How to test the pick up assembly

[dna9656]

P/N 26H-81670-10-00

Listed in the Parts Catalog under the Generator System though it is a part of the IGNITION system.

Located INSIDE the Starter Clutch/Fly Wheel/Generator (L/H side engine) cover.

Purpose: Sends signals to the Ignition for spark timing.

Should be approx. 100 ohms resistance.

The impulse from some coils are too weak for some after market ignitions (Ignitec) but the stock ignition (TCI) senses the weaker signals ok.

Anyone test these yet? If so what technique did you use?

[bongobobny]

Pretty much just an ohmmeter to check for proper coil resistance. To my knowledge they work fine with the Ignitech. Now, here's the klinker, sometimes these coils become thermally sensitive and the coil resistance changes drastically when heated. Not a very common problem but none the less not unheard of. What happens is bike runs fine when cool. The coil heats up and the insulation breaks down and partially shorts the coil, making the output lower, and the TCI looses timing, the bike won't run! Let it cool, the short goes away, and the bike runs great again until it gets heated up again!! This problem also happens with stators, ask Xv1100SE...

[dna9656]

Pretty much just an ohmmeter to check for proper coil resistance. To my knowledge they work fine with the Ignitech. Now, here's the klinker, sometimes these coils become thermally sensitive and the coil resistance changes drastically when heated. Not a very common problem but none the less not unheard of. What happens is bike runs fine when cool. The coil heats up and the insulation breaks down and partially shorts the coil, making the output lower, and the TCI looses timing, the bike won't run! Let it cool, the short goes away, and the bike runs great again until it gets heated up again!! This problem also happens with stators, ask Xv1100SE...

 

How woowd! (rude).

Yes I have heard of coils becoming thermally sensitive. Anthing with a winding (coil) can do this, runs fine till it gets warm. In my case the bike is stone cold. Dingy says that the coils may have a low output the TCI can see but the Ignitec can't. Also the 6 pin connector by the fuel pump/air ride selector (aft of rider's left knee) can be dirty or have bad contacts...

[bongobobny]

Well, by golly, if anybody would know, Gary would!! Myself I have not heard of this issue from anyone on the site, but that does not mean it does not exist! Yes, The connector you mentioned HAS caused issues in the past with lost pickup coil signal. That's the problem with 25+ year old bikes and electrical connectors in general...

 

The Yamaha TM lists the spec as 110 ohm plus or minus 10% at 68 degrees F. Sorry, I quit working 4 years ago so I don't have easy access to the temperature conversion charts but as you probably already know resistance goes up with temperature. If you measure the resistance at the TCI connector it should give you a relative indication of the condition of the connector you are referring to.

 

Other than that you would have to use an oscilloscope to dynamically test the output at the TCI. Are you having an issue with your Ignitec unit???