URGENT!! Spark dissapeared

[The Artist]

Hello

QUite urgent
Derbi senda from 2000.

Worked yesterday didnt today. I tried to start it, it wouldnt, puffed a bit of smoke but nothing major.

The flywheel is slightly chipped but didnt affect it yesterday. A new one came in the post today, I fitted and it did the same, puff of smoke but not running. halp! Don't know what ive done.

It may have got dripped on last night but I checked all connections and they seemed ok. I need this bike working asap so please help.

What should the readings be out of the maneto? e.g. red green wires

[Finglonga]

Have you got a spark at the sparkplug or not?
____________________
Andy Sez....
F.Y.Y.F.F.

[Polo]

It always turns up in the place you least expect it.

Where did you have it last, start there and trace your steps backwards. It can't have gone far.
____________________
My mum smells your fingers

[The Artist]

No spark at all. I changed plugs but still nothing. What could possible have gone wrong!

[iooi]

So it worked with the old flywheel, but it was chipped.

New one arrives, you swop it over and it don't work.....

Seems the plug is not the only thing not sparking

Guess its either wrong one or you have fitted it wrong, which should be pretty hard as it should be keyed.
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Just because my bike was A DIVVY, does not mean i am......

[Finglonga]

As said above the flywheel will only go on one way, check everything you did while you replaced it. Chances are there is something you may have forgot to re-connect on reassembly.
____________________
Andy Sez....
F.Y.Y.F.F.

[Richard_Schmid]

I think he tried firing it up before fitting fly wheel, nothing. Changed Fly wheel. Nothing.

Check all your connections are dry, if you think they have been dripped on.

Richard

[The Artist]

Thanks for the smart comments.

Yes I tried it this morning with no change from yesterday apart from being in a cold shed, seat had water on it.

I decided might aswell change flywheel as this one wasn't working still nothing. I have figured its not the flywheel but something else. All connections look ok, but I will take each one and leave blow heater on the whole leccy system for a bit tommorow.

What should the readings from the coils on the stator plate be?

[The Artist]

by smart comments i meant "iooi"

[iooi]

[The Artist]

Hi,

My 1st post did say that it didnt work with the old flywheel. "i tried today, then changed the flywheel."

Wont work with either flywheels. Battery ok, fuse ok, all connections dry, Mechanic friend who doesnt do bikes still said I need a new stator plate with coils.

[Cigaro]

Hold-up.

Do you know for sure it's a spark problem?

I don't see how it could have been puffing smoke without a spark.

[The Artist]

Im sure because i took plug out and it wont spark. And yes, I was holding it against bare metal, i tried different places aswell. I fiddled with cables and used multimeter on HT lead to frame, and nothing at all came through.

[The Artist]

smoke could have been hanging in the exhast perhaps, or perhaps it was sparking at first, just I knocked something when changing flywheels

[Odie]

[Cigaro]

Is it leccy start? Have you tried bumping it? I had a scooter once which had enough power in the battery to turn the engine over after being left standing for a month, but wouldn't fire the spark plug.

[iooi]

I would remove the flywheel again and see if you have caught anything when removing/replacing it.
Also check the timing.
Best place to check spark is against cylinder, might try a new plug as well just in case.
Hope the multimeter has a good range on it, as metering the HT would require a DC in the order of thousands of volts.
Takes about 600V for it to spark outside the engine, but approx 10 to 50 times when under pressure in the cylinder.

If you have ever nicked a shock from a plug you will know just how potent it can be.... And not something you will ever do again..

I would also be looking at the HT lead at both ends to see if its in good condition.
____________________
Just because my bike was A DIVVY, does not mean i am......

[cheekythomas]

Its a Derbi senda with no spark... its gonna be stator or cdi, both are more common than burberry hats on chavs

Theres 2 different ignition systems used as they dont mix so make sure you get the right one...

Leonelli 5 wire system (Rotor and CDI will be clearly marked Leonelli)

Ducati 3 wire system (again will be marked Ducati -although new ones might be marked LB since they started being made in china)

Stator Checks are...

GREEN to EARTH = 820 ohms + 10% (CDI charging coil)
GREEN to WHITE = 700 ohms + 10%
RED to EARTH = 140 ohms + 10% (Ignition pick up coil)
RED to WHITE = 100 ohms + 10%
YELLOW to EARTH = 0.7 ohm + 10%

It wont be battery or fuses as the machine will run without either of them...

[The Artist]

Thanks.

Its a leonelli system.
I also think its the stator system as there blue and brown wire coming from the rotor/magneto, is not putting out any voltage and I remember when I first got it, I say about 20v coming out or something like that. Now there is 0.1v coming out when spun over. Im looking for a working stator plate and have emailed a few ebay sellers with senda parts.

Also, my waterpump has a big leak, and I need to replace the rubber seals aswell as the gasket. Do i need to take the whole side of the clutch off aswell as it looks to be attached?

[The Artist]

oh and the readings are off quite a lot. im getting totally different numbers!

[cheekythomas]

Yeah sounds like the stator has packed up... the extra 2 wires on the leonelli you mention are on the other connector block that go to the loom... and yes they should have some voltage coming through them.

With the waterpump, is it the case thats leaking or the mechanical seals thats failed?

If its just the casing gasket thats gone you can replace it from the outside...

If the mechanical seals gone its case off time, as the seals enter from the back... theres 2 seals in front of each other.

When the first seal goes it allows water to run out of the engine via a drain hole on the waterpump, this is to save the engine from damage... if the second seal also fails (by which time its been leaking water from the drain hole for ages) it allows water into the gearbox and crankcases... which isnt good.

So if its leaking get it done asap.

[The Artist]

ok, ive ordered a second hand leonelli stator.

I will order the rubber seals for water pump. I took the outbit of the water pump off today and somehow the rubber seal behind the impeller had been damaged.

To remove the clutch cover do I just remove the bolts and it will come out. What about all the gears and clutch discs, won't they fall everywhere!!

[cheekythomas]

Haha... no all the clutch parts will stay in place... you wont even see the gearbox as its in the other side.

Just watch out for the 2 shim washers that can easily get lost, one fits on the shaft for the water pump drive, and one for the oil pump drive...

[The Artist]

ok thanks. I have ordered the seals and a gasket set.

Will the clutch cover inside be full of oil and will I need to get a new gasket for this bit aswell?

[The Artist]

i took the clutch side cover off. Oil drained out.
I did't need to take it off to replace rubber seal on water pump, i could have used a screwdriver to lever out as it is damaged already. New one can be pushed in. Anyway, now thats done, how do I get the cover back on. The kickstarter gear came out with its spring and now I don't know where to fit the spring! Any help! please