The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Justin B. on August 08, 2009, 10:35:43 PM

Title: Some random thoughts about needed stuff
Post by: Justin B. on August 08, 2009, 10:35:43 PM
I sometimes think too much, lately has been one of these spells.  I've ordered some parts to experiment with and was hoping to get some input.

Project 1 - I have realized that the wiring harness down to the oil pressure switch and neutral switch on every used Airhead I've bought (except for my '95) has extremely brittle/cracking insulation and the connectors are often quite brittle as well.  I propose to make a replacement with two new connectors.  One connector would be supplied as a shell and two "crimpable" pins so no wire cutting/splicing would be required.

The Twinmax carb syncher seems to be very popular and generally has good reviews.  I was going to get one until I found most places selling these just shy of a hundred dollar bill.  I started thinking (again) that most Airheads worth their salt have a DMM and maybe a little box they could plug their DMM and a couple of vacuum lines into might be a welcome item in the toolbox.  I have ordered a couple different differential pressure transducers, op-amps, and precision resistors and will breadboard one up and then see how much a "kit" of parts might cost if somebody wanted to brew one up.

Ok, I feel better now that I've got that off my chest and hopefully'll be able to sleep...
Title: Re: Some random thoughts about needed stuff
Post by: Motu on August 09, 2009, 04:56:39 AM
Years ago I made a vacuum probe for my Fluke 98 Scopemeter - out of a GM MAP sensor (Holden Commodore) a couple of pots to adjust input and output and a battery pack.It allows me to see intake pulses as a wave form on the scope...a pretty powerful diagnostic tool.

I have used it on a bike to set the carbs (XLV750)...but you would need two to compare,it gives no value,just the wave form.But I could save,and superimpose over the original to compare.But an airhead is so easy to work on I've never bothered with anything fancy in setting the carbs.Piece of vacuum hose in the earhole is good enough.
Title: Re: Some random thoughts about needed stuff
Post by: Barry on August 09, 2009, 02:08:11 PM
A normal U tube manometer does just fine in the garage but I have often thought it would useful to measure carb balance while riding when the engine is under load to see if any variations correspond with vibration periods.  Can't imagine riding around with a yardstick manometer lashed to the bike. A DVM lashed to the tank might just work though.

Would you have a Delta P on each carb or  one sensitive enough to measure the difference  between carbs.
Title: Re: Some random thoughts about needed stuff
Post by: Justin B. on August 09, 2009, 02:38:37 PM
I ordered 2 different transducers with different max pressures and sensitivities.  We'll see what happens...
Title: Re: Some random thoughts about needed stuff
Post by: weasel01 on August 09, 2009, 09:17:12 PM
Hey Justin, that sounds like a very cool project ...I too have been thinking about a similar idea.

Since I'm an audio electronics guy I thought about using the vacuum to
trigger a pitch or tone that could then be read on a guitar style tuner and literally "tune" the carbs....just a thought.
Title: Re: Some random thoughts about needed stuff
Post by: Justin B. on August 09, 2009, 09:52:05 PM
My, how "artsy"!  ;)  I've got one of those clip-on chromatic guitar tuners, it even did a real good job when I used it when tuning my old piano for the first time...
Title: Re: Some random thoughts about needed stuff
Post by: weasel01 on August 09, 2009, 10:10:04 PM
Artsy? maybe but with purpose. a cheap electronic guitar tuner tracks sooo much more quicky and accurately than a cheap dmm...

Just seemed like a nice idea at least.
Title: Re: Some random thoughts about needed stuff
Post by: ambrose78 on August 16, 2009, 08:15:47 PM
Any progress with the 'tuning' devices?
Title: Re: Some random thoughts about needed stuff
Post by: weasel01 on August 16, 2009, 08:57:55 PM
Yes he got the parts but moved the thread down to the misc. tech page.
Title: Re: Some random thoughts about needed stuff
Post by: ambrose78 on August 16, 2009, 10:06:38 PM
ah ha. A bit of a segway there.