Replaced battery and now bike won't start.

[Groovylonghorn]

So I went out and tried to get the bike to start. After about the 5th attempt there just wasn't enough juice to get it going. I waited 5 minutes and tried again but all I hear is like a small spinning motor sound, kind of what a small roto tool sounds like. The battery was already on its last legs so I went out to cycle gear and got a new one. They filled it with acid there and I dropped it in and all I get is that same roto tool sound. Do I need to charge the battery or is there something else wrong? Thanks y'all!

[BockinBboy]

Yep you need to charge the new battery.   

- Bboy

[adidasguy]

Spinning motor is not it. If battery is weak, the motor can not spin because it is connected to the engine with a one way friction clutch.

This is your problem...

[kvon11]

Yep you need to charge the new battery.   

off topic, but ive always been told that...but ive never actually had to charge one.  i always say "well lets just try it" and she fires right up and runs fine... haha   maybe i have the magic touch 

[adidasguy]

Yep you need to charge the new battery.   

off topic, but ive always been told that...but ive never actually had to charge one.  i always say "well lets just try it" and she fires right up and runs fine... haha   maybe i have the magic touch 

Also depends onthe battery. If you add acid - you must charge it.
LiFe batteries are charged up right out of the box. Probably many gel sealed batteries, too.

Remember: weak battery will not make the starter motor spin. We do not have a starter "solenoid" that makes the starter catch with the motor. All we have is a relay that turns on the starter motor. The starter motor is connected to the crank with a one way mechanical slip clutch. One way it always catches (starting) then slips when the engine crank is turning faster than the starter motor. See video for explanation.

[BockinBboy]

Remember: weak battery will not make the starter motor spin. We do not have a starter "solenoid" that makes the starter catch with the motor. All we have is a relay that turns on the starter motor. The starter motor is connected to the crank with a one way mechanical slip clutch. One way it always catches (starting) then slips when the engine crank is turning faster than the starter motor. See video for explanation.

Gotcha

Btw, I took the original post to be more like when the motor does turn, you hear the higher pitch sound from the starter, but the engine doesn't fire up - but rereading his description, it seems to be more like the sound posted in your video, and the engine not turning at all... which I hadn't heard before, and definitely sounds different than what I was thinking.

- Bboy

[kvon11]

Also depends onthe battery. If you add acid - you must charge it.

Yep... batteries where i need to pour the acid in...  a few times now, i am surprised that it works too... must have been about 2 or 3 batteries.  i pour the acid in, let it sit for a while.  drop it in the bike.   go to get the trickle charger but stop and figure "maybe ill see if it works.... " and then magic happens and it fires up. 

oh well.  ill let this thread get back on topic and stop spreading information that probably confuses most.

[Groovylonghorn]

Oh man, that's exactly what it sounds like. Dang, SxSW is happening and parking is ridiculous right now.  I was hoping it was a quick fix but it looks like I'll have to work on it this weekend. Thanks adidasguy for the great info!