What do you think Causes Startus Interuptus?

[Kiwi_Roy]

I have my theory but perhaps I'm wrong, it's time we put this to bed.
The poll asks what is the current draw from the time you press the start button until the gear engages and the motor starts to wind over. We are not talking the current that the motor draws, just the piggyback solenoid.

Update:
        Some interesting discussion happening, I'm surprised how the Poll is going.

[oldbike54]

 Great topic Roy  Of course the idea of putting this to bed may be optimistic knowing this group 

 Dusty

[Huzo]

Great topic Roy  Of course the idea of putting this to bed may be optimistic knowing this group 

 Dusty

Touche' Dusty one. But jeez it's (almost always) fun.

[oldbike54]

Touche' Dusty one. But jeez it's (almost always) fun.

 Always fun , well sure 

 Dusty

[Chuck in Indiana]

Ok, I know for a fact that the fuse will blow, so I'll say more than 15.. probably more than 20. <shrug>

Didn't vote, though, because I'm.. as usual.. clueless. 

[atavar]

My educated swag is 40+ amps.  The lie to this answer is that the solenoid is an inductive device and the intrush current at activation will be huge.

[charlie b]

That would explain why my 30A relays don't last very long.

[pete roper]

Goblins!

[rodekyll]

The big current is the pull-in winding.  The hold-in doesn't need nearly so much.  So the surge through the switch or relay is probably in the 30-40-amp range with everything fresh, and could push 50amp as 'lectrical and mechanical resistance increase over time.  But that's just the pull-in, and it happens between the Ka- and the -thunk of starter engagement.  Hold-in power is minor.  It happens starting with -thunk and stopping when you release the button.

Most dashboard starter push-buttons are in the 10-20amp range.  Most toggles are in the 5-15-amp range.  I have a simple solenoid I'm using as a hood popper.  Its only job is to twitch and pull a cable.  I burned up a 10-amp push button assuming it didn't need a relay.

[Wayne Orwig]

Well, many years ago when I researched it on Bill's Norge, I measured all of the voltage drops, and inrush current, using an oscope and a shunt. The paper that I took notes on is long gone. If you do a search, you may find it here on Wildgoose. I did the math and figured the resistance of everything in the circuit.
The answer is complicated because the circuit resistance also limits it. In other words, it may not quit get to 20 amps of inrush with the factory wiring. But a direct wire may exceed 40.
And the resistance alone the way is everything. Connectors, small wires, and the wimpy 15 amp fuse even.
So I'll vote 30 to 40, but that could be skewed to be a different number.

[organfixsing]

If I recall correctly, the BREVA and most Moto Guzzis before it ran the wiring for the current to the solenoid through the Ignition Switch. The V7II does not do this and so should not have a Startus Interruptus problem. Look for bad/loose battery joints.

Cheers
Brian   

[Kev m]

If I recall correctly, the BREVA and most Moto Guzzis before it ran the wiring for the current to the solenoid through the Ignition Switch. The V7II does not do this and so should not have a Startus Interruptus problem. Look for bad/loose battery joints.

Cheers
Brian   

I can't say about the V7II.

But looking at the wiring diagrams for the B11 and the 1TB V7 both show a Starter RELAY that gets power from a fuse which receives the current through the Ignition Keyswitch when it is in the Run position.

That Starter RELAY then uses that power to pull the STARTER SOLENOID when the start RELAY circuit is activated.

Now the SOLENOID itself receives power directly from the battery, but only on the STARTER side of the circuit.

I can't imagine the V7II is any different.

[Dilliw]

Well, many years ago when I researched it on Bill's Norge, I measured all of the voltage drops, and inrush current, using an oscope and a shunt. The paper that I took notes on is long gone. If you do a search, you may find it here on Wildgoose. I did the math and figured the resistance of everything in the circuit.
The answer is complicated because the circuit resistance also limits it. In other words, it may not quit get to 20 amps of inrush with the factory wiring. But a direct wire may exceed 40.
And the resistance alone the way is everything. Connectors, small wires, and the wimpy 15 amp fuse even.
So I'll vote 30 to 40, but that could be skewed to be a different number.

