Final Startus solution?

Hello all,

I've been reading with great interest about the starter circuit occasionally blowing fuses but I have not gleaned which model years were affected or what the actual cause/solution was? I'm guessing inadequate wiring to the solenoid but there may be more to it.
A YouTuber in Aukland NZ has an '11 or '12 GRiSO that was having the problem and his local dealer corrected it.
He never said what the problem was and I wrote to the dealer to get their answer and got no reply.

Has this finally been resolved?
According to my 2011's prior owner he never blew any fuses. I'm wondering why not.

It can happen to any Guzzi. There's no certainty that it will, nor any guarantee it won't. I never had a problem, but I preemptively 'fixed' mine with the MPH kit. You can DIY, but the kit is cheap, well made and install takes a couple of minutes.

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Note: I have no interest or relationship with MPH Cycles

Thanks Mike.

I was thinking of my own preemptive fix but this MPH kit is 'one stop shopping'
What problem is it actually fixing? Undersized wire, better contacts, etc?

It's Mark.

The starter solenoid electrons takes a circuitous route (pun intended) hither & yon through the control switches, visiting the lights and other things. Unnecessarily. Consequently, voltage drop and connector resistance can cause issues. Connecting the solenoid +12V directly to the relay fixes it.

So sorry. I meant Mark and didn't realize I wrote Mike.

That explains it.
The MPH fix sounds sort of like what I would have done.
Good to know. thanks

Kind of disgusting they haven't remedied that problem over the years.
Really no excuse but there ya go. At least it can be corrected without too much fuss.

No excuse, you say? It's a GUZZI!

I know it's all part of the charm but it seems to me if they wanted to sell more bikes they'd build in a little less 'charm' and a little more dependability.It's not rocket science. It's basic automotive electrical design. It kind of reminds me of the old brit bikes that were known for leaking oil. They're fine now I'm told but it had to have hurt sales over the years.
At least the fuse problem is a known issue that can be easily remedied.
After I make the mod my Tenni will be even cooler.
It will have rollers by mid October too.

Thanks for the insight on the cause and fix.

I have made it something of a mission to solve the Startus Interrupts problem, there is no one answer, it depends a lot on what model you are talking about, almost all Guzzi models have suffered since the late 80s.
The solenoids that engage the starter gear draw a lot of current, 40 to 45 Amps to draw the gear into mesh before the motor even starts to turn.

The problem is for one reason or another the starter solenoid is strangled by poor wiring.

The earlier CARC bikes like my 07 were wired correctly direct from the battery to the start relay via a fuse however the wire from the relay to solenoid is woefully under size starving the solenoid of the current it loves.
Just by increasing the wire a size my solenoid now works 3 x as fast

The later CARC bikes have a fatter wire between the solenoid and the starter but now they feed it via the ignition switch, i doubt the switch was ever designed to pass 40 Amps, the contact resistance added to the wire resistance adds up so once again the solenoid finds itself starved of electrons.

Is it any wonder the factory don't understand the starter if it's not drawn correctly, they leave out all together the most important high current coil that does all the grunt work and just show the one that draws 10 Amps, it's just a holding coil.

The MPH fix is a good stopgap for those reluctant to cut into the loom, it basically takes the load off the ignition switch and puts it directly on the battery same as the earlier model, It would have helped mine also because the wire is fatter.


Another thing that will starve the solenoid is a loose spade connector, Wardest suggested using a connector designed for an electric range element, I haven't checked one out but it stands to reason they must be a better connector to stand the heat. Apply something to stop the contact corroding as well in that wet location, I use Vaseline for that but any form of grease will be preferable to leaving it dry.
Grease doesn't conduct electricity, it just stops the corrosion which hampers current flow.




Here's a very simple sketch of a solenoid, compare it to any of the Guzzi schematics and you won't find the coil to the right of the solenoid.
thats the one that does the lions share of the work, it's only active for a few milliseconds but the starter is dead in the water without it.
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If you have any doubt about what I am saying I encourage you to take your multimeter and measure the resistance from the spade lug on the solenoid coil to chassis
then you can calculate how many Amps it will draw by Ohms Law, just divide 12 by your resistance.
The more we discuss this the sooner we will put it to bed.

As they say at Nike - Just do it!

