Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > No Go

[900SL Pete]

Bought the 748 some 3 weeks ago, been out a couple of times but not run it for 2 weeks.
I've come to start it today and no go. Its as if the battery is flat. So Ive charged it up for a couple of hours, the engine doesn't even turn over. There's just a whiring noise on the left side, and the fuel pump is running ok.

Do I need a new battery or is it something else


Anyone who can shed some light.

right hand side of the bike near the starter solenoid is a white conector, its a pile of pooh, go ensure its clean and well connected, .. that may sort it .. its a known issue .. you'll find it jut in front / above the battery somewhere ...

Good luck

[PDL]

Originally posted by 900SL Pete
Bought the 748 some 3 weeks ago, been out a couple of times but not run it for 2 weeks.
I've come to start it today and no go. Its as if the battery is flat. So Ive charged it up for a couple of hours, the engine doesn't even turn over. There's just a whiring noise on the left side, and the fuel pump is running ok.

Do I need a new battery or is it something else


Anyone who can shed some light.

Does the bike have an alarm?

[keefer]

sprag clutch

[900SL Pete]

Forgive me for being stupid, but what is a sprag clutch

I've managed to dtart the bike with jump leads so I spose this confirms its the battery!

So I'll nave to spend some money in the next few days.

Thanks for the advice Guy's

[Lee1980]

Originally posted by 900SL Pete
Forgive me for being stupid, but what is a sprag clutch

I believe it is the bit of the starter that comes out to engage on crank to start it then springs back once bike starts if it goes it doesnt engage i think

[keefer]

if you have started it with jump leads it unlikely its the sprag.
but your description was of a noise coming from down the left side. (starter motor) but the engine not turning over.
if the starter motor is turning then so must the motor unless the sprag clutch is not griping.
so any way you running good luck

[JPM]

Could be the solenoid I think, big circular think behind the heatsink etc, I ended up having to put a cable tie round mine as it kept vibrating lose every now and again

[nelly]

Did you jump it via the battery connections or directly to the starter motor? If you connected to the battery then it's doubtful the solenoid or the connector Dibble speaks of is the problem.
The sprag clutch is a "one way" bearing. When the starter spins up it turns a gear on the back of the flywheel that has the sprag mounted in it. The sprag grips the flywheel and turns the motor over. Once the starter is disengaged and the engine is running the sprag just sits there.
Your sprag clutch could be on the way out. The extra boost from the jumper battery could be enough to spin the starter motor faster and cause the sprag to grip harder and hence start the engine. It works like a centrifugal clutch............
It's not easy to check as the LHS engine cover needs to come off. Try a new battery. It may be enough to spin the starter fast enough to engage, but it may well give up in the future.
I don't have a reason for it, but especially on hi compression motors, the sprag sometimes plays up on cold engines. Once warmed through and for a few days after they work fine. Leave them for a while and they misbehave. Proabably down to thickened oil??

[keefer]

you can hear them chime as they grip briefly then let go.

nicely put though Nelly