So, my S2R800 got new old 750 cases with a different switch at the back of the cases.
What's the difference? Can they be modified to work with each other?
(Because it's not connected at the moment I have all sorts of issues: no green light, no start without pulling clutch and raising side stand)
I think the old (750 type) switch was single wire and the new (800) is a two wire switch.
I'm not certain, but you should be able to connect the power wire to the switch, and the ground to the chassis.
That's what I'd try.
Suggestions about how to establish which of the two harness wires I choose to connect the single positive 750 wire to? Try both and see which works? (I own a multimeter, but we're still strangers)
Quote from: stopintime on April 21, 2013, 10:31:35 AM
Suggestions about how to establish which of the two harness wires I choose to connect the single positive 750 wire to? Try both and see which works? (I own a multimeter, but we're still strangers)
Set your multi meter to 12V and turn on the key. The wire that registers voltage would connect to the switch.
Not so fast :P
One red probe from the meter to the two-pin harness connector?
The other, black, from the meter to where?
The bike sends constant positive, through the plus/single wire, to the switch?
Switch breaks that positive to activate the green light?
???
As easy to hold a wire between the single wire and check which of the two harness connector pins make the light go green? Short circuit danger?
Quote from: stopintime on April 21, 2013, 11:15:55 AM
Not so fast :P
One red probe from the meter to the two-pin harness connector?
The other, black, from the meter to where?
The bike sends constant positive, through the plus/single wire, to the switch?
Switch breaks that positive to activate the green light?
???
As easy to hold a wire between the single wire and check which of the two harness connector pins make the light go green? Short circuit danger?
Sorry...
Red probe to the wire harness and the black to a chassis ground.
Switch
makes the ground connection to complete the circuit. In this circuit the bulb prevents it form being a 'short circuit'.
The advantage to using the meter is it removes the possibility of short circuits and damage.
So, with the bike in neutral, ignition on, I find the pin that makes the meter show a reading (the other pin won't show a reading) The wire going to that 'live' pin connects to the switch - the other to engine/chassis ground. Correct?
Will the green light be activated through the testing procedure?
Quote from: stopintime on April 21, 2013, 01:07:52 PM
So, with the bike in neutral, ignition on, I find the pin that makes the meter show a reading (the other pin won't show a reading) The wire going to that 'live' pin connects to the switch - the other to engine/chassis ground. Correct?
Will the green light be activated through the testing procedure?
Correct...
unless the smoke gets out. ;D
Quote from: ducpainter on April 21, 2013, 03:07:41 PM
Correct...
unless the smoke gets out. ;D
[laugh]
too true
[bang] other way around - my 750 engine is the one with a dual wire switch and connector - my 800 harness has a single wire bullet connector.
Not sure, but you should be able to use the switch from your 800. I think the difference is the newer one grounds internaly to the case so a ground wire is not needed.
Quote from: howie on April 22, 2013, 03:50:06 PM
Not sure, but you should be able to use the switch from your 800. I think the difference is the newer one grounds internaly to the case so a ground wire is not needed.
Don't know how it looks inside, but the hole for the 800 switch is deep (before you get to the threads) where the 750 is not. Either the case thicknesses are very different or the switches are.
Confuses me a little more - the parts catalogs for M750i, S2R800 and SS750 all show the same switch (two wires)
The switch does need to be the correct length to work, which one would be the correct length for your now custom operation I don't know. As I remember Ducati went to the single wire switch around 2001. Too long can be spaced to work.
Another "don't know" - this donor engine had a 5 speed gear box, but now houses my 6 speed....
If the switch is two wire then just ground one of the wires and feed voltage from your harness to the other and see.
The smoke shouldn't escape.
If I choose the wrong wire, what's the result?
Quote from: stopintime on April 22, 2013, 06:22:55 PM
If I choose the wrong wire, what's the result?
You can use your multi meter set on ohms to figure it out.
The ground wire will have continuity to ground...0 ohms...in neutral.
The other conductor will only have continuity in gear.
You're fast for your age - lost me again...
My meter ohm switch has six levels: 20M, 2M, 200K, 20K, 2K/~ and 200/)))
One probe to random pin, other probe to ground. Whichever pin makes the meter go ZERO is going to be my ground, correct?
Quote from: stopintime on April 22, 2013, 06:38:02 PM
You're fast for your age - lost me again...
My meter ohm switch has six levels: 20M, 2M, 200K, 20K, 2K/~ and 200/)))
One probe to random pin, other probe to ground. Whichever pin makes the meter go ZERO is going to be my ground, correct?
I've had practice. ;D
The scale doesn't matter...continuity, or 0 resistance is. I'd probably use the 2K scale.
Yes...In neutral.
It doesn't matter, but I don't understand how anything will happen if there is no + into the switch...
Quote from: stopintime on April 22, 2013, 06:47:02 PM
It doesn't matter, but I don't understand how anything will happen if there is no + into the switch...
An ohm meter has a battery to provide a small voltage source to obtain readings.
