1998 115hp limp mode?

[Jason2tpa]

Awesome boscoe, thanks for taking the time. I'll be testing next trip to the boat. Cheers.

[Jason2tpa]

Some clarification needed boscoe, for an electrical novice like me. See the attachment. Thermoswitch has a black (B) and pink (P) wire that connect to gray/black (Gy/B) and black (B) wires, respectively. Once I disconnect these two connections to test the temp system, then which black wire do I connect to which pink wire on the engine side harness? When it comes to electronics, I want to be 100% on what I'm plugging into what. Hopefully the attachment allows you to describe with numbers and letters the proper connections. Thanks bud.

To test the over temperature system on 99% of all Yams simply disconnect the pink wire and the black wire connected to the thermoswitch. Then connect the black wire to the pink wire on the engine side harness and start the motor. Wait up to a minute or so. You should hear the horn. If you have certain Yamaha tachometers (or maybe lights on the motor or on the dash) the lights will illuminate or an icon will flash. So, with the horn you know there is a problem. With the light or icon you will know what the problem is related to.

[boscoe99]

There goes Yamaha. Changing wire colours across a connector. Why? Oh why? Did they run out of pink and had some gray wire with a black tracer available?

This is one reason why it is dangerous to generalize about Yamaha motors.

Anyhow, take the male bullet connector to the black wire and plug it into the female bullet connector to the gray wire with the black tracer.

[Jason2tpa]

I'm sure they, Yamaha, just wants to keep pros like you from getting too comfortable lol. Sweet picture, thanks. Looks incredibly simple. And just so I fully understand, plugging the thermoswitch's 2 wires into each other tricks the alarm, believing engine temp is running high?

There goes Yamaha. Changing wire colours across a connector. Why? Oh why? Did they run out of pink and had some gray wire with a black tracer available?

This is one reason why it is dangerous to generalize about Yamaha motors.

Anyhow, take the male bullet connector to the black wire and plug it into the female bullet connector to the gray wire with the black tracer.

[boscoe99]

The switch in the thermoswitch closes when it reaches a certain temperature. Jumpering the wires together is electrically the same as the switch closing. The ground from the block in the black wire gets over to the other wire. The engine does not know the difference.

[Jason2tpa]

Gotcha, you da man! Or atleast i assume you're a man. Either way, you da man.

The switch in the thermoswitch closes when it reaches a certain temperature. Jumpering the wires together is electrically the same as the switch closing. The ground from the block in the black wire gets over to the other wire. The engine does not know the difference.

[Apparition]

Well color me embarased! I asked the experts to diagnose a problem with a 2 stroke that turned out to be fuel related. I cleaned the carbs and it is running fine. Thank you all for all your help. It just did not make sense to me that it would rev in reverse but not run in forward. I am dragging the boat to Port St. Joe in two weeks so I am happy that I do not need to order parts. THANKS AGAIN!!

[Jason2tpa]

Great news, congrats!

[99yam40]

lots of people do not understand that more fuel is needed to produce more power

reverse and neutral do not load up a motor like in forward gear in the water pushing

[Apparition]

Yes. I thought pushing a transom would take more power. I kept getting side tracked because it would die at about the same rpm as the limiter.

[TownsendsFJR1300]

I asked the experts to diagnose a problem with a 2 stroke that turned out to be fuel related. I cleaned the carbs and it is running fine. THANKS AGAIN!!

Congrates! Glad its fixed!

The reverse thing screwed me up but it sounded like a carb issue (un-less it was a limp mode issue).

Now, use a good fuel stabilizer and Yamaha's RingFree (all the time) and you won't have to dive into the carbs again!!!!

Drain the bowls if its going to sit for more than a couple of months for additional preventive maintenance.

[rodbolt17]

but is that an overtemp SENSOR or an ovetemp SWITCH ??

[boscoe99]

but is that an overtemp SENSOR or an ovetemp SWITCH ??

It is a switch being used as a sensor. It senses the presence of too high a temperature and closes itself to notify the CDI of the problem. No operator involvement required.

Now the toggle switch to manually transfer oil is a switch and only a switch, given that operator involvement is needed to switch the circuit on.

That is all. Carry on.