A/R VACUUM SWITCHES

[fallenmikethebike]

O/K question here for the fellow A/R owners , you have by now probably realised that big H threw everything in the pot when brewing the final chapter of it's 2T Trail bike .The tick over arrangement would appear to be the most complicated and fiendishly over engineered solution to a simple screw as is imaginable.
This switch seems to control a vacuum pull rod that in turn raises and lowers the throttle stop.



Close inspection of it in operation with the engine running seems to show that it should , through the push / pull ,rod keep the throttle stop lever pulled up tight against the idle screw , [ i think ] .
What appears to be happening is that the switch is cutting in and out , this in turn then sets the engine into a increasing and decreasing RPM cycle , that by holding the plate against the idle screw end , you can reset for a short while till it starts again .
Has anyone replaced these switches , [there are two in total ] ?Are they a Honda part only ?
What is the replacement cost of them .
It is possible to hear them "clicking" in operation . Do they receive their instruction to open or close from the PGM box of tricks ?
Regards Mike

[raveydavey]

Hi Mike

You're delving deeper than I've dared (or had time) to go. So;

1. No I haven't replaced either of them.
2. Don't know about Honda only part - If they're made by Denso, perhaps they're available elsewhere (couldn't read the numbers on the photo so couldn't do an internet search).
3. If they "click" then persumably there's a servo/relay that operates the rod/diaphram? The LT wiring diagram shows 2 wires to each. One is a common from the kill switch (black/white I think), the other wire per vacuum switch does indeed come from the black (Pandora's) box of tricks.

I can't remember if they are both the same - if so, have you tried swapping them over? Isn't one directly connected to the idle/air screw?

Sorry I can't be of more help.

Cheers RD

[fallenmikethebike]

Unfortunately they are different in as much as one [ on top of air box ] has three ports [ one part vacuum and then full vacuum ] the other is a single port ie on or of . I tried rudimentary search that came up with no matches.
The numbers i think read --- 384600-3480 12v Denso .
Once i get the alternator back on and the bike running i will know more, but i don't think the switches /relays are the problem .
Regards Mike