starter not quite starting...

[The Disapproving Brit]

I recently replaced my starter - old one was just refusing to do anything despite taking it apart and cleaning it. The new one turns the engine over, but won't *quite* start it. If I drop it into first, it'll bump start literally as I push it off, so it seems it's just not quite getting there. The old starter started the bike fine until it died, and it kickstarts first time every time.

If I try and start it in first on the center stand, the back wheel jerks round a bit each time it turns over, but it never quite gets going.

Any ideas where to start?
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Current Bikes: 1983 Honda VF400FD / 2003 Honda VT750 Shadow
Bike Test Passed 18/03/09, Car Test Passed 14/05/13

[clancy]

tried holding the choke whilst you press the starter.
if it deosnt start after 5-10 seconds take the choke of and try normally.

that usually works for me when mine wont start.


if it sounds like its about to start i take it you tried giving it a little throttle?

leigh.
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KLX 300r

[The Disapproving Brit]

it's an auto choke

throttle doesn't help. It does start off the motor when it's hot though, so I think you're on the right lines.
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Current Bikes: 1983 Honda VF400FD / 2003 Honda VT750 Shadow
Bike Test Passed 18/03/09, Car Test Passed 14/05/13

[clancy]

it owrks when its hot? not on a cold start though?
my old bike did that, not much you can do i dont think.
try kick starting a few times, then the electric start.

if its cold, electric starts have a little trouble on their first go anyway.

leigh.
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KLX 300r

[Robby]

Quite probably a weak battery - the starter is taking all the juice, so you're not getting consistent strong sparks.

[dan3411]

i don't mean to hijack this thread but this question doesn't deserve a thread of it's own!

So even if the bike is kick start only and the battery is pretty bad would that hinder it's starting because the sparks aren;t strong enough?
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Suzuki Bandit 600N

[clancy]

[Robby]

I forget the exact terms, stinkwheel knows them, so a simple explanation.

When you use the kickstart, the battery only needs to supply enough current to get a coil going somewhere. This power is minimal, you can use a 9 volt battery, but you do need to have something.

So yes, you can kickstart something with a more or less flat battery. If it's strong enough to get the headlamp glowing it'll work.

Electric starts are a different matter. The single biggest cause of non starting among anything vaguely recent is a weak battery, I've noticed it particular on here over the last 3 years or so.

For an easy check, disconnect your battery and instead hook up a car battery or booster pack. See if it spins faster and fires up quicker.

[clancy]

just a quick thing, not to do with the question you posted.

my bike only has an electric start. but the bike will run with the battery out, if i just bump it into first it will start.

so does the battery only run the electrics? cuz the bike certainly doesnt need it to run.


leigh
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KLX 300r

[Robby]

Depends on the alternator or dynamo type. Some are self exciting, some require a power source. My old CRM 250 didn't, and couldn't, have a battery. Just kick start with everything running off the dynamo or alternator, whichever it had. Was fine, until you had to brake into a corner at night, and the lights went dim because the revs were too low.

[The Disapproving Brit]

After a bit of tweaking, I suspect my reg/rec is shagged. The battery gives out 12V with nothing on. As soon as I turn the key, the headlight and neutral light drop it to 9v. When I start it, it goes to 10.5V while idling up to 12.5v when I rev it. This sounds less than optimal.
____________________
Current Bikes: 1983 Honda VF400FD / 2003 Honda VT750 Shadow
Bike Test Passed 18/03/09, Car Test Passed 14/05/13

[Robby]

Doesn't sound like reg/rec trouble, sounds like the battery is totally shagged.

If you had reg/rec trouble you'd be getting about 40-60v across the terminals when you rev it.

Sounds to me like the battery is really weak - evidence.
No load - 12v across the terminals. Get an ammeter across them and expect a tiny reading.
Light load - 9v. Your battery has nothing to give.
Idling - light load and charging system. I'm assuming this a small bike of some kind, where the charging system isn't providing much power at tickover. It's providing some to run the lights and sparks, and the battery is absorbing charge but not doing anything useful with it.
Revving - charging system is putting out enough power, battery is gobbling a chunk of it.

Get a new battery.

[The Disapproving Brit]

Hmm...I bought a new battery about 3 months ago. The bike doesn't seem to charge properly, so (when it had a starter that worked) I had to swap them every 2-3 weeks or so. I'll try it with the other (newer) battery tomorrow (fresh off the charger), and see what that does.

If that gives the same readings, I'm guessing something is killing the batteries. Which, if not the reg/rec, I'm guessing is a short circuit somewhere. Of course, I'm a complete novice electric-wise, so may be completely wrong here too.

Bike's a Kymco Zing 125 by the way, so yeah...she's not big.
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Current Bikes: 1983 Honda VF400FD / 2003 Honda VT750 Shadow
Bike Test Passed 18/03/09, Car Test Passed 14/05/13

[mikey 2659]

if a jumpstart from a car battery fails check all your earth connections and the starter circuit for bad connections.when my brother changed the starter on his 650 katana he left off the gasket and this caused the crankcase to foul its action.

[mikey 2659]

if you have a meter,set it to dc amps then disconnect the positive lead going to the battery and connect it to the negaive/black lead of the meter,then connect the positive /red lead of the meter to the positive terminal of the battery,with everything turned off there should be no reading .the meter should be set to its highest range then reduced,you may need to use a different socket for the positive test lead.

[The Disapproving Brit]

Doesn't seem to be using anything noticable when nothings on. It blips 0.01A in time with the alarm LED when that's alarmed, and uses 0.25A with key in but not started.

At the moment, it's not desperate - I'm guessing the starter isn't essential for the MOT (next month), and the whole bike is gonna be stripped and cleaned as soon as I buy something bigger, so any problems will hopefully be ironed out then (or with my mechanical skills, more likely offset by bigger and more expensive problems of my own doing!)
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Current Bikes: 1983 Honda VF400FD / 2003 Honda VT750 Shadow
Bike Test Passed 18/03/09, Car Test Passed 14/05/13