Hot Starting Problem Driving Me Nuts

Has your Voskhod broke again? Suffering dodgy Italian electrics? Post your tales of woe here. Or ask odd questions about the rear wheel spacer on a Vincent Black Widow, should it take your fancy.
moriniboy
Posts: 43
Joined: Wed Apr 03, 2013 7:59 pm

Re: Hot Starting Problem Driving Me Nuts

Unread post by moriniboy » Tue Jul 01, 2014 11:55 am

Its a Gilera Saturno.

Ive not really discussed it with him. Another friend/trained classic bike mechanic when told it was rewound by DH Day, started swearing and told me 'that's your problem', so....

supersix
Posts: 1816
Joined: Wed Feb 18, 2009 9:23 am
Location: wigan and sometimes Scunny or Louth, Lincs

Re: Hot Starting Problem Driving Me Nuts

Unread post by supersix » Tue Jul 01, 2014 8:16 pm

Can you get hold of a colourtune? You could see then if you do have a fat spark 'in the pot'

Coxy
Posts: 202
Joined: Sun Mar 29, 2009 11:05 am
Location: Sydney Australia

Re: Hot Starting Problem Driving Me Nuts

Unread post by Coxy » Wed Jul 02, 2014 9:04 pm

There can also be an issue where the spark is good outside the cylinder but under compression it simply does not work.

The old Champion sand blasting spark plug cleaners at least here in Australia had a coil setup where you cleaned the plug and then put it in the machine to check the spark under pressure of shop air at 100 psi to make sure they worked in a real world environment under pressure, So the performance of the ignition working under cylinder pressure even at 90 psi could also be the issue.

trophy
Posts: 113
Joined: Tue Jul 14, 2009 9:52 am

Re: Hot Starting Problem Driving Me Nuts

Unread post by trophy » Sat Jul 05, 2014 2:35 pm

probably a silly question but have altered plug gaps to 20 thou for mag as most modern plugs come with 30+ gaps .also do you feel to have same compression hot and cold when kick starting .?

Coxy
Posts: 202
Joined: Sun Mar 29, 2009 11:05 am
Location: Sydney Australia

Re: Hot Starting Problem Driving Me Nuts

Unread post by Coxy » Mon Jul 07, 2014 11:13 pm

Whilst the piston and rings will expand when hot so to does the Cylinder,But another aspect not addressed is that Electrics not to mention Electronics are renowned for variations under increased temperature.

As owners of modern Bikes know all too well Pulsar coils fail when hot and often will restart when they cool down, Why not with a magneto coil, a good test in that regard would be to test the resistance with a Multimeter when cold and then use a hairdryer to heat up the Magneto and retest the resistance hot to see what change occurs for there will be a change and more than likely in a direction causing your hard starting issues.

Pete R
Posts: 81
Joined: Sat Jul 07, 2012 8:04 am

Re: Hot Starting Problem Driving Me Nuts

Unread post by Pete R » Tue Jul 08, 2014 10:38 am

Even simpler hot spark test is the spark plug gapped to 5 mm , like I already advised.
If the spark can jump the 5 mm gap in atmospheric pressure when the mag is hot, there's no spark problem.

User avatar
SMIFFY R
Posts: 1792
Joined: Tue Mar 03, 2009 10:17 pm
Location: Camargue,South of France

Re: Hot Starting Problem Driving Me Nuts

Unread post by SMIFFY R » Tue Jul 08, 2014 11:40 am

I had a Triumph that had that problem with the mag,when the mag got really hot it would drop onto one cylynder then would cut out on both,after a bit of a rest(fag break)it would fire up okay then the same performance some miles later....met some nice people who stopped to help tho :)
Go to Heaven for the climate....Hell for the company

moriniboy
Posts: 43
Joined: Wed Apr 03, 2013 7:59 pm

Re: Hot Starting Problem Driving Me Nuts

Unread post by moriniboy » Tue Aug 05, 2014 11:17 am

WELL WELL...another exciting episode. My vintage-bike mechanic mate checked the bike over, said 'its got to be the Magneto' especially, apprently, when he heard who'd "rebuilt" it before. He took it off, has given it to a different mag specialist, who in under a week, not the 2 months it took previously, says the condensor -which i must confess I didnt even know the Marelli mag had secreted away inside- is the original Marelli one and clearly hadnt been replaced for his £400 fee. I presume I cant say on here, who'd "done the work" before, but you will have seen his ads here in the UK in OBM etc, and lets just say you wont find him AT NIGHT

User avatar
SMIFFY R
Posts: 1792
Joined: Tue Mar 03, 2009 10:17 pm
Location: Camargue,South of France

Re: Hot Starting Problem Driving Me Nuts

Unread post by SMIFFY R » Tue Aug 05, 2014 11:44 am

If you've spent 400£ for poor service and are pissed off(I know I would be)..why not name and shame the bastard in the "Comments section" on here?..that way it prevents others from also being "stung" ;)
Go to Heaven for the climate....Hell for the company

moriniboy
Posts: 43
Joined: Wed Apr 03, 2013 7:59 pm

Re: Hot Starting Problem Driving Me Nuts

Unread post by moriniboy » Tue Aug 05, 2014 11:54 am

Just have Commented. It was DH Day of Wroughton Wilts, who sadly I gave a Norton 18 mag (and £400) to recently to do.

Post Reply