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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: frankenduck on February 10, 2013, 08:14:55 AM

Title: Early K100 TBs: What are these parts? Purpose/function?
Post by: frankenduck on February 10, 2013, 08:14:55 AM

See attached.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: frogy on February 10, 2013, 08:30:25 AM

#11 looks to be a "one way valve", not sure about other piece.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: Inge K. on February 10, 2013, 08:36:32 AM

If I remember correctly this vacum switch would advance the timing a few degrees to improve fuel economy,
 but it probably did close to nothing....since it was discarded after a short time.
It grounds pin #15 at the ignition ECU.

Inge K.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: frankenduck on February 10, 2013, 09:49:59 AM

Thanks, Inge.

I figured since it had a switch that it's wires had to go somewhere.  Interesting that they didn't change the L-Jetronic when they got rid of it.  Probably just easier/cheaper to keep the same circuit design and leave it as an unused pin though.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: wmax351 on February 10, 2013, 05:43:41 PM

Inge is correct. It bumps the timing a bit at lower rpm, low load (high vacuum).

Do you know where it connects on the K75? I could use that to selectively bump the timing with the megasquirt system, without having to add full spark control.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: Inge K. on February 10, 2013, 05:58:15 PM

Quote from: wmax351 on February 10, 2013, 05:43:41 PM

Do you know where it connects on the K75?

Early K100's only.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: frankenduck on February 10, 2013, 06:04:08 PM

K75s never had it, only 85 and earlier K100s.  It grounds pin 15 on the ICU. You could try that on a K75 ICU and see what happens. :dunno2:  Might be interesting to open up the ICU and see if that pin's connected to anything.

Title: Re: Early K100 TBs: What are these parts? Purpose/function?
Post by: wmax351 on February 10, 2013, 08:49:03 PM

Quote from: frankenduck on February 10, 2013, 06:04:08 PM

K75s never had it, only 85 and earlier K100s.  It grounds pin 15 on the ICU. You could try that on a K75 ICU and see what happens. :dunno2:  Might be interesting to open up the ICU and see if that pin's connected to anything.

I might give that a go. I don't see why they would change much on the system.