Anyone noticed this starting quirk?

I have noticed a little starting bug. 2015 R3T around 4,500 miles, the battery is working on its 3rd year ( and you know I am anal about not letting a battery go beyond 2 years). Shame on me!

Anyway, I go to start the Rocket and it cranks normal then suddenly stop dead in its tracks. Release and hit the starter button again and away she goes. It acts just exactly like one of the cylinders comes up on the compression stroke and stops the whole process and the starter can't overcome the pressure. Kind of like an air conditioner trying to overcome head pressure on startup. I don't recall having this before, but it has happened several times. I might expect this on a high compression engine, but not with the rocket compression ratio. Sometimes it doesn't happen but I have experienced it about a half dozen times recently.

Now I an old school and many of my first bikes were kick start with manual advance and manual compression release. If you ever forgot either you know what my point of reference is. Just seems strange.

one reason might be that while it is cranking if it falls below a certain voltage the relay disengages and it quits cranking. on the second try it starts. u can check with volt meter while cranking.
best guess need new bat.

Put a jump battery on and if it does not fail as you described - change battery time.......

Okay...Going back to my golden rule. Two years and it's gone. I ordered a new battery, my old favorite.... Yuasa YTX20HL-BS. 18 AH 310 CCA. I always get the BS designation where I get to acidize the battery myself. That way I know it is fresh off the shelf.

My thought is...I bought the bike in 2015 and who knows how long it had been sitting around before I got it. I keep my batteries on an Optimate year round. If the issue continues, I'll look further.

My 2012 Roadster still has the original Yuasa in it. The battery is pulled for the winter, stored indoors and hooked up to a battery tender the whole time. Summer time comes, the tender is only installed when the bike is going to be sitting for over a week. Still starts strong.

I've seen Gold Wing owners run their Yuasas this way for over 8 years before replacing. I always carry an Antigravity back up battery just in case. When replacement time comes, it'll be a Yuasa YTX20HL-BS, same as Bedifferent.

Bedifferent said:

I always get the BS designation where I get to acidize the battery myself.

Click to expand...

And maybe even can refill if it starts to dry out. The drying thing is a BIG issue here in central Spain.

Just replaced the original battery on my 2011 R3T a few weeks ago. Kept on a tender through the winter but left in bike in an unheated garage.

Battery worked perfectly ........... until it didn't

Just bought the 310 Yuasa for Bess plus a battery tender.
There’s 0.9l of acid in there!