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[J.D.]

Ok coronavirus boredom setting in.

Noted on some late model Buell carbs they used what appears to be some sort of electric choke and not the typical manual cable.

Anyone know how this works?  I'm guessing it's tied to the computer and using an engine temperature sensor of some sort as an input.  Would be cool to retrofit to a Harley.

[Twolanerider]

I've seen this.  Don't know a lot and only around the bike it was on once.  But here's what little I do know. 

The Buell carb was a CV40.  It wasn't an automatic choke but an automatic enrichener; just like the enrichener on the Harley CV carbs.  It's two wires and, apparently, just heats up like an old electric automatic choke would. 

I say "apparently" only because I saw this on a Sporty once.  Owner had just taken a switched power source to the carb.  So turn on the switch and the system starts heating up.  The owner of the bike said it worked fine.  I don't know anything more than that though.  Also only have the owner's word for his efforts as never actually rode the bike.  Did see it installed though and it wasn't at the guy's house.  He'd ridden 40 miles to get where he was that day.

[J.D.]

Yeah, I use "choke" and "enrichener" interchangeably (knob does in fact say "choke") and most everyone else does as well.  Wasn't sure if the Buell unit was just a simple heater or controlled by the computer.  Would be easy enough to wire and kinda cool to have a choke switch and not a cable.

[Twolanerider]

Yeah, I use "choke" and "enrichener" interchangeably (knob does in fact say "choke") and most everyone else does as well.  Wasn't sure if the Buell unit was just a simple heater or controlled by the computer.  Would be easy enough to wire and kinda cool to have a choke switch and not a cable.

Wish I knew more (sorry).  I do remember seeing that it was just two wires to it.  The bike I saw it on (I think this is right) did not have it switched.  It was powered all the time main power was on.  So apparently it's cold position is more choke/rich and it heats up to lean things out. All a guess of course. 

Also made me curious.  May have to go to Ebay and try to find a cheap Buell CV carb just to take it apart and take power to the enrichener just to see how it work for sure.

When it's working right the stock parts work fine.  An automatic choke would still be interesting though, if for no other reason than that no one else (mostly) has one.  Hmmm.... wonder if I should fart with the old FXR?

[J.D.]

I was thinking exactly the same, just find one on eBay.  I suppose looking at the Buell wiring schematic might offer some good clues.  Could have some sort of variable voltage feed tied somehow to engine temp if it is truly automatic (or would be a bitch to restart when the engine is hot).

Related... I've seen some Buell carbs with what appears to be some sort of sensor on the throttle (butterfly) shaft.  I assume this feeds a signal of some sort back to the computer.

[J.D.]

I wonder if instead of just a switch you could wire in a potentiometer/rheostat as a voltage divider/controller to dial up the exact amount of choke and adjust just like a cable (except with a dial).  Hmmm...

[Twolanerider]

All this social distancing leads to eccentric ideas and enough time to consider them.  All this Coronadowntime could get expensive.