225 sho blowing fuse. help please

[pstephens46]

At some point point OP mentioned several codes showing on YDIS.

I remember Rodbolt mentioning that low voltage to various sensors can cause codes to be registered. Hit the trim and voltage drops and codes are triggered? I only say this to perhaps keep the OP from getting sidetracked. There seems to be some focus needed here.

[dray0151]

I would be much more interested in finding a short than looking for codes as you say, they are probably the result of the power fluctuation, one bad signal from a sensor because of a power drop and a bunch of others might also go out of wack as the ECM thinks there are big problems. He also did not say if the YDIS codes hours were, were some of them maybe old codes from another event? the two problems may not even be linked other than some wiring problems that are more extensive than just the EVT but also in the T&T. could have several connections bad. I think he did say there was a loose one on a battery with a wing nut he corrected.

[panasonic]

No doubt the fuse blew on last touch of trim before i lost throttle accelearation.

It seems very strange that this problem started when the Trim was used...and continues ever since. That to me is a clue. I know that they are completely separate systems.

Do the wires for the Trim tilt run through the same part of the harness as the EVT wiring?

[HarrisonDawgs]

99aym...good last post. Makes sense to me. Right now the problem is in the hands of a shop technician.
dray...all codes I listed tripped came at same hour on clock (last time I ran it). However, I do agree that the last couple of codes (mainly APS) were only tripped because there were previous codes tripped milliseconds before. Only fitting for ECM to realize the accelerator position does not match the throttle position since throttle is disabled and spring has returned it to ground zero.
Panasonic...Yes, very strange and I assure you it is in play some how some way. My personal concern is the close proximity of the trim solenoid to the fuse/relay panel. I agree with Kirchoff as well but pour a tablespoonful of water on your keyboard right now and see if it responds according to the circuit diagram. Kirchoff still applies but when your technician takes it apart next week and water has evaporated he will likely be scratching his head.
99yam...agree with your last line also. I think there is a chance that ground terminal at battery could have been loose and the partial ground (cable loose and arcing) could cause some serious surges when trim motor came on board. Drops and spikes can definitely damage electronics or surge protectors wouldn't sell.
Thanks to all. I will report the findings when I get them. I certainly hope it is a simple short somewhere outside of the major components of the circuit. That would be the least expensive and potentially restore some of my faith in Yamaha. Hard to be proud of a motor that is on its 3rd powerhead in 7 years and multiple other problems as well. Here's hoping we are squeezing the last bit of juice out of the lemon...

[99yam40]

Interesting that you say the throttle is pulled back by a spring, I thought that the ETV motor turns in forward and reverse to set the throttle position.
I have no idea how this motor actually works.

what took out those power heads

[panasonic]

Yes what took out those powerheads is a very good question indeed. That would mean that harness has been off the engine three times, assuming that the harness was never replaced.

Many problems could have been created by removing and reinstalling wiring harness if not done properly. I still say there is a short in that harness that the OP has just not found yet.

Hopefully he has a good mechanic find it in short order.

[HarrisonDawgs]

Interesting that you say the throttle is pulled back by a spring, I thought that the ETV motor turns in forward and reverse to set the throttle position.
I have no idea how this motor actually works.

what took out those power heads

I'm making the assumption of some spring tension as I originally thought the throttle plate could be stuck straining the motor. Manipulated it by hand and it "felt" like spring tension to return it to the closed position. Not sure this is the case and I agree the motor opens and closes it but I assume a spring tension is in place to close the throttle in an otherwise catastrophic condition where it could potentially stick wide open throttle.
Not sure what went on with heads. I was owner for last warranty replacement and I was told it was something internal as pistons, rings, bore, valves, rods, bearings all looked perfect. Was shipped back to Japan I think. Mechanic blamed the second powerhead failure on the low morale in workers from Tsunami (2011 If I recall correctly). This obviously is a weak guess but I took it they were having various quality control issues for a brief period there...not acceptable but understandable. As far as the original head, I have always assumed it was due to some of the early production problems. I have heard there was a recall of several months worth of production to fix various issues they were having. I assume this head let go before the recall was initiated but I can't be sure. My personal belief is that in an effort to create a high compression ratio 4 stroke in the lightest weight possible (so they compare to 2 stroke equivalents) we have a situation where we have compromised too much. One such example is oil drain plug for motor. Yamaha recommends oil extraction claiming it is as effective as draining. I suspect they are doing this to hide the fact that the aluminum alloy is so lightweight and weak they know there is a huge chance of stripping the threads merely replacing the plug. Happened to me. Torqued it to specs and immediately had an oil leak. Eventually solved by tapping it and using an oversized plug but when I used the tap the lightweight aluminum felt more like butter. I used thread sealer as a precaution and watched the garage floor for months under the skeg. Decided to never remove that plug again and resort to extraction. Heard many similar stories. I'd feel much better if Yamaha should extend some good will on some of this considering the track record of this serial number but since I am the second owner and YES warranty expired about 12 months ago I don't look for it to happen. It's a shame too (for me anyway) because I'm not having the confidence most yammy owners swear by. It's a marvelous looking machine, strong running with high tech features that all look and sound good on paper but none of that is much good if it's not dependable. Still crossing my fingers it's something simple and I'm just an idiot for failing to find it.

[rodbolt17]

Yamaha did have some thrust bearing issues with the 4.2L.
some rotor issues with the 5.3L.
Yamaha does not have issues with the electronics.
that is why most tech's cannot PROPERLY diagnose electrical issues.
most have NO actual training nor care to read.
electronics can be hard cause you just cannot see it. but it does exist.
kinda like this thread has moved all over from hull wiring to APS sensors and NONE have anything to do with the 10 amp ETV circuit.
Voltage is a simple measure of electrical pressure also known as EMF.
current is a measure of electrons past a point and is typically measured as amperage.
try to move 12 amps past a 10 amp protection device means most likely that protection device just opened the circuit and stopped the flow.
yet the input to the protection device will still show a potential electrical pressure from that point to ground.
think of it as water in a pipe.
the oil change thing is just that. screw a stainless part in an AL body and soak it in an electrolyte and rotten AL is simply what you get. I have no idea why there is even a drain plug. it is stupid to use a drain plug.

[boscoe99]

This has evolved into one of the strangest threads that I have read in quite a while.

The term "shotgun debugging or shotgun trouble shooting" comes to mind.

At least it is not being done by a Yamaha mechanic charging a hundred bucks plus an hour for his time. Which has been known to happen.

[99yam40]

Rodbolt could you comment on the throttle movement?
Is it spring loaded so that it will go to idle if the fuse to the ETV blows?
If so how does that spring bypass the ETV motor to move it.
Just trying to understand how this ETV system works

[99yam40]

This has evolved into one of the strangest threads that I have read in quite a while.

The term "shotgun debugging or shotgun trouble shooting" comes to mind.

At least it is not being done by a Yamaha mechanic charging a hundred bucks plus an hour for his time. Which has been known to happen.

sad part is he said he has had it to several places and they all scratch the heads
having wrong stuff in a manual does not help things either

[pstephens46]

I have a headache.

[boscoe99]

sad part is he said he has had it to several places and they all scratch the heads
having wrong stuff in a manual does not help things either

Agreed. Frustrating to the owner and frustrating to the mechanic.

[boscoe99]

I have a headache.

That is a line for/from the wife.

[99yam40]

Boscoe, how about you can you explain how the ETV closes back off when that fuse blows and the ETV motor cannot run it back down to idle ?