[rogie 80]

I have a 1999 225 2 stroke yamaha that shuts off all the electrical at max rpm
it will then restart in @ 20-30 seconds
runs great until I give it the full throttle...any help is appreciated

[rogie 80]

test

[rodbolt]

when you say its electrical, have you watched the tacH, does the tach display go away?
at high speeds,if its EFI , low fuel rail pressure can shut down almost as fast as the kill switch can.
without a model number its hard for us to accuratly know which 225 we are discussing.

[rogie 80]

yes , the tach and all the other electrical components go blank , I then bring it back to neutral and the power resets. It acts like it is going to ground without blowing any fuses model is 225txrx 99 thanks for replying

[rodbolt]

more likly going open circuit, shorts are easy to find as they blow fuses and burn wires.
TXRX should be an OX66.
what your gonna need to look for is battery cables.
if the tach drops offline then it indicating a power loss.
look for battery cable integritey then trace the red wire fom the starter solinoid to the ign switch then the switch.
when I get back Ill try to look up something more specific.
but your describing a power loss to the keyswitch from the pickoff point at the solinoid or a ground loss.
lose either and the injectors and fuel pump shut down as well as the tach.

[rogie 80]

Thanks Rodbolt, I checked the batt cables all look fine I am curious as to why it seems to all go to ground all at once when I jump on the throttle and not when I am just cruising around. I use the boat in the SF bay as well as the Pacific ocean so it flies around and bumps so a bad cable or short should happen frequently. I also just had a 100 hour total service done, the gas tank is new, batts are new , all new filters and thermostats,etc.
Just shuts off at high rpm and will then re-start when I bring the hand control to neutral and re-set the key

[rodbolt]

forget shorts, shorts are easy as they either burn wires or blow fuses or both.
your gonna be fighting a loose or corroded connection.
can be at the batteries,battery cables or main relay.
but shorts burn wires and blow fuses.
at wot your engine needs about 9 amps ,not volts, just to keep itself running.
if it cant get it the tach will be one of the first to drop off.
drawback is it has to be dead to start testing circuits.

[rogie 80]

Thanks, I will change out the cables and the battery select switch just to be sure.
The batts are new.
At full throttle I should get 9 amps? Where would I check with the meter for proper amperage reading.
I will keep you posted when I get it back in the water...Thanks again Rodbolt

[Lone Duck]

Could a wire in your throttle box be getting moved or shorted when you push the throttle to the stop? W O T? Or at the carb linkage?

[rodbolt]

the engine makes about 30 amps, the engine also consumes about 9 of those amps.
there are various meters that can be used inductivly to test current draw.
if the engine is consuming more than it can get it shuts down.

[rogie 80]

I will check the throttle linkage as well and I will have the local dealer ( Boat and Motor mart check the amperage draw after I replace the cables as I have found some small corrosion at the battery select switch. That may be my loss of current which would explain the WOT shut down
Thanks both of you guys