Finally have the freshly built JTS A15 hooked up in the 1200. But i am getting some starting problems. Symtoms are backfiring out carbys. I am assuming its an ignition problem - timings out. I advanced the dizzy right up - same problem - carby backfiring. The dizzy is an electronic unit - modified pulsar N12. My main concern is whether i've re-installed the dizzy on the correct tooth - do electronic ignitions sort themselfs out or do i need to sort out the alignment??

Any help appreciated!!

Carby backfire usually means lean mixture condition. i assume you have twin sidedraughts attached

no you will need to set the timing again.

without a timing light the only way to do this is to turn the engine over manually until you reach about 15deg btdc (what you will most likely need to run on this engine) on no.1 compression stroke. remove dizzy cap and align the contacts so that it's firing at that point.

ensure that you have the plug leads on the correct terminals. remember that the dizzys spin anticlockwise on the A series. 1-3-4-2...

Sounds like its too lean on idle as benny said. whats your idle rpm and base timing? Should be around 14-16

The dizzy may also be incorrectly aligned if you did it youself so check that .

Twin webers are great for backfiring when not tuned to within an inch of their life.

Hi davo long time no see I havnt been online for ages. My bet is that the dizzy is 180 degrees out I have done the same thing once before with simaller symptoms.
Cheers Andrew

Quote:
yep my bet to same problem with my gx it has a elec unit

When i mean backfiring i mean at start-up not at idle - i cant get it to start at all. Has twin 45 webers. Doubt its lean.

Will have another go at setting the dizzy manually tho...

Andrew! Has been a while! The A14's looking good! Just need some spark at the right time lol! Fingers crossed!!

yeh it would be the dizzy 180 deg out same thing with my gx had it set up "right" would just keep winding over then bang it would backfire and so we were wondering what was going on eventualy concluded it was sparking on the wrong stroke and so we swap the leads around so it was 180 from where it was and tryed it started up fine

the same thing happened on my a15 wouldnt start just fired through the carby had to chang the leads to the firing order and it was ok