Theory of operation

[jackmanjls]

I'm looking for a course/book that gets into the detail of operation of the Yama outboard motor.

Any suggestions?

[pstephens46]

You might need to be more specific. Or less specific.

How does a 4 stroke or 2 stroke motor operate?

[jackmanjls]

Mainly interested in how ECU plays with the various components, ie, DIS ignition, VST/injectors, temp sensor, timing, pulser coil, etc.

Hope that gives you a better idea.

[boscoe99]

Send me a PM with your email address and I will send you some literature.

If you could narrow your request down to a specific model that would help. There are many many different models and they might all function just a bit different in some respects.

[oldmako69]

But, but...I thought all this was "simple"??

[pstephens46]

But, but...I thought all this was "simple"??

Very simple unless you have an HPDI or a gd F225...
Forgot the smiley face...you know what I mean!

[pstephens46]

very simple unless you have an hpdi or a gd f225...
Forgot the smiley face...you know what i mean!

...........

:d

[rodbolt17]

suck.
squeeze.
bang.
blow.
been that way since the late 1800's.
once you realize that, the rest just helps it go.
does not matter in an articulated rod internal combustion engine.
all the ECU is ????? it is a simple truth table.
it has no smarts.
it is rather stupid.
it takes A B C inputs and outputs X Y Z.
yep.
it is that simple.

[dray0151]

suck.
squeeze.
bang.
blow.
been that way since the late 1800's.
once you realize that, the rest just helps it go.
does not matter in an articulated rod internal combustion engine.
all the ECU is ????? it is a simple truth table.
it has no smarts.
it is rather stupid.
it takes A B C inputs and outputs X Y Z.
yep.
it is that simple.

But But But Roscoe has the truth table!!!

[boscoe99]

It is one thing to have knowledge.

It is a completely different thing to be able to covey knowledge. Completely different skills.

Which is why we have doers and teachers. Both have a very valuable place in life.

Some doers just can't 'splain squat. Some teachers can't do squat.

The older I get the more embarrassed I am about how little I know and how little I can do. Life is humbling.

My sincere regrets to all of the teachers in that part of my life where I knew it all and closed my ears, eyes and mind to what they were taking the time to try and convey to me.

[dray0151]

"Which is why we have doers and teachers. Both have a very valuable place in life."

The truly rare person is the doer that has the patience to teach and to give that knowledge freely to others in detail after all the silly questions that we, (I) stupid people have.

I wish I could be such a rare person but I am not. I am simply a backyardian trying. I have and will continue to make many mistakes in my life and then ask why but have learned from each one of them.

[ausnoelm]

I am not too sure exactly what you want to know, but, in essence, it's not that complicated, a series of switches/sensors register set parameters, if any on these detect an out of range or open/close, the ECU then activates a light, an alarm or RPM reduction, or all of these, by applying a ground path, these parameters are checked via the known values in the service manual, you cannot cut open the ECU to do component level repairs (well, not easily at home) so, the correct measuring devices are required, if what comes in is good, what comes out is good, then that's about all you need to know. What each individual component does is sometimes very simple, and at times, very complicated, as in (say) an oil pressure "switch" lack of pressure simply activates the device, as distinct from a device that "feeds" a gauge, it varies the output according to oil pressure not simply on or off, it matters little whether it's a car or outboard, the devices are operationaly the same, you will need some pretty in depth electronic knowledge and experience to know "exactly" how the work, rather than just know they turn on and off.

[boscoe99]

I am not too sure exactly what you want to know, but, in essence, it's not that complicated, a series of switches/sensors register set parameters, if any on these detect an out of range or open/close, the ECU then activates a light, an alarm or RPM reduction, or all of these, by applying a ground path, these parameters are checked via the known values in the service manual, you cannot cut open the ECU to do component level repairs (well, not easily at home) so, the correct measuring devices are required, if what comes in is good, what comes out is good, then that's about all you need to know. What each individual component does is sometimes very simple, and at times, very complicated, as in (say) an oil pressure "switch" lack of pressure simply activates the device, as distinct from a device that "feeds" a gauge, it varies the output according to oil pressure not simply on or off, it matters little whether it's a car or outboard, the devices are operationaly the same, you will need some pretty in depth electronic knowledge and experience to know "exactly" how the work, rather than just know they turn on and off.

Sounds like what you are saying is that it is a stupidly simple speed density system.

[ausnoelm]

Maybe I am in a way, but after decades of component level repairs, I am pretty conversant with how almost every component works, and why, and also know that at times, why and how is not important, it's just the fact that a certain parameter needs to be applied, and it's not. All that said, I am not 100% sure if the OP what's to know why all the sensors are there, or how they work internally, when in fact, how they work internally matters little, just their input and output is all you need to know. Why some are there can be pretty self explainatory, as in, guess what an "air temp sensor" does? Now if you want to know WHY the motor needs to know what temperature it is, then it's a whole different ball****

[ausnoelm]

suck.
squeeze.
bang.
blow.
been that way since the late 1800's.

I think I went out with a girl like that once.......