I need your help once more.
I cannot understand why my machine doesn't start while cold. When I push her down the hill where I live, she starts even if with a bit of difficulty.
Then for the rest of the ride, being hot, she starts at the first kick.
When you get home, turn the fuel off and starve the bike rather than using the decompressor.
The last few revolutions the engine will be running very lean so it tends ti burn the crud off the plug.
You might need to go up one hotter grade of spark plug.
Are you flooding the carb and what is the idle like? If fiddling with the pilot airscrew makes little or no difference to the bike's idling, and if that idle is lumpy you may have a worn float needle/seat meaning the bike is running excessively rich. It was a problem on my 16h, cured by fitting a plastic float and new needle. If when you shut the petrol off the idle starts to go faster you're running rich. If you are using an NGK that may well be your problem. The quality has gone through the floor since they have been made in China. Try a Bosch or if not in keeping a Champion. Just because there's a nice spark outside doesn't mean it works under pressure, and remember spark plug gap is less on magneto driven systems.
Thank you Jeremy. Will change my spark and try in this way as well.
Keep you posted.
Yesterday I did a nice ride up and down the Alps. 75 miles. It took three hours :slightly_smiling_face: and the bike run well. Only she vibrates a lot...I have to go to my dentist to put the fillings back:joy: :joy: :joy:
When you get home, turn the fuel off and starve the engine.
In the final 30 seconds the engine will start to run lean so will burn any deposits off the spark plug so when you go to start next time there is no carbon build up on the plug to allow it to short out.
I find I have to do the same thing if the engine has been running for less than 15 minutes.
And yes, the new plugs are not particularly good.
Back in the day when they were good, they costed about 2 hours pay.
Now days that is closer to 1/2 hours pay.
Something has to give and what does is quality.
Modern plugs have no glazing on the porcelain insulator. When you enrich the fuel for cold starting unless it fires quickly the fuel soaks into the porcelain and shorts out the plug. Modern vehicles don't have the problem as with the metered fuel injection they fire almost immediately. Try and source some new old stock plugs at jumbles as I do.
Well, I checked the timing ... once again... and found she had less problem but still difficult to start. I changed the plug and finally have fixed it.
Thanks again to everybody for the tips
Cheers from Italy
