ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-20-2013, 05:41 AM   #46
More_Miles
über-n00b
 
More_Miles's Avatar
 
Joined: Aug 2009
Location: New Brunswick Canada
Oddometer: 312
Quote:
Will it run on 12VDC?
Not in it's current iteration. Although a VR and external connection are all it needs to make it do so.

Quote:
What does it cost?
$120 landed or so

Code:
How long does it last?
Dunno, we'll see. Seems like a good piece of kit from a build quality perspective

Code:
How sturdy is it?
Home shop use I would say. Also, while people take it with them on trips, I wouldn't. Then again, I can manage to disassemble a pair of vice grips in the on board tool kit.

Quote:
Originally Posted by Plaka View Post
I get that nice tune with something that cost less then $5, uses no electricity much less batteries, has an unlimited lifespan and is unbreakable.

I like my gizmos as much or more than the next guy. On this one, I figured out the simple approach not only delivers perfectly but it's the end of the road. Cannot be improved upon with compromising something...and I've given it considerable thought and I'm good enough to invent something better if it can be done. I've worked at breaking patents, I know the drill.
I too have built a $5 differential manometer. And it works. Like I said, when I first tried the device, I was in spec for balance. This tool (the Harmonizer) allowed me to fine tune things. And it allowed me to do it quickly. About two min from hook up to tear down and I was done. My normal process is to fire up the BAF, connect, start the bike, tweak, quickly hit the kill switch since I turned the screw in the wrong direction, wait for the manometer to settle down and the worst of the bubbles to float out, start up again, rinse and repeat. A good 20-30 min of non-expert level tinkering.

As I said, I like mine. Could I live without it? Sure. Were it to cack out tomorrow, would I pay the money again? Hell no, it's only six months old! Five years from now? I might think about it.
__________________
Larger than life and twice as ugly!
My photos: stewie.smugmug.com
More_Miles is offline   Reply With Quote
Old 04-20-2013, 08:03 AM   #47
bgoodsoil
Dare to be Stupid
 
bgoodsoil's Avatar
 
Joined: Jul 2008
Location: Washington, DC, USA
Oddometer: 4,419
Quote:
The way I see it, the demodulated wave form is whatever it is. It will be like a sine wave, but there's no reason to think it should be a perfect one
Are we still talking about airheads?

You know if you set the mixture somewhere around 3/4 out and sync the cables with your eyeballs it'll run just fine right? I've always set the stops using the shorting method since they're so easy to carry but I don't bother to do it with the cables. Always run fine, though not as smooth as a real sync, and given me over 40mpg doing that. (130 mains)

I've got a Harmonizer now and it's got my eyeballs beat but I think the difference between the various tuning methods has got to be pretty small. Certainly not large enough to matter on your average road-going bike. I've got a $5 manometer, used it many times, and it works fine too.

The harmonizer works a lot like the twinmax. I can't say whether one's better than the other in terms of syncing-accuracy but they're both very simple and fast. As a previous poster said, the big advantage is not having to get the $5 manometer back in balance. You can run one carb out of sync for a second to pull the manometer back to level rather than wait for it to settle but it's still an, albeit small, hassle that the electronics avoid.

I've only had the Harmonizer for a few months but I've used it on a friend's r65 and it worked very well. The r65 feels like a sewing machine after a good sync.

I can tell the difference between when I sync with a device and when I don't based on vibration and performance. It's noticeable but it's not a run-or-won't-run dealbreaker. I've never been able to definitely say that I've done a better job using shorting or manometer. Maybe a more sensitive rider would notice.

Of course, I ride a GS. We're slightly less nerdy than the rest of the BMW community I think sync methods are like oil. So few of us actually KNOW anything so there's no absolute answer--but there sure is a lot of arguing!

