Bad battery, or bad voltage regulator? - Ducati.ms

number9 · Mar 20th, 2006, 8:10 pm

I bought my 900SS on the weekend, and have had trouble starting it since I got it. I should add that I'm in Southern Maine, where it's still cold

and the bike is stored in an unheated garage.

When I try to start the bike the headlight comes on & the engine cranks, but it sounds like it's not cranking, well, "hard enough". On Sunday morning I put the battery on a 10A battery charger I had lying around, and then about half an hour later (when the charger said it was charged) the bike started first crank with the battery plugged back in. Trouble is, I went to start it again tonight and had the same problems -- light comes on, I can hear the fuel pump prime, but the bike won't start.

I've charged the battery (again) but it's too cold and dark to go outside and try and start it

My question is, is this a bad battery? The bike only has 4500mi but was stored in the cold & I can't vouch for the battery being the original one with the bike or not. The water levels on the battery look fine, and I can't see any major corrosion of the plates. I still think that the battery is the problem, though... what do y'all think?

Shibbydevil · Mar 20th, 2006, 9:59 pm

take your volt meter and charge the battery... start it up and then watch the voltage... if it is dropping while its sitting there the regulator is bad. If the regulator is good the voltage will pick up when you rev it and will stay at a decent level.

Ryan

bruce19 · Mar 21st, 2006, 6:12 am

Chris:

I think checking the battery and regulator would be in order. I will check with Ben today and see if he did check either. Just one bit of advice: get those carbs re-jetted to what they call Stage 2. Stock SS carbs are way lean and it will take your bike a week to warm up in ME. Well, maybe not a week, but my bike had to run about 10 mi. before it would begin to warm up.

bruce19

**edwyun** · Mar 21st, 2006, 8:50 am

On a wet battery, fully charged, the battery voltage should be 12.6v.

With the bike running, the battery voltage should increase from idle around 1200 RPM to around 3000-4000 RPM to 13.8 to 14.2v. After about 4000 RPM, the voltage should max out at 13.8-14.2v, no more.

After riding the bike a good while and turning everything off, the voltage should should be above 12.6v and SLOWLY (i.e. couple of hours) come back down to 12.6v and stay there for several weeks before losing some charge. FWIW, my wet battery stays at 12.4-12.5v for a month after a ride.

If things are not what they should be, you may have some corroded wiring somewhere, you may have some bad connections somewhere, you may have a bad battery (even though it was apparently fully charged), or you may have a problem with the R/R.

ducatimike · Mar 21st, 2006, 9:43 am

Seems like the motorcycle batteries are not as robust as car batteries. It helps to keep them charged using trickle chargers when not in use. I probably have 4 or 5 used, dead batteries in my garage from my 3 ducatis that I own. I find that after a while (can be as long as 3 years or less) the battery will not hold its charge well, and has a difficult time turning the motor over. I see this especially in my Monster with high comp pistons. If the battery is not in tip top condition, the bike turns over slowly and will not start. When I open the throttle just a bit, which is necessary to get the bike to catch, the compression increases slightly, and it really bogs down the battery. Cold temperatures exacerbate the problem. The advice previously offered is all good. Check your chargiing circuit. If its charging then the your problem is easily fixed with a new battery.

Mike

number9 · Mar 21st, 2006, 7:21 pm

shibbydevil: No problem, I'll give it a shot! Thanks.

bruce19: You know, I think this problem might have come down to rider error more than anything.

I think it could be two things, firstly I might have left the ignition in Park instead of Lock (my 748 didn't have Park? I just always turned the key as far south as it could go). Also, I don't think I was choking the bike correctly -- I was trying to crank it with the choke off, then apply the choke as it was cranking; whereas I think it's better if I turn the choke full on and THEN try starting it.

I guess I'll know tomorrow afternoon when I try to start the bike after it's been sitting for 24 hours. I asked my local dealer about the jet kit, I will probably wait until I put the Scorpion cans on before I do that. But I have to clean them up first, they're kinda scrappy.

edwyun: Thanks for the numbers. My multimeter is a piece of crap, so I need to find a better one before investigating. As I said to Bruce, I guess we'll see what happens when I try to start her tomorrow; I rode about 30mi tonight and it was fine. Also, I cleaned up the terminals on the battery pretty good, as well as the leads that connect it to the bike's electrical system.

ducatimike: Yeah, I'd agree -- they don't store nearly as well as car batteries, and they seem to die more easily as a result of cycling them too "deep". I think they are disproportionately "weaker" than car batteries are, even with the size difference. And you're right, cracking the throttle seems to make it harder to start, not easier. It has been a long while since I've had a bike with carbs!

bruce19 · Mar 21st, 2006, 7:45 pm

Chris:

My experience with the stock carb jetting on that bike is that you have to put it on full "choke" and once it fires up leave it for a bit before you try to "blip" the throttle. It will take a while to warm so be patient. Once you've done the jet kit, things will be a lot easier. BTW, I did go over to Ben's shop to ask if he had checked out the battery. He wasn't around today so I don't have an answer yet.

bruce19

number9 · Mar 21st, 2006, 8:06 pm

Quote:

Originally Posted by bruce19

Chris:

My experience with the stock carb jetting on that bike is that you have to put it on full "choke" and once it fires up leave it for a bit before you try to "blip" the throttle. It will take a while to warm so be patient. Once you've done the jet kit, things will be a lot easier. BTW, I did go over to Ben's shop to ask if he had checked out the battery. He wasn't around today so I don't have an answer yet.

bruce19

Yeah, I did notice that -- the bike would stall if you blipped the throttle too soon after starting it. I will get around to the jet kit, I'd just prefer to do it all together. I've got some great cleaner for the cans too, I hope to get around to `em this weekend. Let me know what Ben says!

Dutch900 · Mar 22nd, 2006, 5:42 am

I had the same problem on my '95 900 CR. Winter blues... I had charged and topped off the battery all winter. I tried starting it and it turned over very strong, but just didn't have the spark needed. So I cleaned the plugs, to no avail, then I replaced the plugs and she started RIGHT up. Good luck!

bruce19 · Mar 22nd, 2006, 11:52 am

Chris:
I got called to do a case this AM so I haven't been able to get back to Ben. I will call him shortly though. I did have a short talk with Justin and he mentioned the new plugs he put in the bike. The code he gave me didn't seem right, and I know he got them from a generic bike shop. I'm wondering if he was given the wrong plugs and they are now in the bike. Please check that out. And, it wouldn't hurt to check the battery on your own anyway. I'll get back to you on the Ben thing.

Bruce19