Ignition timing marks

[Big Fluff]

According to the shop manual, static timing on the Z1A onwards is 10 degress BTDC and fully advanced is 40 degress BTDC.
So how come the angles look equal distance between TDC, F and the FULLY ADVANCED mark
Surely the line for 'F' should be much closer the the TDC mark.


As my turbo bike needs to run at 34 degrees BTDC full advanced, with the standard advancer that would mean that the static timing would have to be at 4 degrees BTDC, whic makes it run hot low down and a bastard to start.
So what I have done is to bend the tabs in to stop the bob weights flying out too far (as indicated by the black dashed lines)
Now I'm not sure what fully advanced would now give me, but I reckon I've taken about 10 degrees out of the range.
So am I right in thinking that if I set my adjustable strobe at 34 degrees, fire up the motor and hold at say 3500rpm, set the ignition at TDC
Would this then give me 34 degrees fully advanced as I can't seem to get anywhere near this with the Dyna S backplate.
I feel I'm losing the fuggin' plot

[dazzler]

Hi i have the same problem but im told to fit a dyna 4000 programable ignition and a ajustable boost pressure swith (demon tweeks p/no LUMMPS07 £70 ) trying to sort mine in next 2 weeks ill let you know

[Pigford]

Will.....
The crutial bit is the fully advanced bit. You really need to do this 'statically'
You'll need a degree wheel & a positive stop tool.
Fit the degree wheel to the alternator side
Now fit the positive stop thingy.......... This ideally should stop the piston a bit before TDC..... #4 is OK Fix pointer to TDC on wheel. Now turn engine back so positive stop touches again.... Check reading on wheel. The difference (mid-point) is ntrue TDC Now you can set engine to xx BTDC or 34 in your case.
Disconnect #4 lead & fit loose plug - grounded on head.
Now make sure crank doesn't move & by holding the Dyna S rotor in fully advanced position, ignition switched on, get it to spark by adjusting back plate.
Easy Peasy Lemon Squeezy

[Padders]

If your stuck Will you can borrow my Degree wheel and positive stop tool.

[Al]

Will i put a see through plastic protractor on my pc screen over the image.

'F' Mark is 20 degrees and full advance is indeed 40 degrees near as dammit.

Piston speed is constant (in relative terms) however it was explained to me that the effect of transmission of the initiating voltage and subsequent discharge of spark is 'delayed' relative to the constant which is piston speed. God i hope thats right.
The effect of this is that higher rpm's need a greater degree (no pun intended) of advance.

You would therefore expect the higher advance figure (40 degree mark) to be greater than twice the distance from the TDC mark. All things being equal.

On the basis of the above i would challenge that the 'F' mark is not 10 degrees of advance but am not familiar with adv/ retards for the early bikes.
On my J Advance unit the 'F' mark is indeed considerably nearer to the 'T' mark making it much more likely to be 10 degrees of advance or the mark you see when using a strobe when on idle.

If you limit the advance range to 34 degrees by bending the tabs as you have done all you will get is 34 degrees of advance which is what you want when above 4000 RPM's.

Set the strobe to -34 ( minus thirty four) and over 4000RPM you should see a return to the 'T' mark if you have bent the tabs by the right amount.

My head is swimming now. Hope thats right.



AL

[Big Fluff]

Thanks all for the replies - Pigfords idea seems the easiest way to go.
I have a degree disc and dead stop already.

Just one final question.... With the bike on a paddock stand, will oil escape when I remove the alternator cover or is the oil level below that particular height.

Thanks, Will

[AL MARSHALL]

hi will, you will only lose a drop of oil by removing the alternator cover.......by the way careful with that paddock stand sore point eh

good to meet you and bakey at donington regs al

[Big Fluff]

good to meet you and bakey at donington regs al

Cheers Al, great to meet you too

[floydsz1]

Hi Fluf,
dont know if this will help. The rotors changed half way through the z1A production run,

http://www.z1enterprises.com/detail.aspx?ID=200