DISCLAIMER: I would like to apologize if I have offended anyone who staunchly supports a particular syncing method. Please, do not take your radical syncing views as an excuse for terrorism or violence.
__________________
'85 BMW r80G/S--Another G/S on the road--Central America on a Shoestring--Nova Scotia on a Shoestring--Never Leave a Man's Behind

Proud SmugMug User Support ADV: Don't give those cheap bums your discount code

bgoodsoil screwed with this post 04-20-2013 at 09:03 AM
bgoodsoil is offline   Reply With Quote
Old 04-20-2013, 12:17 PM   #48
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,939
Setting mixture screws is part of the carb tuning and balance operation. The 32mm CV carbs are used on various models from 1970 thru 1995. There are approximately 50 different models of the 32mm carb. Variations with in these different models specify different Main Jets, Needle Jets, Idle Jets and etc, etc, etc. (if you need this info it can be found in various parts micro fisch or in the Bing Manual) The idea is the jet sizes will vary depending on the vintage and size of the machine. Larger engines usually use bigger jets. There is also a setting in the carbs called the "clip position". This is the number of steps down from the top that the jet needle is set at. Most BMW carbs are set at clip position 2 or 3 a couple are set at 4 and none are set at 1. The clip position is an important part of the balance and function of the Bing carburetor on the Airhead motorcycle.

In tuning the CV carbs there is an external screw setting for the idle mixture. Often called an "air" screw by people that have experience with some other type of carburetor it is a fuel setting. This screw will provide more fuel in the mixture as it is turned out, less fuel as it is turned in. Normally this screw is turned in till a stumble is noticed and then turned out till another stumble is noticed then the screw is left half way between these two points. This is mixture. The Bing Manual gives an Idle Mix Setting for each model carb they build. This is a starting position and can be used to warm the bike up so that the Mixture can then be set. Idle Mix Settings in the Bing Manual vary from 0.5 to 1.5 turns of the mix screw. You need the setting for your model. They are not all the same.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 04-20-2013, 02:26 PM   #49
brocktoon
Gnarly Adventurer
 
brocktoon's Avatar
 
Joined: Feb 2012
Location: NorCal
Oddometer: 257
Quote:
Originally Posted by AntonLargiader View Post
It would have to work with pre-'81 bikes to be truly useful. I think that will be harder, but there's probably a way. Might have to paint the OT mark and get it optically.
I like this idea for my /5. Some reflective paint on the flywheel will allow you to use an IR sensor to measure RPMs cheaply and easily.
brocktoon is offline   Reply With Quote
Old 04-20-2013, 02:35 PM   #50
Rob Farmer
Beastly Adventurer
 
Rob Farmer's Avatar
 
Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 5,375
Quote:
Originally Posted by bgoodsoil View Post
Are we still talking about airheads?
It's Antons fault. He's gone all high tech
Rob Farmer is online now   Reply With Quote
Old 04-20-2013, 05:48 PM   #51
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,579
Quote:
Originally Posted by AntonLargiader View Post
I'll try to remember to look it up, but I think it's either an AC generator or what BMW calls a 2-wire HES. There's a short tooth that tells it where it is on the gear.



The way I see it, the demodulated wave form is whatever it is. It will be like a sine wave, but there's no reason to think it should be a perfect one. You should care about comparing demodulated L to demodulated R, not comparing either to a true sine wave. And it could be done graphically, to give the operator more information.

Otherwise, the demodulation stuff sounds about right.

I see this as something you could just hold up to the timing port. On the '81-on bikes you can see the flywheel teeth and the OT plate, so you can build a sensor plug that will 'see' them also. Hold it in the timing hole, tweak the carbs and you're done. No need to mess with the Bing screws or whatever port plugs that particular bike has.

It would have to work with pre-'81 bikes to be truly useful. I think that will be harder, but there's probably a way. Might have to paint the OT mark and get it optically.

Or, it could be that only reading the existing timing marks like OT/S/Z is enough. It's worth checking.
The bike has a tachometer built in: the ignition. pick up crank rotation with an inductive pickup on the spark plug wires. Alternately count every other pulse and the ones you didn't count the first time. Now you are alternatly looking at one side (say a 5 sec sample) and then the other.

Trick is just to tell which side you're looking at when. But it seems that's a problem anyway.
Plaka is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 11:51 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014