Temp alarm, no oil level indication, 2010 115 2T V4

[rafaelnfernandes]

Hi guys,

My first post on the forum, but I read many threads here, pretty informative.

Long story short, I bought a used boat that came with a 2010 Yamaha 2 stroke 115hp V4. The previous owner replaced a old Johnson 90hp with the Yamaha, but than decided he needed a bigger boat, so, sold it to me with only 59 hours on the clock, for cheap...

BUT, and there is always a BUT, isn't it? whoever installed the Yamaha, did a terrible job on connecting the Gauges. RPM and speed worked, and the hour meter, and that was it... (I must clarify that mechanically the motor runs fine, it's just the information that is not displayed)

It came with 2 round gauges, Speed and Tach.

I managed to "fix" the trim level indicator (wire was not connected in the back of the gauge) and installed (and connected to the gauge) a sender on the fuel tank, so fuel indication is fine now..

I'm having trouble fixing 2 problems now (both on the Tach):

Temp alarm blinks all the time: No sound, just blinks, as long as there is power to the gauges, it blinks, no matter if the engine is running or not, nothing changes...

Nothing shows on oil level indication: There is simply no bars or alarms where, according to the manual, its supposed to be, no indication at all.

See the video on this link: Yamaha Gauges 2010 2 stroke 115hp v4 - YouTube
(the motor is not running at the time of the video, but apart from the RPM, nothing is different when it is)

I checked the 2 stroke oil system and it is running fine... It gets oil from the remote tank to the motor tank up to the mark. The emergency switch works (pumping oil). there is no water. Consumption is around 1 liter per 50-60 liter of gas... running WOT the level on motor tank is fine.

I don't have any way to check the temperature, but have no reason to believe it is overheating: the "alarm" blinks all the time, even when not running, so no useful indication there, there is water coming out of the outlet (warm, not hot or boiling), it runs just fine...

Unfortunately, because I'm far in the countryside of Brazil, I have no Yamaha dealers around, so, no help on that front. It would be a very costly trip. So I'm trying to fix it myself.

Any ideas on what (how?) to do now? I look at all the wiring diagrams I found online so far, but nothing seams to match exactly what I have there... with those diagrams and some trial and error I managed to put the fuel and trim sender to work. but now, it looks like everything that is supposed to be connected is connected... so.. I hit a wall...

I never got any audible alarm, except for one time that I tried to start the engine without the emergency strap "plugged in" (I'm not sure of the correct name of the thing, but is the coiled red cord to kill the motor if you fall overboard). So I know that the audible alarm works... (at least in this situation)

Thanks a lot if you read so far, and even more if you have any suggestion.

[boscoe99]

The tachometer has to be set to the two stroke position. And, to the two wire sender position. Has that been done? Per the video it looks to me like the tachometer is in the four stroke position. See the diagram below. Also attached is a typical layout drawing for a two stroke Yam with multifunction Yam gauges.

[rafaelnfernandes]

Boscoe99,

Thanks for the reply. It will take a few days until I have a chance to check, but I will post here when I do.

I'm pretty sure that the switches are in the correct position, I think I checked that while troubleshooting the Trim sender. But I will double check.

From the diagram you posted, I can isolate a few things that I don't have and I'm left with:



The RED square is a bit different as I have the side mounted RC, but I THINK it uses the same connections as the Diagram, just put together.

From other documentation I found online, I'm led to think the the wires on the blue square are the ones responsible for the Temp alarm and the oil level, is that correct?

I'm just looking for ways to further troubleshoot this in case the switches are set correctly.

[boscoe99]

The trim signal, low pressure signal and over temperature signals all come from the motor and go the tachometer via the connector you have circled.

The tachometer when set to the four stroke position does not display any bars. That is why I think you have it set to the 4 stroke position. When set to the two stroke position then three bars will normally be visible.

Here is the diagram with a 703 control box.

[rafaelnfernandes]

Awesome!

I guess I will be able to sort this mystery now.

Many thanks Boscoe99.

I know it is very bad for the forum when people don't come back to post the results, so I will definitely be back, it will just take a week or two until I have the time to play around with this.

[rodbolt17]

I have seen this way to many times.
from Yamaha the teach comes set to 4 stroke,12 pole and 2 wire trim.
installed out of the box on a two stroke and you get the issue you describe.

[rafaelnfernandes]

Guys,

Problems solved. Yeap, it was the switches...

They supposedly were in the correct position, but, I moved them around (on, off, on, off) and finally let them in the correct position again.... Voilą!

Thanks so much for the assistance.

[boscoe99]

Thanks for the feedback. Glad it worked out for you.