Hot Regulator

[BAISICNORTH]

On my 1998 Yamaha 100 hp V4 I am having a problem with the regulator getting very hot. When the regulator gets hot the motor seams to cut back on the firing to the cylinders. I have checked the regulator, current only flows one way. I have disconnected the temp sensors on the cylinders. If I take a cup of water (a no-no)and poor it on the regulator the motor jumps back to life. Any Ideas???? This only happens under load.
Thanks for any help.

Jim

[Ken]

Jim,
It sounds like there is just too much load on the regulator.
I would monitor the voltage and current that the regulator is having to put out. You will need two multimeters for this. Let one monitor the voltage and for the other, you will have to get the leads in series with the regulator output and a meter that can handle at least 30 amp.
Your regulator should not be putting out more than 20 amp and at a voltage of 12. If the meter is showing more than 20 amp, then you may have a bad battery. If less than 20 amp and the voltmeter is showing less than 12 volts, then I would suspect a bad rectifier/regulator assembly.
Good luck, and let us know what you find out [img]smile.gif[/img] ,
Ken K

[Ken]

Jim,
As an after-thought to my previous post, the rectifier/regulator assembly should have current limiting built into it. On my 2000 C115, the "alternator" output is rated at 20 amps. Yours is probably the same.
If you were to do a current test and found that the r/r assy is putting out MORE than the rated output, then I think that would cause the r/r to overheat.
The r/r of course has voltage regulation and should put out about 12.5 volts at idle, and increase from there to about 14.6 volts as the starting battery charges fully and the rpm of the motor increases to something above 3000 rpm.
Bottom line, if your battery is at least three years old, I would replace it. This may solve your problem, but I really suspect you have a bad r/r assembly.
Try the voltage test - you can monitor the voltage directly across the battery with the motor running. If the r/r does not put out the above voltage, assuming a good battery, then it probably is bad.
Hope this helps [img]smile.gif[/img] ,
Ken K

[jb123]

on your motors, im not sure as the larger ones do, water actually cools the regs( learnt that from boats.net)in line with the pisser line prior to going OUT,runs thru the reg and cools it.

[Ken]

Hey jb,
You're right about the cooling line for the r/r on the larger motors, but I'm pretty sure none of the V-4s have it - at least mine does not.
Ken K [img]smile.gif[/img]

[jb123]

well ....sounds like they need it !!

[BAISICNORTH]

Thanks for the suggestions. This regulator is not water cooled.
Could a bad regulator make the motor run rough?(when it gets hot the motor seams to cut back on the firing to the cylinders).
If I disconnect the red wire from the regulator am I just running off the battery and at this point the boat should run with out missing?

Thanks for all your input.

Jim

[Ken]

Jim,
I really don't know if the CDI has 12 volts from the r/r and battery circuit tied to it or not. Looking at the diagram for my 2000 C115, it does not show 12v going to it.
You could try removing the red wire to the r/r - but don't do it while the motor is running.
Did you check the voltage across the battery with the motor running and when the r/r gets hot?
Ken K