Won't fire unless starter button released

[Scottrtho]

My Valk sat almost a year with no battery tender. The ol' girl cranked about 30 seconds before battery petered out ... didn't pop once but probably got fuel into the bowls.  Charged at two-amp rate overnight and it started up the next day, easily, but only when I let off the starter button.

I have read about others on here that have bikes that behave this way. Mine never did...always started happily and quickly with button depressed (while cranking).

So I rode the bike for an hour and now it starts like it always did...I don't have to let off the starter to assure the plugs get juice to spark.

My conclusion is that the battery must have enough voltage/ampacity available 'while under cranking load' for it to start straight off without releasing the starter button. anything less and it will still crank heartily, but fire only once you stop cranking...very awkward actually.

Regards,
Scott

[Bighead]

Your assumption is correct.

[Pete]

Your assumption is correct.

++22

[Jess from VA]

That is often the classic symptom of a failing battery.  (except you let it sit a long time, so maybe not)

If, a week later (on no charger), you again get a good crank but no start (until you release the starter button), it is time for a new battery.

You can keep the battery on a (smart) charger and it will probably fire up and go all day, several times, until it doesn't.  

So order a new Yuasa now with the acid on the side.  And it will be ready when you need it.    

[MarkT]

+1 on all of the above.  If you don't replace it, next will be a push start when you're out. Yep done that a number of times over the last 21 years.  I actually added a switch so I can shut off the headlight and spots so they don't drain the battery at all before starting, when it's marginal.

[Willow]

Your assumption is correct.  The overnight charge was not enough to bring it to full capacity.  The alternator did.

The question now is whether the battery will hold the charge.  When you let it sit overnight, or a few days, and start it again you'll know whether it needs to be replaced.

[thewoodman]

It is also an symptom of a loose ground strap and there is one underneath the alternator that I missed for a long time and caused me to burn at least 3 starter relays

[Scottrtho]

Good to know about the ground strap...I will double check it. What do you guys think of "Big Crank" brand AGM batteries?