MFI micro switch replacement- Does it require system adjustment?

[Haasman]

Found the MFI micro switch not functioning allowing a loud backfire on trailing throttle.

Tested the switch and found no difference between depressed and released postions, measured at the 2 electrical connectors.

About to replace the switch- Does it require system adjustment? Or can it simply be replaced?

[nickgreen]

I just replaced mine. Economy definitely improved,but I rather missed looking in the mirror as the scenery was lit up by a three foot flame!

[mobius911]

No adjustment needed, unless you monkeyed around with other settings to compensate for the lack of a working switch. By the way, I think there may be some tutorials somewhere on how to open the switch up and repair it, if you're so inclined. IIRC, there are some soldered connections that fail over time and are the most likely culprits.

Also, it shouldn't make any difference, but the way I've tested it is to rev to 2500-3,000 rpm, then push the plunger. If the rpms don't drop to idle then the switch is not working. You may want to make sure your tabs are making good contact at the connector as a first, simple check.

[Haasman]

Economy definitely improved,but I rather missed looking in the mirror as the scenery was lit up by a three foot flame!

Made me laugh! I can see it!

Thanks for the tips Jeff. I will go through your suggestions. No, havent messed with it. Been using this:

[mobius911]

Thanks for posting; hadn't seen that.

[edmayo]

After switch is installed back screw completely away from switch plunger, then turn screw against plunger until a click is heard, then 1 turn further, tighten lock nut.

[BOYER73S]

Ed

Why won't my screw reach the micro switch even at full adjustment, nothing looks to be bent?

What am I missing probably some dodgy adjustments in the throttle linkages I suspect

[Haasman]

Thanks Ed.

[Haasman]

Clyde- that would be my guess. Maybe compare you linkages to some others, close up pictures of the link lengths etc?

[72t4tom]

Boyer73S...which side of the of the linkage is the locking nut? I had to move mine to the switch side to get enough screw adjustment