Hey guys I have a question.
Sometime the bike is really hard to start and it will just keep trying till the battery goes flat.
Riding the bike today when I got home the battery is at 12.58 volts. If I put it on the battery charger it will go to about 13.5 volts.
Anyway what could be causing to be hard to start, now this doesn't happen very often so it's hard to diagnose, 99% of the time it starts fine

Thanks

12.6 is fine for a lead acid battery so you don't have any battery problems. You could measure the output voltage at the terminal and rev it to 5000 briefly to see if it gets to 14V. After you charge your battery if you measure the voltage you have to remove the static charge which will be handing around the terminals which is why you get a high reading.

Looks like the problem is elsewhere. Check both sides of the boots on the carburettor and make sure there are no other vacuum leaks. I'm sure there'll be other suggestions soon...

I checked the battery this morning and it's at 12.13 should it lose that much power over night?

you can't judge a battery purely on it's voltage...you need to "load test" it.

Take it to you local auto store (Advance or similar)..they have a load testing machine which will tell you the health of the battery...cold cranking amps etc...and whether it just needs a charge or whether it is shot.

Cookie

Quote from: Jimbob on November 24, 2017, 05:27:38 PM
I checked the battery this morning and it's at 12.13 should it lose that much power over night?

They have checked it and said it's good

Any idea on what could be causing the issue where it won't start

If the battery voltage drops overnight, the battery might be circling the drain. MC battery's are not as robust as automotive battery's by virtue of their size, when a MC battery is on it's way out it can die giving you little or no warning. Or you might have some sort of parasitic draw...something drawing power even though the key is off.

https://www.batterystuff.com/kb/articles/charging-articles/testing-your-battery-for-parasitic-load.html 

"Any idea on what could be causing the issue where it won't start"

Old gas? Today's fuel is pure compost as far as shelf life goes.

The gas I put in there is always fresh I ride the bike everyday so go through a tank of fuel every 1-2 weeks

Check your choke to see if it is both within adjustment and operating properly.

As suggested from another board member you might want to switch the petcock to PRI for a few seconds before attempting the start.

What does "hard to start" mean exactly?
Cranking slowly? Cranks fine but never fires? Fires up but won't idle?

I have had a GS500 battery that tested as "ok" by a auto parts store but replacing it still fixed all my starting problems. Unless you ride every day or have a lithium iron battery I wouldn't expect a motorcycle battery to last more than a couple years. Buying a new one is a relatively cheap way to see if that is your problem. Worst case scenario you know you have a good battery and can move on to what else the problem is.

BTW, diagnosing a starting problem is a good way to quickly kill a battery. I don't know about you but when I'm trying to find out whats wrong with my GS I end up running the battery down and then jump starting it or putting on a battery charger. Sometimes I do this multiple times while fixing the bike. Traditional motorcycle batteries will quickly go bad under that sort of punishment so if you do buy a new battery and find that wasn't the problem you may want to go back to your old battery and run that one into the ground while you troubleshoot your real problem.

So it will turn over fine but not fire.
I do ride it every day I work (5 days a week)
Normally it won't fire after a day off so I have started putting it on a charger when I have a day off

Quote from: Jimbob on December 02, 2017, 09:12:12 PM
So it will turn over fine but not fire.
I do ride it every day I work (5 days a week)
Normally it won't fire after a day off so I have started putting it on a charger when I have a day off

How long is your commute? Are you possibly draining the battery more than you charge it because the commute is too short? Especially at this time of year, when regular cold starts really test your battery. You may want to fit a longer ride in once a week to get the battery charged and burn off any condensation in the oil.

Also, how are you starting it? It's more effective and easier on your battery to use short 5 second max. bursts (interspersed with 5-15 second breaks) than to just hold your starter button down. Occasionally in this cold, my bike doesn't start first time (although not since I installed the AGM battery). I just try again and it starts on the second go.

My ride is about 25 mins each way, I only try starting for a few seconds then I'll stop wait a couple of seconds then try again. What's the best way to test if something is draining the battery? Also when I ride my cruising rpm's is about 3.5k is this not high enough to be charging the battery?

25 min @ 3.5k rpm is plenty to charge the battery back up.

Quote from: Watcher on December 15, 2017, 08:12:18 PM
25 min @ 3.5k rpm is plenty to charge the battery back up.

This is true as long as everything is in perfect working order. A little bit of corrosion on the connectors anywhere between the stator and the battery can knock the charging voltage down enough to make it not charge. So, do the checks. My own experience was that mine was perfect and then 6 months and 1500 miles later it needed cleaning to stay functional. I think the GS charging system requires a little bit of regular maintenance at about oil change cadence.