An engineer's way of saying he has no clue 

And none of this takes into account that it only happens at the absolutely worst times.  For me that was when Wayne was on one side of the parking lot and I was on the other (in a panic pushing every button, switch, and deploying sidestand).  He comes over and the bike starts right up. 

Pete is right, it's just the wing eater making faces at William Shatner.

[donn]

That Starter RELAY then uses that power to pull the STARTER SOLENOID

Now the SOLENOID itself receives power directly from the battery

Which is it?  Solenoid powered by the switch circuit, or direct from the battery?

[Wayne Orwig]

Which is it?  Solenoid powered by the switch circuit, or direct from the battery?

The ones I have seen, the relay contact is no help as it is. The path was something like: 30 amp fuse, wimpy wiring, ignition switch, wimpy wiring, 15 amp fuse, relay contact, then wiring to the solenoid.
There was a relay, but the power feeding the relay contact was weak, so the relay was really no help. My fix has been to feed that relay contact directly from the 30 amp fused circuit. Basically: 30 amp fuse, relay contact, wiring to solenoid.

[Kev m]

Which is it?  Solenoid powered by the switch circuit, or direct from the battery?

The answer was there, but you deleted too much of the quote:

a Starter RELAY that gets power from a fuse which receives the current through the Ignition Keyswitch when it is in the Run position.

That Starter RELAY then uses that power to pull the STARTER SOLENOID when the start RELAY circuit is activated.

Now the SOLENOID itself receives power directly from the battery, but only on the STARTER side of the circuit.

It's both since the Solenoid has two different but related circuits and each of them get their power from a different source.

Power for the Activation Circuit of the starter Solenoid comes from the starter RELAY through the ignition keyswitch.

Power for the Starter Operation circuit of the starter Solenoid comes directly from the Battery through the large gauge cable.

See my explanation in the V7II won't start thread, post #31

http://wildguzzi.com/forum/index.php?topic=82948.msg1310584#msg1310584

[beetle]

Startus Interuptus is due to the fact there is 32 feet of wiring between the between the battery and the solenoid.   

[charlie b]

Kev, I think the issue is the same as it was on my T5.  The power went up to the ign switch, then to the relay.  The relay had a jumper from that line to feed the solenoid through the relay.  So the power to activate the solenoid went through that bird's nest of wiring.

The fix is to cut that jumper and wire a fused feed from the battery to the relay, then the solenoid sees full battery voltage.  In my case I also raised the size of the wire to 16ga.

[Wayne Orwig]

Startus Interuptus is due to the fact there is 32 feet of wiring between the between the battery and the solenoid.   

No, no, no, it is not a bit over 10........METERS.



 

[sign216]

I added "the fix" of the circuit that bypasses the starter switch to go right to the relay.  I saw a bump of 0.5 volt, max, to the solenoid, and decided it wasn't worth the complication.

It's possible that the switches on my '09 V7 hadn't yet degraded.  Perhaps when they age more the fix will be useful.

[Kev m]

It's possible that the switches on my '09 V7 hadn't yet degraded.  Perhaps when they age more the fix will be useful.

That's my personal SWAG on the non-CARC bikes.

Also, my SWAG includes that there may be a difference in the CARC circuit (perhaps in whatever computer control occurs of the circuit) which makes it show up sooner on those models.

But that's just a SWAG from observation of how much more common it is on newer CARCs and that computer control seems to be the difference in the circuit. But I realize correlation does not prove causation.

[donn]

It might be worthwhile to think for a moment about the two questions here - the one posed by the subject title, and the one posed by the poll.

• What do you think causes startus interruptus
• How much current does the starter solenoid draw to pull in?

Do they have anything to do with each other?

My '85 California II has suffered from this complaint for a long time, and here's why I doubt it really has anything to do with the solenoid draw in my case:  it happens fairly rarely under very specific conditions, where the solenoid is presumably drawing the same current as it did 30 years ago.

