MPH starter relay fix Breva 1100

[egschade]

I bought one of these when I had a Breva. Still carry it in my kit as most bikes lost kick starters long ago and it also charges phones. Have even started cars with it (but you only if they're just weak, not totally dead). Dozens of them on Amazon or eBay.

[nwguy]

With my 08 Norge not being able to start since installing a new MotoBatt battery, I tested with a multimeter and found the following:





Numbers in right columns are volts, "sol" = solenoid. The 3.2 voltage drop in yellow isn't good. I wanted to measure from the solenoid's spade terminal ("s" term) to the battery pos terminal, but haven't yet. Need to add a test lead onto the spade connector.

I charged up the old Yuasa battery (YTX20CH-BS) and swapped batteries. It fired right up. Called Battery Mart and got an exchange approved for that Yausa which is slightly cheaper so will get a refund.

Also bought a new Bosch starter from Harpers in MO. Will take a look at the old one until the new one arrives. Have been cleaning wiring terminals.

[Kiwi_Roy]

With my 08 Norge not being able to start since installing a new MotoBatt battery, I tested with a multimeter and found the following:





Numbers in right columns are volts, "sol" = solenoid. The 3.2 voltage drop in yellow isn't good. I wanted to measure from the solenoid's spade terminal ("s" term) to the battery pos terminal, but haven't yet. Need to add a test lead onto the spade connector.

I charged up the old Yuasa battery (YTX20CH-BS) and swapped batteries. It fired right up. Called Battery Mart and got an exchange approved for that Yausa which is slightly cheaper so will get a refund.

Also bought a new Bosch starter from Harpers in MO. Will take a look at the old one until the new one arrives. Have been cleaning wiring terminals.
You are obviously familiar with electrical tools so I say don't waste your money on the MPH fix, roll your own bypass but please upgrade the other wire from relay to solenoid as well, it passes 40+ amps for a split second while the second coil is energized.

I think you are saying the yellow wire is 3.8 Volts Low while starting, most of that Voltage drop is in the ignition switch. The whole point of bypassing the switch with a direct feed is to eliminate the Voltage drop and provide the solenoid with the energy it deserves.
There will also be considerable Voltage drop from the relay to the solenoid, that wire is woefully undersize for the current it carries, 40+ Amps while the solenoid is stroking, change that for a 16 Gauge. Just clip it a few inches from the relay and splice on the larger wire.
It seems you are familiar with electrical tools, don't waste your money on a tailor-made fix, roll your own.
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If you are worried about the battery OR the starter test it by running a new wire from the solenoid spade connector and touching it on the battery that will show you how it's supposed to crank.
Make sure you have the bike in Neutral and pull the clutch for safety, leave the key off you are just testing it for cranking.
Note: Fixing Startus Interuptus doesn't make the starter crank harder, it just makes it engage properly so it can start to crank.
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Every now and then Guzzi forget to wire in Startus Interuptus and wire the direct starter feed for example a 2001 VII Sport or the 2 Valve Griso but they always skimp on the wire from relay to solenoid.
My Griso engages the starter 3x as fast with that wire upgraded.

[nwguy]

I was saying with the multimeter's positive test lead connected to the starter case and the multimeter's negative lead connected to the negative battery terminal, there's a 3.2 volt drop after turning the key and hearing the click noise. This when it wouldn't start with the MotoBatt battery.

So you're saying I should replace the wire going from the spade terminal on the solenoid to the starter relay with at least a 16 gauge wire, correct? Do you know what color that wire is, or how to identify it in the relay? Earlier you said "pin 5", how to you identify that? I guess you just leave the old wire in place and trim the loose ends, then run the new, bigger wire wherever it makes sense to.

In an earlier post you confirmed that I do have the MPH fix installed. I did switch the 15 amp fuse in it to a 20 amp fuse.

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If I did want to install a button under the seat to ensure starting, would one of the button's wires go to the spade terminal on the solenoid and the other go to the positive battery terminal? What gauge wire would you use for that? Would you put a fuse in it? If so, what rating and on what side of the button (battery or solenoid)?

