Electric start problems (mostly when cold)

[alexlawriewood]

Hi all, hope you're well.

So I've been having some problems recently with the ol' GS. Replaced all the gaskets a few months back when the head gasket fell to bits (got me nearly all the way home from abroad, at least!), and did the valve clearances. Everything was going swimmingly at this point, had never started so well, it was magic.

Anyway, more recently it's been trickier, and often completely impossible, to electric start from cold. I'm having to push it up the driveway of my block of flats and bump-start it five times before it gets going. Once it's warm, it mostly starts fine (although not quite always). Before I go full-out crazy and retrofit a kickstarter, any suggestions?

The weird thing is, the starter motor sounds like it's turning perfectly happily, but it just refuses to fire. Pulls a little if I start it in gear, so I figure it's not the starter clutch.

So, summary:

- recent engine rebuild, spark plug change, valve clearances
- electric start was great for a bit afterwards, now rubbish
- pushing a 275kg bike up a steep hill is hard work
- still love the thing

Cheers!
A

[tom203]

Next time you go to cold start it , first remove signal generator cover so you can watch the little gizmo spin when you press starter button- I imagine 100 revs/minute should be enough. If this appears OK, then you can rule out starter clutch.
Make sure your "choke" cable is fully activating at carbs (my plungers pull out about 10 mm)
You can push this thing up an incline ? new workout routine!

[alexlawriewood]

I'll have a poke under the cover there, but it sounds the same as normal, and like I say, it pulls the same as normal if I tap the starter when in first.

The choke, that's a thought... I did have it off and didn't put it on again right (I now have to hold it to keep it on, it doesn't stay)... seems to be held in its set place by just the tightness of the screw on the control? Or am I missing something?

And yeah, it's pretty hard work. I've been going out in a t-shirt in 10? British winter and finishing up hot and sweaty ten minutes later!

[hampshirehog]

Make sure you have the choke linkage set up properly. You can get it the 'wrong way round' if you assemble the carbs without paying attention.

[trippivot]

check voltage at the battery while electric starting your bike.

I have seen a voltage drop below the ignition system threshold while the starter motor is energized -- battery is just enough to turn the starter and not flash the ignition.


you can attempt to assist start it with a second 12V battery attached (while cold) to prove or dis-prove the theory.

[alexlawriewood]

I'll have to have a good poke around at the choke. It does still work, but I guess that'd happen if it was a bit wrong anyway.

Battery thing is an interesting thought, and I suspect the battery might be a bit iffy. Ex-housemate did accidentally empty it all out on its side once...

[alexlawriewood]

Okay, spent a pleasant half hour out in the wind and rain just now and did a few measurements on the battery. Main thing I noticed that seems possibly suspect is that the battery volage drops to about 9.5V when running the starter, down from about 12V (yeah, not been using it over Christmas!). That seems very low?

I'd chuck in a known-good test battery, but don't have any to hand right now. I guess next thing to do is test for spark when running the starter, when it's drier and light.

[posplayr]

Okay, spent a pleasant half hour out in the wind and rain just now and did a few measurements on the battery. Main thing I noticed that seems possibly suspect is that the battery volage drops to about 9.5V when running the starter, down from about 12V (yeah, not been using it over Christmas!). That seems very low?

I'd chuck in a known-good test battery, but don't have any to hand right now. I guess next thing to do is test for spark when running the starter, when it's drier and light.

There is a "Quick Test" that will provide a wealth of diagnostic info but you will need to charge that battery first. After the quick test measure the voltage to the coils anything under 10.5v can be quite problematic when cold starting.

[Guest]

Definitely try a battery first, or jump start it from a car to prove a point. UK winters are particularly harsh on bike batteries. I always used an Optimate on my bikes once they were a few years old. I still had the original battery on my seven year old Hayabusa when i sold it, but during winter it needed a little help from the Otiimate every so often (summers were fine without).
Even here in Oz, my K6 Gixer can be a little reluctant some mornings unless I give it a boost. Then it's a different animal altogether.

[tkent02]

If you jump it from a car make sure the car isn't running.

[Steve]

I will join the group that suggests a battery change, but will go a bit farther.

I know you said you checked the valve clearances, but if you have no idea how long it had been before that that they were checked, you may have had some crud that was stuck in the valve seats. Now that the engine has been running, the crud has been worn away, letting the valves get all the way down to the seats, instead of resting on the crud. That wil tighten up the clearances to the point that the bike will be harder to start.

Connect jumper cables to a NON-RUNNING CAR first, to verify whether you have a battery problem. If that proves to be your problem, you can wait until your normal 4,000 mile interval for valve clearance checks.

.

[trippivot]

If you jump it from a car make sure the car isn't running.

More average riders that get stuck need to know this detail .. and be careful with the HUGE clamps - pain it is not a 1 size world.

Motorcycle size batteries seem to be getting more and more delicate and the MFGS' (seems like all) really are forcing customers into using the warranty.. Buy the best you can afford and keep hold of the receipt.

dumping and refilling -ugh- I know it has been done successfully , BUT you have to expect trouble from an abused battery.

[spyug]

I think you are on track with the electrical issue and doing the tests as suggested should confirm this. If the battery runs down quickly and especially as it gets close to 12 volts or under it will still spin the starter but their won't be power enough to create good spark.

I would also suggest you check battery voltage (resting) against the voltage at the coil as this can be another source of problems. If the battery shows a 12+ volt and the coil connection is 11v or less you will have a problem. Clean up all the connectors between the battery and the coils as resistance caused by corrosion is causing this voltage drop. In a perfect world the voltages should be the same (they won't be but should be close .5 v or less).

If cleaning things up doesn't help then you should consider the Coil Relay Mod which will allow full battery voltage to get to the coil, resulting in better spark and easier starting.

And as Steve mentioned, if the valves are out of adjustment that too can make for very hard starting so think about checking and or re-doing those too.

Good luck with it.

[alexlawriewood]

Put in a new Motobatt beast thing, started! Cheers, all. Fingers crossed I don't have to do the valves again yet, will see how it pans out.

Now just got to run through the stator paper checks, 12.7V across the terminals at idle with the lights on doesn't seem terrific...

[argonsagas]

Put in a new Motobatt beast thing, started! Cheers, all. Fingers crossed I don't have to do the valves again yet, will see how it pans out.

Now just got to run through the stator paper checks, 12.7V across the terminals at idle with the lights on doesn't seem terrific...

12.7 at idle is OK....voltage normally increases when RPMs increase.