Dual Engine System Switch

[Kirk Gibson]

Noticed this on the YDS yesterday, both engines said switch was off. What does this switch do? (Dual Engine System Switch)

[rodbolt17]

that's the module, that if rigged correctly with twins, resides behind the keyswitch assy.
it allows one engines warning system to control both engines RPM limit function.

[Kirk Gibson]

OK

Oh, OK Thanks for the information.
I guess since both engines show the switch off that mine must not be rigged for it.
What are the benefits of having both engines RPMs limited due to trouble on one engine?
Thanks Rodbolt

[rodbolt17]

yours is most likkly rigged for it.

it only shows on at an alarm/rpm reduction condition.
if your alarm self tests at each key on, it has it.

[boscoe99]

Oh, OK Thanks for the information.
I guess since both engines show the switch off that mine must not be rigged for it.
What are the benefits of having both engines RPMs limited due to trouble on one engine?
Thanks Rodbolt

One thing that I can think of would be is that it is not good to run a twin powered boat on just one engine. The one good engine would then be severely over propped and damage to the motor could occur.

Yours key switch will have it. It is just not being activated given that neither motor has trouble putting it into RPM reduction mode.

[Kirk Gibson]

Thanks

Oh, OK so it will probably go into that mode if something happens. Thanks thats good to know so I wouldn't think BOTH have a problem.
I would think that is something they should have told me in the owners manual but I didn't see anything about it there or couldn't find anything on a net search either.
Thanks guys

[boscoe99]

Yamaha is notorious for putting loads of crap in their owner's manuals (rule of the road for navigation for instance) that have little to do with a particular outboard motor but then yet fail to include important information applicable to the motor itself.

Them japs can do some crazy stuff. Great craftsmanship but crappy, crappy data.

On a somewhat related but non-outboard/non-Yamaha issue, I have been reading where the Japanese want to get more into the commercial and military aviation arena, selling products internationally. However, they have been stymied by their lack of understanding that if they don't have good data, folks that are truly in the know will not buy their products, however good those products might be.