[Kiwi_Roy]

I was saying with the multimeter's positive test lead connected to the starter case and the multimeter's negative lead connected to the negative battery terminal, there's a 3.2 volt drop after turning the key and hearing the click noise. This when it wouldn't start with the MotoBatt battery.

 
If I did want to install a button under the seat to ensure starting, would one of the button's wires go to the spade terminal on the solenoid and the other go to the positive battery terminal? What gauge wire would you use for that? Would you put a fuse in it? If so, what rating and on what side of the button (battery or solenoid)?

Sorry I misunderstood.
If you get a Voltage difference from the starter case to the battery negative that's pointing out that you have a bad ground, the way they often connect to the gearbox behind the starter is not the best
it can get a oxide layer. Scrape the connection point and apply some grease there to keep oxygen away. You could also perhaps run another jumper to the starter bolt or one of the 6mm gearbox bolts.

I always use Vaseline on any connections especially the battery terminals, it's possible to see the full 12 Volts lost across the oxide layer between a lug and terminal.
The MPH fix does nothing to address the undersize wire from the relay to the solenoid.I think the contacts have larger terminals one wire is yellow, I think the other is Orange/Green
The other pair of relay terminals will be the coil, you can measure that with your meter somewhere around 100 Ohms I'm guessing.
Just cut them a couple of inches away and extend it with a larger cable.
https://www.thisoldtractor.com/guzzi007/schematics/2007_Norge.gif

To install a button it's really in parallel with the relay contact so it could run to the relay contacts as well then it would be fused by the MPH fuse. But here's the problem, the relay contact is rated about 100 Amps inrush, most buttons would fry if you tried to pass
more than a few amps. You should be able to connect the button to the short wires in the MPH fix so you don't have to break into the loom.
On my Griso when I replaced the Orange/Green wire I left it a bit long so it passes by the battery, I have a bare spot covered by heat shrink so I can touch it on the terminal.
I have used this twice, both times I fell over at zero speed and the tipover switch prevented it re-starting, cranking the starter must shake it back into contact.
It's also handy being able to spin the engine without the injectors firing e.g. while testing compression or establishing pressure after an oil change.

[Kiwi_Roy]

Alternate Start Button/Relay
If you look at the schematic I attached you will see it shows the start relay (3) has 12 Volts on one end of the coil pin 1 fed from the Injection Main Relay (29) via a Red/Black wire.
Pin 2 of the Start Relay goes to terminal 1 of the ECU, if everything is OK for a start the ECU grounds it's pin 1 causing the Start relay to energise, you could wire a small button between the relay pin 2 and chassis
that would crank the bike. Again I would tap into the short wire provided by MPH, any small Normally Open button would do there, the coil current is only about 100 milliamps.
How long before you accidentally try to start with the bike in gear?
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Remember pin 3 of the Start relay on your bike is powered directly from the battery via the MPH fuse. Just for kicks trace the old yellow wire back to its source, see if you can spot the cause of "Startus Interuptus"
Look at relay (29). what's special about it?
Why does that have special significance when using a Motobat battery?

[nwguy]

Yesterday I replaced the wire from the spade terminal at the starter to the pin on the starter relay. I just did a continuity test to determine which wire it was on the relay before cutting the wire by the spade terminal fitting. For me it was the yellow/orange wire. I ran a heavier gauge wire to both spades, soldered them on the spades and used heat shrink. On the solenoid spade I soldered an additional wire on it and ran it up to where the battery was and terminated it with a wire nut. Guess I'll forgo installing a push button since I can just touch the wire to the pos battery terminal to start it if need be. I probably didn't need to order a new Bosch starter and Yasua battery since I went on a ride yesterday with about 4 stops that required starting the bike, and it started right up each time. I'm still going to install the new starter and battery though just for piece of mind. Thanks very much for your help with this!