Hard to start

[AndyCocks]

Hi ya my early strada is a pain to start if it does l when cold. The spark at the plugs is not very bright at both plugs.
Have measured the resitance through the stator coil (green wire at fuse box) I get 220 ohms and a voltage when kicking it over( no electric start) of approx 9v AC.
Any suggestions? It’s got new plugs non resistor, I’ve replaced plug caps (NGK with 5kohm resistance) and new copper core leads

[MickeyMoto]

Where did you measure the resistance? To the engine or the frame?

Did you disconnect the wire from the generator to make the measurement?

It could need the magneto rewinding.

[AndyCocks]

Thanks for the reply measured to the frame and also engine, both the same. Also wire was disconnected at the fuse box.

[George 350]

Try cleaning all connections on the green wire between generator and transducers and try it. Leave it off the ignition switch as an extra measure.
I will say 9v sounds very low, so am wondering if your rotor needs remagnetising?
Other things to check:
Resistor plug caps?
Resistor plugs? Either/both of these will not help your problem.
You could try a smaller plug gap, but if successful, that would only be masking the real issue.
Let us know how you get on.
Regards,
George

[mbmm350s]

Hi Andy,
All good suggestions of what to check so far.

Are you still on the original 40+ year old transducers?
they do degrade with time, like any coil does, The proper way to measure the spark is that the spark should jump 5mm in air from the end of the bared lead.

Later "bulged" type transducers (either for red pick up or black pickup) pack more turns, so more volts and bigger sparks.
These you can get from Alex Luzzi.

Mark

[70sbikes]

I run my transducer earths to the motor, as I found the frame earth point kept going rusty...

[AndyCocks]

Thanks for the replies, I going to have another look when I get a chance. I going to take the flywheel off and while doing so will change the cambelt.

[norbert]

Take the spark plugs out, conect a Multimeter to the green cable coming from the alterator (AC voltage to ground). Sit on the bike holding it firmly on the center stand, 2nd or 3rd gear. Now a friend that have have had a good breakfast schould turn the wheel in direction of running. You should measure anything about 70-100 V (AC!). If not and the resistance of the coil (green cable from the alternator) is 220 ohm, to me that smells like a very bad rotor.

With only 9 V I would not expect any spark at all

[AndyCocks]

Got the r/h side cover off tonight and removed the flywheel with puller, whilst it’s only a problem when checking ignition timing the woodruff key is missing!
The stator doesn’t look bad but was going to get it checked (any suggestion?) magnets strength seem
Ok. Thanks

[norbert]

You should put that woodroof key, before doing anything else, because if the flywheel is not in the corect posicion you can not use the marks of PMS and ANT and will loose the valve and ignition timing.

[AndyCocks]

Got to the bottom of the poor starting. After taking the flywheel off i took the stator plate off and sent it to Westcountry Windings in Thetford who rewound the ignition stator coil for me at a cost of £94. Put on tonight and it starts. Just need to finish refitting the covers over the weekend.

[MickeyMoto]

I claim my prize!