what is that?

[foliver]

Hello all, i've just finished the overhaul of my 75C 1986, that was sleeping the lasts 6 years.

The first day i started the bike the relation starter relay- Baterie was bad ( both new units).
After charging the batterie, all went ok, until yesterday, that happens the same that today.

Today when I got home from work, after a 20 minute ride, I turned off the motorcycle to open the gate, when I turned it on again (it turned on instantly), I heard a strange sound, I thought it was the fan but it was different, it turned out to be the stuck relay, the bike wouldn't turn off.
I had to put the 1st gear, brake and release the clutch, there the starter motor was released. ( the batterie is at 12,7V)
Why can this happen to me? If it turns on ok and first when leaving work and at home when I arrive, no….

Can be just the battery and the relay??

thanks!

[The Mighty Gryphon]

Is your starter relay new? 

Have you opened the relay case to clean the contacts?  If you did, you may have disturbed the insides so the spring doesn't open the contacts reliably. 

[foliver]

Hi Mighty, is new

[frankenduck]

Even if it reads 12.7V that doesn't matter because what really matters is how many cranking amps it can put out.  Take the battery to an auto parts store and ask them to load test it for you.  At least in the US any auto parts store will do that for free.

[foliver]

welll , that's a good point.
The biggest batery i was able to find was 18ah.
So maybe that's is the point.
I guess i'm going to but a battery tender, and plug the bike all days....until i find a powrfull battery......

So talking about the starter relay: it welded 4 or 5 times, now it's working ok.
It's new, i haven't opened it yet
should I open it now to polish it?

[Past-my-Prime]

I won't tell you how to do yours but there were little tabs on either side of mine that allowed me to open it and sand the contact points of the high current (will be obvious). After that, never welded again. But I buy a new AGM battery every few years, possibly over-spending!

[frankenduck]

welll , that's a good point.
The biggest batery i was able to find was 18ah.
So maybe that's is the point.
I guess i'm going to but a battery tender, and plug the bike all days....until i find a powrfull battery......

So talking about the starter relay: it welded 4 or 5 times, now it's working ok.
It's new, i haven't opened it yet
should I open it now to polish it?

It's not Ah or measured volts that matter. It's cold cranking amps that matter - which is what load testing addresses.  CCA measures how many amps a battery can put out for 30 seconds, not how many amps it can put out for an hour.

[foliver]

I won't tell you how to do yours but there were little tabs on either side of mine that allowed me to open it and sand the contact points of the high current (will be obvious). After that, never welded again. But I buy a new AGM battery every few years, possibly over-spending!

Hello Past, i’ll do for sure! Txs

[foliver]

It's not Ah or measured volts that matter. It's cold cranking amps that matter - which is what load testing addresses.  CCA measures how many amps a battery can put out for 30 seconds, not how many amps it can put out for an hour.

Txs Frankenduck, i didn’t knew this measurements exists. I’ll call some shops.