The wiring isn't quite the same as it was 30 years ago, sure, a little of the shine is off and voltage may have dropped some.  But it still seems like it would be fairly constant all day long.  Maybe the kicker is that I still have had the problem once or twice - after the re-wire.  The solenoid is connected to a wire straight from the battery, and it has been a major improvement but not a complete fix.

I believe the real problem is that the solenoid isn't reliably grounded.  I didn't make this up, I got it here some years back.  This happens after I ride a while, enough to get everything good and hot, and then stop for 10 minutes or so, enough to partly cool down.  Different rates of thermal contraction open up the ground connection to the starter or solenoid.  The hotter wire is necessary not because the solenoid is a burly current draw, but because the path needs to overcome that weak ground.

[Kev m]

My '85 California II has suffered from this complaint for a long time, and here's why I doubt it really has anything to do with the solenoid draw in my case:  it happens fairly rarely under very specific conditions, where the solenoid is presumably drawing the same current as it did 30 years ago.

But isn't that a bad presumption?

Doesn't the solenoid age too?

Not to mention, if it's a solenoid ground problem, doesn't that effect the amount of current it draws as well?

And corrosion from age acting as an insulation would play a part too no?

[Wayne Orwig]

Debate wiring all you want,  I have also seen solenoids that are too tight in the plunger and need cleaned/sanded off.

[Chuck in Indiana]

Debate wiring all you want,  I have also seen solenoids that are too tight in the plunger and need cleaned/sanded off.

Absolutely. It's common. Add a little corrosion, and it sticks. Sometimes. 

[donn]

Doesn't the solenoid age too?

Not to mention, if it's a solenoid ground problem, doesn't that effect the amount of current it draws as well?

And corrosion from age acting as an insulation would play a part too no?

To a sufficient approximation, it's the same age when it starts, as when it doesn't.

This is my point:  if it's a simple function of gradual deterioration over the years, then it wouldn't ever start.  But no, it's usually fine.

The conditions under which it doesn't start point to the cause, which is not gradual deterioration of anything.

Bear in mind I'm talking about one specific 30 year old California II, and there could be all kinds of different things going on in other Guzzis of various eras.  If you have one that regularly refuses to start, under all kinds of motor temperature conditions, then you're looking at something different than mine.

[ohiorider]

Absolutely. It's common. Add a little corrosion, and it sticks. Sometimes. 

Yep.  had it happen to the original Valeo starter on my R100GS.  With the starter motor removed, it was possible to hold the starter button while rapping the solenoid lightly with a small hammer.  After a couple of taps, the solenoid would free up, and she'd start. 

[Kiwi_Roy]

Yep.  had it happen to the original Valeo starter on my R100GS.  With the starter motor removed, it was possible to hold the starter button while rapping the solenoid lightly with a small hammer.  After a couple of taps, the solenoid would free up, and she'd start.

Could it have been a weak start signal, same result No?

[Kev m]

To a sufficient approximation, it's the same age when it starts, as when it doesn't.

This is my point:  if it's a simple function of gradual deterioration over the years, then it wouldn't ever start.  But no, it's usually fine.

The conditions under which it doesn't start point to the cause, which is not gradual deterioration of anything.

Bear in mind I'm talking about one specific 30 year old California II, and there could be all kinds of different things going on in other Guzzis of various eras.  If you have one that regularly refuses to start, under all kinds of motor temperature conditions, then you're looking at something different than mine.

Ah, I see what you're trying to say, but I still think you might be making bad assumptions.

The relative age of the solenoid may be the same one day to the very next, but it's NOT the same as it was 30 years ago and neither is most of the rest of the circuit. So that changes the equation. It makes it more likely that a borderline system might fail from a temporary condition like temperature or particular charge state of the battery on any given day.

[Kiwi_Roy]

To a sufficient approximation, it's the same age when it starts, as when it doesn't.
 

There is something else that changes between one start and the next, the circuit resistance, in particular the ignition switch, as the contacts get dirty no two closings result in the same resistance. It may only vary by a fraction of an Ohm but that's all it takes when you are trying to switch 40+ Amps, do the Math
Current/Resistance = Voltage drop