Yes you can clutch start them, yes you can jumper cable them, yes you can fix "startus interruptus" - just do it. 'Talian 'Lectrics -, yes, part of the "character"

Thanks for the drawing. I see what you mean.
I was actually going to disconnect the battery from the starter motor and put my ammeter in the solenoid coil circuit to measure the current when 'starting' without engaging the starter motor. Then go from there.
I don't think the solenoid should draw more current with the starter engaging but it's worth checking both scenarios.
I need to learn how to attach drawings to these posts.

I'm still in shock over how much current is in those switches and little wires.

I just realized I implied the MPH was barely adequate.
That wasn't my intention.

Hi all,
got the starter clunk /click on my breva 1100 at the weekend.
did the mod that is well documented on most forums .
worked spot on.
rode the bike 1st time today and have no rear light or number plate light.
brake light fine .indicators fine.
could this be connected to the mod or maybe just a blown fuse.
not had time to check it out yet as was riding to work when I noticed it.
any help appreciated.
regards craig

Craig, not related. However look where you have been...

that's the problem
not done anything to the bike for the last 2000 miles apart from the starter mod on Friday then no lights today
craig

I followed kiwiroys step by step and it worked a treat.
the wire from the battery to the yellow solenoid wire , does it matter what thickness/gauge it is ?
its strange the brake lights work , just the tail light and number plate light that are out.
craig

From memory Craig, that is one of the fuses under the seat- one of them will be blown, possibly by a short somewhere. mine did this recently- caused by the horn application when I found one of the horn wires had shorted onto the oils cooler braided line and blowing said fuse. Brake light worked but not the tail light. Headlight might be gone too.

thanks oz my 1st port of call is the fuse box when I leave work.
I am hoping that's all it is.
love this bike , GRiSO would of been my 1st choice but funds would not allow.
but in the uk you don't see many guzzi so always gets attention.
craig

melonman wrote:

that's the problem
not done anything to the bike for the last 2000 miles apart from the starter mod on Friday then no lights today
craig

The tail light and the small bulb in the headlight are from a different contact of the ignition switch, they are that way so when you put the switch in Park position just those bulbs operate. A separate fuse usually.
If the fuse blows I would start looking around the tail for a pinched wire or short in the socket.

A trick when looking for an intermittent short is to replace the fuse with a high wattage bulb (I use an old headlight with a couple of short wires soldered on) wiggle all the wires and every time you create a short the bulb will flash, no fuses are harmed in the process.

tvboy wrote:

Thanks for the drawing. I see what you mean.
I was actually going to disconnect the battery from the starter motor and put my ammeter in the solenoid coil circuit to measure the current when 'starting' without engaging the starter motor. Then go from there.
I don't think the solenoid should draw more current with the starter engaging but it's worth checking both scenarios.
I need to learn how to attach drawings to these posts.

I'm still in shock over how much current is in those switches and little wires.

I'm still in shock over how much current is in those switches and little wires., I like that pun

You won't be able to measure this current with a regular multimeter, not normally anyway. the pulse of high current happens so quick it's too fast for the meter 15 - 20 milliseconds is all it takes for the solenoid to go clunk as it closes the main contact.
If you look at my sketch you will see that the coil on the right has positive from the relay on top but it also has positive on the bottom once the main contact is closed so the current drops to zero, all you would measure is the 10 Amps in the holding coil to the left.
Note the 2 coils are wound one over the other, it's common to draw them side by side for clarity.
There is actually a way, if you remove the main heavy cable from the solenoid then the heavy current will remain as long as you hold the button but the 15 Amp fuse will blow in around 1 second. It might also blow the fuse in your meter.

Thanks

You are correct about that. I realized after my post that my meter can't manage more than 20 amps.
No wonder this problem has caused so much grief.
Lots of variables.

The MPH fix is looking better and better. Plug and play.

I'll post a link here to my earlier thread on the subject,
I've been rabbiting on for years about the stupid Guzzi wiring causing misery for owners.

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The MPH solution is fast and easy. Only issue I had was that it came with a 15amp fuse and I would blow those every few months. Dr Pete Roper suggested that I go to a 20 and I've had no issues in the last 12 months.

Good info as well.

Thanks JohnA

BTW, what is the fairing on your bike? How much wind reduction would you say it provides?

Sorry, I just remembered I should have ask the fairing question in a DM.

Hi all
Just found a blown fuse under the seat
Replaced it took bike out all seems ok
Wonder if i shorted it doing the starter mod
Thanks for all the help
Hoping its sorted