Moto guzzi GRiSO 1100 non start

Over the winter
I have taken the battery off of my bike and trickle charged it.
I've recently put the battery back on the bike however it now won't start.
Basics have been checked like the fuses which are all ok.
We have tried with a jump pack also, but the starter doesnt even spin. You can hear the starter relay engage but nothing is happening.
We have power at the relay and to the starter. Should we have 2 feeds from the ignition switch when operated? Can you short the relay across 2 terminals to eliminate whether there is a fault with the ignition switch if so which points need to be shorted? The starter has been removed and tested on a work bench to ensure it spins and engages.
We have fitted a new relay just as a precaution however the same fault still occurs.
All earth points are good as is wiring and continuity.
Has anyone had a similar issue or does anyone have any other ideas as to what to try?

Sounds like the classic 'Startus Interuptus' issue. Run a direct, fused, feed from the battery positive to the delivery side of the relay, I believe it's the yellow wire.

Pete

Thanks Pete
I'll try your suggestion.
Had problems in the past but have always managed to get it going eventually.
This time it's doing my head in

Sorry Pete
One more question (sorry if it sounds stupid ) what size fuse?

From memory a 15 amp fuse is sufficient

Many Thanks

Hi CBH, A 15 amp is good and is what I have fitted.

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Disconnect the yellow wire from the starter relay and tape it up, then connect the fused wire direct from the battery to where the yellow was connected to the relay.

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Hope the pictures help.

Fantastic Guzzi Cat.
Many thanks

A good habbit is to always look at the voltage reading on the dashboard when you press the start button, and keep looking it untill the engine starts.

Supposing that when you press the start button, you hear the starter relay, and the voltage reading remains stable, above 12v, then its your starter solenoid does not close - the "startus interaptus"

Lately (over a year) that the same happens to me, I got away with it by cleaning the spade connector of the solenoid relay - the one thats on the starter, where the thin cable is attached, covered by a rubber cup.
Its the first thing to do - the cheapest and easiest.

Other than (and before) that - I have relocated the connections of the earth (ground) cables. I've connected the thick one, the one thats conected to the battery, to the right side of the engine and bolted it with one of the bolts that conects the engine to the gearbox. I bolted the other 2 thin ones, that are bundled with the oxygen sensor cable, on a bolt on the frame, a little above the left footrest plate. Those cables need to be connected real tight and when tried to tighten the thin aluminum screw that they were originaly fastened on, I've cut it.

The couse of the problem is that due to poor conections and thin cables (edit: and undersized relay), resistance is indused in the electric circut, so when current is drawn, the voltage drops enough for the solenoid not been able to close.

I think that for the 1100 at least, the solution is this:

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okuraner wrote:

Voila! It worked. As Pete wrote, I cleaned all terminals, sockets, earth strap but unfortunately it did not start. Then, through searchin internet, by chance I found "Allegato M-605" which is Moto Guzzi Technical Training February 2010. This 59 pages file is real life saver. On page 52, there is a section with head line "Problem solving course Sheet No:20 Starting Failure Applicability : All models.
I copied and paste the solution : "CAUSE: Insufficient cross section of the +12V wire energising the starter relay.
SOLUTION:
a) Identify the starter relay (orange/yellow, yellow, brown/pink and red/black cables)
b) Remove the relay and detach the Faston connector from orange/yellow cable, pushing
the tab down with a pin.
c) Prepare the additional length of cable (cross section 2.5mm2, as long as necessary)
d) Fit the Faston connector with the tab on the relay connector instead of the orange/yellow
cable.
e) Insulate the Faston connector from the previously disconnected orange/yellow cable.
f) Disconnect the Faston connector from the starter motor and fasten to the wiring harness
with a clamp to prevent it from dropping onto the silencer.
g) Connect the Faston on the additional cable in place of the old Faston connector.
h) Fasten the additional cable with the same clamp used to secure the starter cables"

It really worked. Now I wonder what are electrical engineers in Moto Guzzi doing all day long. Why don't they produce problem free motoryles.

So far, I've avoided runnig a new cable, changing the ground connections helped to reduse the resistance enough for the problem to appear only when the spade connector gets a bit loose/dirty/moist.

Many Thanks Petros and everyone else who responded. Hopefully next week when I get a chance to have another go at starting I'll have good news to report.

Thank you everybody. Up and running. Ran a direct, fused, feed from the battery positive to the delivery side of the relay. Delay replying due to heavy cold