Intresting ride!

justintendo
-if you moved it to 2.5mm you would be advancing the timing from your stated 2mm btdc. if you are not experiencing kickbacks, you could leave it as is.
-what do you mean, "race set up of 1.9mm"? the more advanced, the more response, the more stress and octane requirement. a "race" setup would be book spec or perhaps even more advanced..
-how are you measuring timing? in my 400 and 430 i have run 1.5-1.8 with little or no kickback.

-my bad, I meant advance to 2.5
-the 2.3mm btdc was the only info I could find on timing. It was for an 87 430 and the 1.9mm btdc along with some jetting specs were listed. I'll post it can find it again
-used a dial indicator to fid tdc, marked flywheel and engine case, backed flywheel until indicator showed 2mm then 3mm and marked both positions on case opposite flywheel mark. Started bike and hooked up timing light. My flywheel mark lined up perfectly with 2mm mark.....hope you got that.

BTW
Todays ride had no kickbacks and once up to temp started first......usually if I didn't give it a girly kick.

Crashaholic
The further away from TDC you move the timing the more difficult it becomes to start and the chance of kickback increases. According to my data your 2.00mm setting is spot on. There are other conditions that can cause the motor to pop and subsequently turn in the opposite direction. Whether its enough to ignite the motor in that direction is another thing but possible.

Some of the things that come to mind begin with a slow piston speed from a weak kick start which are then combined with one or more of the following: a lean condition due to an air leak, low octane or old fuel, near empty carb bowl, intermittent sparkplug malfunction, ghostly spirits (sorry, I couldn't resist that one ).


Think it was a wimpy kick.......getting use to the leftkicker

the 430 and 400 have the same porting and port timing...so the ign timing should be real close. i take it you dont have the motoplat that lets you use the pin? even if you have the sem, you wouldnt have to use a strobe but i think from your description you are timing it ok.
i personally like using the dial indicator. you can even back the timing to 1.5 and be safer..sounds like you have it set up ok tho.
you are correct, the more advance the harder it is to start...but you lose a bit of throttle response. no big deal on the 400/430/500, its worth saving the mechanicals and your body..plus the bike pulls a bit better up top with the timing a bit retarded.