yamaha 90TLRA charging/running volts output?

[SeaDawg3]

OK, recently swapped out the analog gauges for a pair of Yamaha Multifunction gauges, speedo and tach.
One thing I notice is the Volts reading is higher now than before with the new faria volt gauge. I was seeing a max of 14 on the high side closer to the 15 mark.
now that the digital gauge is operating I`m seeing between 15.2 and 15.6, the max being 15.6.
When I crank the Fusion RA50 radio up, the volts will settle at 15.2.

what is the acceptable max charging/running volts for the 90TLRA? do I need a new voltage regulator/rectifier?



apparently this has been running like this for a long time. Only when I purchased the boat did it then have a volt gauge. That`s how I noticed the dip in volts when trimming up or down, which I can assume the trim motor draws a crap load of amps.

thanks...

[SeaDawg3]

while searching the forum, found this:

Within the limits of the lighting coil a higher voltage should provide a higher current which will recharge a battery faster.

13.6 volts seems low but if a battery is depleted you may see this voltage value until the battery gets close to being charged. What is happening is the current demand of the battery exceeds what the generator can provide. Once the battery is close to being fully charged the voltage will rise.

Most Yam regulators will output 14.5 volts to a fully charged battery. Some run at 15/16 volts however.

If the battery is not charged or if the battery is defective all bets are off.

makes me feel a little better now.

after a few hours from the last ride out, I operated the trim so I could flush the engine, so take account any current loss...

the volts spec`d out at 12.72 a minute afterwards. Battery appears to be well. and only 5 months old.

[SeaDawg3]

Does the output matter if I have several electronics running while underway?
Any comments?

[boscoe99]

Measure the voltage of the battery without the motor running. A fully charged battery will be approximately 12.7 volts or so.

With the motor running the voltage will be above 12.7 volts if the generator is producing electrical power. On most of the bigger Yams it will be about 14.5 volts. Smaller motors don't appear to be as well con*****ed and the voltage can be somewhat higher.

The voltage seen on a volt meter with the motor running will vary based on the capacity of the generator, the type of voltage regulation that is used and the loads that are connected to it.

The power trim and tilt unit takes a bit of current to operate it. It is normal to see the voltage drop on a volt meter when the trim motor is being used. Same thing with the starter motor.

[SeaDawg3]

Measure the voltage of the battery without the motor running. A fully charged battery will be approximately 12.7 volts or so.

With the motor running the voltage will be above 12.7 volts if the generator is producing electrical power. On most of the bigger Yams it will be about 14.5 volts. Smaller motors don't appear to be as well con*****ed and the voltage can be somewhat higher.

The voltage seen on a volt meter with the motor running will vary based on the capacity of the generator, the type of voltage regulation that is used and the loads that are connected to it.

The power trim and tilt unit takes a bit of current to operate it. It is normal to see the voltage drop on a volt meter when the trim motor is being used. Same thing with the starter motor.

good to know, bc it acts like a bad ground, when all grounds are good.

yes, battery at rest is 12.7+ volts. as mentioned, I normally saw the higher end of 14v on the analog, which has it`s discrepancies.
Assuming the multifunction gauge is more accurate, I immediately noticed 15.2-15.6.

so being the 90HP is considered a small engine...

[CatCam]

good to know, bc it acts like a bad ground, when all grounds are good.

yes, battery at rest is 12.7+ volts. as mentioned, I normally saw the higher end of 14v on the analog, which has it`s discrepancies.
Assuming the multifunction gauge is more accurate, I immediately noticed 15.2-15.6.

so being the 90HP is considered a small engine...

I have the same motor and mine shows 14.4 - 14.6. However right before my Voltage regulator fried it was reading high. I'm not trying to alarm you but this is what happened to mine. I'm assuming all of your connections are good and you're not using wing nuts on your cranking battery.

Just for kicks I'd try it out with another battery just to rule that out.

[SeaDawg3]

I have the same motor and mine shows 14.4 - 14.6. However right before my Voltage regulator fried it was reading high. I'm not trying to alarm you but this is what happened to mine. I'm assuming all of your connections are good and you're not using wing nuts on your cranking battery.

Just for kicks I'd try it out with another battery just to rule that out.

thanks.
stainless washer/lock washer and nut on the battery terminals. I suspect the rect/reg is original, so it wouldn`t hurt to replace it before there is an issue.

I have a 2 yr old Everstart that came with the boat on the bench, I replaced it with a new Everstart 24DC back in May and the date code is 4/13.
However the battery was a little low, so I added the necc water. But it holds a charge well, starts the boat well and I don`t see an issue with the battery, currently it is static @ 12.78V...

Now the 2 yr old Everstart on the bench. a few days ago I decided to toss the battery tender on it and she took a while before going green. then did it again the next day. I let that battery sit for 24 hrs and checked the static volts and it is @ 12.88, seems like this one still has some life left in it.

If the new reg does not change the volts, then at least I`ll have a spare in the tool box...

[CatCam]

Yeah, if the regulator does go it isn't pretty and if it takes out the CDI parts alone will set you back $600+......ask me how I know.....

Here is the link to my saga a few years back -- but mine was probably because I had a loose wing nut on my battery........
http://www.yamahaoutboardparts.com/f...p-th16356.html

Live and learn.

You didn't say what year your motor was but from what I've heard, Yamaha did change the Voltage Regulator because of overheating issues.

Keep us posted.

[SeaDawg3]

it`s a 2002 90TLRA,

[CatCam]

it`s a 2002 90TLRA,

I stand corrected, I have the F90TLRC 4 stroke but the charging system is virtually the same.

[zenoahphobic]

Battery size

If it has not already been looked at, the capacity of the battery should be say larger than 600 CCA. If your battery has a small capacity then it will charge quickly (to overcharge), and loads will make the voltage drop far more quickly.
The larger the battery the more stable the voltage.

So a further test could be get a large Amphour battery, make sure it is fully charged !, and then run engine etc and see what the voltages read.

And if this battery is discharged with engine off by some of your electronics for awhile, and the engine is restarted and run for a short while and the voltage rises to over 14.5V then you have a good charging from the engine but a faulty regulator.

[rodbolt17]

go to your local dealer that you buy stuff from. have them research tech bullitens.
there was one for some of the inline engines back about that time frame.

[SeaDawg3]

If it has not already been looked at, the capacity of the battery should be say larger than 600 CCA. If your battery has a small capacity then it will charge quickly (to overcharge), and loads will make the voltage drop far more quickly.
The larger the battery the more stable the voltage.

So a further test could be get a large Amphour battery, make sure it is fully charged !, and then run engine etc and see what the voltages read.

And if this battery is discharged with engine off by some of your electronics for awhile, and the engine is restarted and run for a short while and the voltage rises to over 14.5V then you have a good charging from the engine but a faulty regulator.

The battery size is good @ 690.

go to your local dealer that you buy stuff from. have them research tech bullitens.
there was one for some of the inline engines back about that time frame.

I don`t purchase from a local dealer, so I`ll have to do some digging. thanbks

[SeaDawg3]

just waiting on some parts.
in the meantime, both batteries, new and old can sustain a full charge and settle in @ 12.7 -12.8V.

[BQUICK]

I had high charging voltage 15.5-16. Found that two of my 4 batteries were low on water. Added water and now max of 14.7 but only after running for a while.