XJ900 Over revolution switch

Hi,
I'm looking at an XJ900 TCI which has an extra input, compared to the XJ750, on the Yellow/Black wire which is an 'over revolution switch'.

In the wiring diagragm of the yamaha XJ900RK service manual it looks like a reed switch which goes to earth(negative). "looks like" being the operative two words.

I'm interested in seeing if anyone has a picture of the XJ900 dash innards or a working knowledge of the over revolution circuit as it must be associated to the tachometer circuitry closely.

Thanks!

 

What colour is the wire going in? I've got an RK dash (3 gauge) in bits at home

 

Hi Alive,
The wire according to the schematic is Yellow/Black all the way from the TCI right to the switch. (Yellow with a Black stripe)

 

I get home from work in about 5 hours, then by the time we do dinner and put the kids down... I'll do my best to get photos done tonight... So another 7 or 8 hours... Unless someone else is closer

Cheers

 

Interesting, must be a rev limiter switch on the tach somehow.

 

But the tach is electronic - - what would a reed switch pick-up on ??

And would the USA bike have this??

 

Ok here we go

Photo 1... Plugs.. Note the yellow and black is on a seperate plug


All yellow is yellow and black... See red arrows, wire goes thru plastic

[

This is what the tacho, fuel gauge and clock look like from the top down


Note the 3 wires going to the tacho... no yellow


Now it starts getting interesting... Yellow arrow points to the back of the clock, blue to the back of the fuel gauge and red where the yellow wire is atached to the board


And lastly... Red arrows show where the copper connected to the yellow wire run


Sorry dude, that's the best I can do

 

Hi Alive,
Thanks a lot for going to all that trouble, definitely above and beyond!
I now know one thing... and that is that I will need an XJ900 dash if I really want to have 'over revolution protection' and so... alas... it's disconnection for that poor circuit!

Now, I KNOW this is gonna make some one laugh so... wouldn't it be funny if over revolution mean't when your wheel stand started going a little bit too far. Now that would be a safety circuit!

Thanks again for the pics!

 

Great pictures. Looks like the line from the yellow wire runs to the small DIP relay that's next to TR1 and TR2 (upper right of your last photo).

To make this work with a non-900 tach would be hokey... you'd have to do something like add a pin that the tach needle could brush against at 9500 indicated RPM in order to trigger it.