You and I have the advantage of being on the dumb end of the meter. ;D
afaik.
the single wire switch earths thru the shift drum, and the drum has a strip of (going to have a look. back now) plastic or the like laid into it.
the two wire switches use a bump on the shift drum to push the end of the switch in to make contact. so you have the run the switch for the shift drum, not the cases.
i have a 6 speed 696 box i was going to try to fit to an early 750 (pre 98) and apart from a lot of cutting bits off i had considered how to make the late drum work with the old switch, basically coming up with a round headed something (rivet, etc) fixed to the drum.
if it is in one piece it may need to become many again. or start thinking outside the cases (punny, huh?).
How can it earth to the drum if there is plastic where it touches? (if I read you correctly)
Besides that, are you basically saying that I have to use my single wire switch and make a new location for it in the engine case? That's not a simple solution....
I could learn to live without a green light, but the side stand blocking any running and the clutch lever to be pulled before every start is problematic...
the plastic is not full circumference, so there is a short steel section, which corresponds to the switch at neutral. as i understand it anyway.
is the single wire switch too long or too short?
Judging only on how deep the single wire switch sits, I'd say it's too short.
half of it can be seen behind the spring:
(http://i329.photobucket.com/albums/l394/stopintime/bomb/bomb016.jpg)
Near as I can figure, you've got a contact-style shift drum in a plunger-style switch crankcase.
No way to fix it properly without splitting the cases, and even that might not be possible.
If you connect the neutral-switch wire from your harness to ground, it should allow the bike to start.
You will have a perpetual green light on the dash, and the ability to try to start it in gear.
Neutral Switches:
Upper is plunger-style, it's actually a switch.
Available in two-wire (as shown) and single wire for sure, perhaps more.
Lower is contact-style, which grounds the terminal to the shift drum.
Available in at least two nearly identical versions.
(http://farm9.staticflickr.com/8126/8675827461_dc4ca3c08f_b.jpg) (http://www.flickr.com/photos/79721557@N02/8675827461/)
Shift drums:
Upper is plunger style, lower is contact-style, you can see the plastic inlay.
(http://farm9.staticflickr.com/8381/8675827161_b58aa1629a_b.jpg) (http://www.flickr.com/photos/79721557@N02/8675827161/)
Closeup:
(http://farm9.staticflickr.com/8119/8676931632_5cca3c183d_b.jpg) (http://www.flickr.com/photos/79721557@N02/8676931632/)
Is it possible the new style switch might work since Lars still has the 6 speed?
Quote from: howie on April 23, 2013, 10:48:43 PM
Is it possible the new style switch might work since Lars still has the 6 speed?
The new sensor is a larger diameter, so it won't fit the old cases.
It *may* be possible to drill and tap old cases to fit the new sensor.
But not a good thing to do on an assembled motor.
There was a DP 6-speed kit available in the past, perhaps it had the plunger-style shift drum.
But that requires finding that "maybe" part and splitting the cases to install.
if the end of the plunger type sensor hits the drum fit it and cut one of the wires and solder it to the body of the switch. that way it will earth against the drum if the switch conducts.
which it won't thinking about it. cut it up and make it work using the body of the correct switch for the cases.
I will ground my harness' single wire - it works as described. Green light always on, must do blind searches for neutral and make sure I have found neutral before leaving it running on the side stand. Not ideal, but better than my current clutch switch dependency.
Later, I can see if the bike builder is able to relocate the stuff inside the single wire switch over to the dual wire switch. The depth is different (switches, drums and cases), so it might require some machining/drilling from the outside and/or new positioning of the stuff inside...
We'll see.
Thanks for your help so far - please comment again if you have more [thumbsup]
Since the new style switch is thinner than the old style switch a good machinist could make a threaded insert.
Quote from: howie on April 25, 2013, 12:01:36 AM
Since the new style switch is thinner than the old style switch a good machinist could make a threaded insert.
It's the other way around ;)
Doh [bang]
Quote from: stopintime on April 24, 2013, 11:10:01 AM
I will ground my harness' single wire - it works as described. Green light always on, must do blind searches for neutral and make sure I have found neutral before leaving it running on the side stand. Not ideal, but better than my current clutch switch dependency...
Back when dinosaurs walked the earth, dragons ruled the night and guys like me, Howie and DP were teenagers, neutral switches were not invented. Not much of a problem at all once you adapt to it. Requires that you pay attention, which is never a bad thing.
Quote from: Langanobob on April 28, 2013, 05:22:26 PM
Back when dinosaurs walked the earth, dragons ruled the night and guys like me, Howie and DP were teenagers, neutral switches were not invented. Not much of a problem at all once you adapt to it. Requires that you pay attention, which is never a bad thing.
Back before neutral lights you could also start your bike sidestand down, hand off the clutch too. I agree, not too much of a problem unless you need it to pass inspection.
You're all too young ;D
In my teenage years we only had kickstarters - problem solved [roll]
My engine guy will not sleep before he has found a solution,
but for now it's working ok.