Mechanical advance springs?

[dardoonk]

Any ignition experts out there??
I understand how they work, but I have questions about what the effect of modifying them would be.

Is it possible to change the springs to allow the advance curve to come in faster or slower? Say for example you want the advance to come in at a higher RPM, would you need stiffer springs? How the heck would one go about getting them?

What would be the difference in changing the springs or adding weight?

Is it possible to increase the total advance overall. For example, another 5 degrees so you could retard the ignition a bit at lower rpms, but still reach full advance at higher rpms?

Is all this a waste of time & just get a Dyna2000??? A lot more money though

[blowerbike]

removing a spring will get you full advance sooner but may make the valves rattle....
same goes for lighter springs.

a dyna 2000 would be a nice touch.
depends on what your looking for and what you want to spend.
the factory advancer won't get you what the 2000 will.

[dardoonk]

motor is advancing too fast now, so it sounds like I want heavier springs. I want full advance to come in later. Any idea where/how to get heavier springs to slow it down

[GregT]

How do you know it's advancing too fast now ?
What are the symptoms ?

I run my race 450 on 38 deg advance Fixed - and it starts and idles well.

back when car engine builders didn't have electronics to fall back on there was a lot of playing with advance curves built into distributors. Some of it was done by varying the weights some by different springs. personally I'd play with the weights - easy enough to drill them and add small nut & bolt additional weights.Or just drill to lighten which is the same as heavier springs.

[trippivot]

YES waste of time YES waste of money

springs are rated by diameter of the wire and length of the coils.

get a thicker - same length set of springs from ace hardware - if you must.

and a fixed advancer at 38 degrees good self starting and good idle?? NO - NOT in my experience!

when you fix it at full advance you must raise the idle to 2000~2400rpm because any lower than that and you are making your own detonation/pre-ignition situation... just like hitting the piston crown with a hammer WAY before top dead center. OR trying to make the engine spin backwards.

advancing the spark is a matter of allowing enough time for the combustion flame front and expanding nitrogen to gently push the piston downward and keeping the crank in a forward moving fashion-

I can offer many performance / reliability options about altering the ignition if I had more information about your engine/ use of said engine.

[Graham]

Are new OEM advance springs still available?

[rapidray]

The only springs available are the ones that come ON the advancer & they are part of the advancer assembly, NOT available separately. Also, what makes you think you have full advance too soon? Every engine I've ever built, we want the advance in as SOON as we can get it. It makes more torque & moves the bike better. Ray.