fast enough to keep up with the demand. That's where that Extra-Heavy Duty battery can save you a lot of headaches over a Heavy Duty model.

Low hours is also working against you. If it isn't run, the battery isn't being charged. You'll probably need supplimental charging. There are a lot of battery maintaining chargers on the market. Considering it's infrequent use, that would be a very wise investment. Not just a typical battery charger, but one that's capable of maintaining a battery by self-monitoring and self-adjusting to conditions.

I hope this helps.

You shold also consider having the water pump impeller replaced. It could be damaged and not putting out enough capacity. Most manufacturers recommend annual replacement, but every three years is usually good enough. Unless it becomes damaged, usually by being starved of water. Sometimes hose flushettes slide out of place, sometimes a discarded plastic bag or seaweed blocks the water intakes.

 

[swagg68]

Re: F150 overheat warning alarm/trim reading

Thanks for the information. I believe this will help quite a bit or at least give me something to start from. I will definitely charge the batteries since they haven't been used much. I do believe they have the capacity I need but I will check them against the info you gave me. Replacing an impeller is something I have only heard about but never done personally. I hope it is as easy as it sounds. I will have to look up where it is even located and then determine which bolts will need to be removed to get to the impeller.

Thanks for the help

 

[zzzzz]

Re: F150 overheat warning alarm/trim reading

Yamaha trim senders are notorious for sticking...trim your motor all the way up and find the sender and trim cam at the steering tube..if cam is intact-lube up the sender and work it up and down...have someone watch trim gauge while you do this to verify operation

 

[swagg68]

Re: F150 overheat warning alarm/trim reading

I think your right. I worked the sensor arm(or at least I think was the sensor arm) up and down and it appears to be working now. Or it could have just been from tightening down on one of the battery posts.

 

[yamamarinetech40]

Re: F150 overheat warning alarm/trim reading

Yep, low voltage will give you problems but I do think you should change your impeller right about now, anyway....two years is plenty....always remove the cowling and feel the heads at the top to see if you really are hot when you get an alarm...and use locknuts like willy said...wingnuts are evil....

 

[swagg68]

Re: F150 overheat warning alarm/trim reading

Sounds like I need to change the impeller. Any quick links on how to change the impeller?

 

[zzzzz]

Re: F150 overheat warning alarm/trim reading

if you want to see parts diagrams go to yamaha-motor.com then click on marine then parts/service and you can view the parts book for your model