Not my Ducati but my winter hack BMW r1100rt. It's been slow to start for months. My question is, if the battery is turning over the starter motor ok, does that mean the battery can't be at fault?
no, my CBR would turn over, make all the right noises but wouldn't fire apparently the power has to be bang on for ECU to make it fire, a new battery fixed it at least for a Honda anyway
Have you put a multimeter over the battery prior to starting and when it’s cranking? It could be the starter motor is on it’s way out. I’m not sure the BMW r1100 has an ECU, however having checked they do. My R1150 would not start when warm which was odd, let it cool down for 10-20 minutes and everything would be fine. I ended up replacing the battery and problem solved.
I'll try a battery charge and then a new battery if that helps. I figured if it turned over the starter ok it would be fine
Jump cables from your car battery to the bikes, if it spins over quicker then it’s the battery, if not then it’s probably the starter motor.
I don’t know how easy it is to get a multimeter on the battery to test it but if you can then it should read >12.5v and not drop below 11v (10.5 at a push) when you crank it, rising immediately to about 14v once it starts and the charging circuit kicks in. When starting the starter motor pulls everything the battery has, if the battery isn’t in tip-too condition then there’s not enough power to energise the coils efficiently, leading to a weak spark. Chances are you just need a new battery but it may also be worthwhile cleaning the earth/ground points too.
It’s fairly easy on a R1150rt as it sits underneath the riders seat, certainly easier than my MV. Which reminds me I have to find where it lives………
My Monster has always turned over slowly but recently got worse, and due to it having no chokes in the carbs it can easily flood if it doesn't catch first time. I replaced the battery this year and it's immediately much easier to start, despite the old battery appearing to be fine under any test. In fact I put the old battery (Motobatt) onto my Son's old car and it was fine but I guess a 1.4L, 4cyl is easier to turn over than a 950cc high-comp twin? My old Guzzi is heavy on batteries, despite having a huge battery, it's on it's 3rd in the 8 years I've owned it but it's got a starter motor/setup like a car (on the flywheel) and even more compression than the Monster.
I'd be real careful doing this, I've lost CDI boxes doing exactly this... (Ps: though I have still done it with motorbike batteries...maybe it is too high an Amp output from a car battery??)
I agree with WC Paul ..... it's amazing how much a bit of gunge build-up can affect the current available in DC circuits . Another suggestion would be to get some replacement battery cables from this firm .... they are made to a very high spec and have often worked miracles for people with persistent starting problems . Most manufacturers tend to skimp on quality when it comes to details that the buyer can't actually see ...... and battery cables is one of those areas . https://www.exact-start.com/
The most likely effect from doing this is sparking/arcing when removing/attaching the cables if done 'lazily' or carelessly. You can't have too high current available - the circuit will take the current it needs and no more.
Indeed, a 12v battery is a 12v battery so, no matter how big (AH) it is, it will be fine. Car engine running might cause problems though.
