So your Yamaha 701-760 won't start ( what to check before making a new thread)

[WFO Speedracer]

Unplug the stop switch, I know what you are going to ask, which wires, and where are they at, ok here goes the wires are a black and a white in the same connector, to find them follow the wiring coming from the handlebar till you reach the connectors and unplug the connector with the black and white wires .

On some skis specifically Waveventures and Waveraiders these connectors are hidden in a mess of clear plastic wiring loom wrap, unwind the wrap till you find the connector and unplug it.

Does it have spark, how do you know if it has spark, unscrew the spark plugs from the head put them in the spark plug caps and lay them on the head, hit the start button, to verify if you have spark or not. If you have spark now you have found your problem, repair or replace the start stop switch, if not continue on.

Time to open up the electric box, you know the black box full of spaghetti with 100 screws holding it together, yep that's the electrical box, once you get the 100 screws out you can make some electrical checks if you have a volt -ohm meter that is.

I don't usually mess with ohm checks just yet, what I am more interested in is AC voltage , specifically the voltage coming from the source coil and the pickup coil. you are looking for a about 4 to 5 volts from the pickup coil that would be the white/red and the black ground wire.

The source coil is a brown/white and the black ground wires, look for around 30V AC from the source coil. If both of those check out ok you need to check the output on the CDI box next, this will be the orange and black wires coming out of the CDI box and going to the ignition coil.

Unplug these two wires from the ignition coil and check AC voltage coming out of the CDI box .If you don't get voltage on these two wires when you crank the ski over and the stop switch is disconnected your CDI box is dead, replace it.

In order of most likely to fail :start stop switch, CDI box, source coil, pickup coil, ignition coil.

I just moved the thread here from PWCT so I wouldn't have to keep sending links to the other sire .

 

[WFO Speedracer]

I am going to make an addendum here :

The mortal enemies of any electronic components including batteries are heat and vibration , this is why most CDI boxes are remote mounted in plastic -Aluminum boxes not connected to the engine , the stator of course is always the exception to this rule and eventually years of heat and vibration take out the stator coils and they stop working.

This is also why on some sitdowns you will see cooling built into the stator cover , Kawasaki 1100's and some Seadoos like the RFI 787's have this built into the stator covers , stand up skis do not , standups also get jumped and generally knocked around a lot more than sitdowns do , those coils in the stator are just coils of a certain size magnet wire wrapped around the core so many times as to produce a certain resistance.

If you cared to you can unwind the coil , find the proper size of magnet wire , count the number of windings and rebuild the coils , at least on a 650 , 701 or 760 anyway, there is nothing magical going on in there , this is also why there is an ohm range that the coils must fall into , you can't get exact repeatable ohm readings on wound coils like that so there is some variance in the readings on them .

On the 1100 engine Yamaha in their infinite wisdom decided to mount everything inside a cover attached to the engine and even though the CDI on those is rubber mounted there were still a lot of CDI failures on those engines , I have replaced many of these over the years. I account most of the failures to heat and vibration from the engine even with the rubber mounting on the CDI .

 

[Big Kahuna]

Moved to Tech Faq.......... Thanks Terry.