Yamaha 200 4 stroke problem

[rodbolt17]

one thing about assume.
break it down to 3 words and you have an assumption.
its also why I posted a quick easy test for mechanical binding once warm.

most likely its not but sometimes a warm engine requires more current than a cold one. however we have to define warm and cold.
cold assumes an industry standard of 68*F.
warm assumes the engine is at or near its normal operating temperature.

the mechanical force nessasary to turn the engine under the above parameters should be almost equal.

see how easy this is ?

a single strand of battery cable with no load will show battery voltage.
it would most likely burn in two if you tried to actually engage the starter.

remember voltage is simply a measure of electrical pressure, nothing more nothing less.

current is simply a measure of electron flow past a given point and measured in AMPs.

decrease the pressure and electron flow is reduced.
increase the pressure and electron flow increases.

now how can I increase or decrease this pressure to regulate flow??

I can add a resistor/resistance.

this resistance is going to show up as a voltage drop across the resistance.

wrap your brain around this concept: in a perfect world you could place one voltmeter lead at the + terminal and the other at the starter motor terminal and engage the starter and the reading would be 0V.
however the world isn't perfect and lugs,cables,solinoids all are going to have a resistance.

this will show up as a .5-.7V reading on the meter.
anything more would indicate excessive resistance and an associated LOSS of electron flow meaning the device wont work as designed.
same applies with the negative cable.

any unwanted resistance impedes electron flow,creates heat and drops a voltage across that spot.

like I say, see how easy this actually is???

[99yam40]

Something you did not mention, probably because you did not want to confuse the simple electrical theory, is that the starter motor needs to do a certain amount of work to turn the motor at the speed it is designed to with the designed voltage to it.


Most simple DC motors just turn slower with lower voltage, and faster with higher voltage.
AC motors will draw more amps when voltage is lowered to try to get up to the speed they were designed to run at.
starter motors are a different DC motor design, I cannot think of the name for it at this moment.
If you lower the voltage at the motor, it will draw more current to do that same amount of work. Volts X amps = watts(work)

Someone with the proper knowledge can probably comment on how I really screwed this explanation up

[Nautical]

I like the idea of torgue wrench when its hot.. its getting all the power it needs when cold ! ???

[rodbolt17]

this is not a shunt wound DC motor.
its a simple permanent magnent DC motor.
its ONLY thought is it would really like to turn faster.
its operating current and load are about the liminting factor.

goes back to simple electrical pressure.
at 12V it will draw about 300 amps give or take.
that means I have 12V of pressure pushing the electrons.
if I lower it to 10 volts of pressure I start drastically reducing the amount of current avalible to operate the device.however it will ATTEMPT to work.
however just as in a A/C motor, if you lower the voltage AND the current is not avalible it overheats and starts melting things.

I have seen battery cables melt off the battery and battery switch connections melt completely out of the housing due to the heat generated by that bad connection(excessively high resistance).

remember we are not discussing a DESIGNED voltage reduction, we are discussing a voltage loss due to a resistance outside the design paremeters.

if you don't belive it unhook the starter + lead.
splice in a piece of 10ga wire.
try to start the motor.
have a fire extinguisher handy.

what you did was introduce a choke point(high resistance) in the circuit.

even though just before you let the smoke out that piece of 10GA wire had basically 0 ohms resistance the AMOUNT of surface area for electron flow was insufficient and the heat generated by this high resistance to electron flow will actually melt it.

that's why there are big heat sinks in your high power stereo.
its also why there are heat sinks and fans in your laptop.

simply goes back to pressure,volts X current flow,AMPs doing the work measured in watts.

that's why they don't want you to operate the starter motor longer than 30 seconds.
it can generate enough heat to pop the magnents off the motor housing and melt the solder on the commutator and brushs.

amperage is the amount of electrons moving past a given point in one second.
who they got to count them is beyond me but its worked for over 100 years.