Trying to set the timing on my 85 12a I can set the timing on my leading by turning the dizzy body, but when I try and adjust the trailing by undoing the 2 screws & move it nothing happens, any help??????
Thanks

 

I assume you hooked up the timing light to the trailing when you did this? I forgot and left it on leading once, took me forever to figure out what was up.

 

Yes I did............

 

I also noticed something. I lined up the yellow mark & lined up the dizzy & put it back. I then marked the dizzy, if you move the pully around 360 to line up the yellow mark again the dizzy does not match the marks I made???

 

the dizzy rotates 1/2 a time for each engine rotation.

 

Just took a look at mine. Takes 2 turns of the crank to move the dizzy 1. So you are fine there. Is it possible you lined up the lead plug on the trailing mark? I use a light with a built in advance which helps me see both marks if I need.

 

Just to make sure on the pulley the bottom mark as you look at it is the lead same as the bottom plug is the lead

 

Yep I got that. actually I have 3 marks 20before 0 20 after, just cant get the trailing to move no matter where I lock the lead in. could the vacuum piece for the trailing be broken? I do have spares.

 

Anything is possible. Pop the cap and take a look its in plain view.

 

which of your timing marks are you using for the lead? It should be the middle one.

 

Take a look inside the dizzy and make sure the linkage is still connected between the vacuum pot and the magnetic pickup. You should see the pickup move when you adjust the vacuum pot.

And crankit, you probably know this but when using an advance dial to set the timing on a rotary you need to dial in twice the amount of advance you actually need.

 

Thanks guys for your help i'll check, I think I may just try dropping in the old dizzy from my previous engine, that I know worked

 

Thanks to REVHED on the timing info was told earlier also

 

with nothing to do till my 12a cooled down I was surfing through old posts re hot start problems, & tracked it down to the hot start assist, I disconected it & now it will start even when hot.......1 DOWN
Back to my original timing problem I have noticed that when I hook up the timing light to the trailing plug, the only thing that will move the marks is by turning the dizzy body, !!!!!!!! do I have the leads from the coils hooked up wrong
dont want to switch in case I damage something.
many thanks.

 

just checked the Haynes wiring diagram (should of done that before posting) I do have the wires from the coils mixed up.