Ignition Timing - 1986 400 Enduro

[MotoFo]

I purchased a PowerDynamo ignition a while back so I can operate a more powerful lighting system for my 1986 400 Enduro. I’m finally getting around to installing it and being unfamiliar with this system, I want to be sure I set the timing correctly. First, what is the correct timing setting – 2mm BTDC? If so, how does one measure this? Anyone have advice on the proper procedure? Powerdynamo has fairly detailed instruction but I’m curious as to what others have to say.

 

[justintendo]

generally i prefer to set ignition timing via piston advance..using a dial indicator threaded through the spark plug hole. i also like to retard them a bit compared to stock spec to lessen kickback and help wear on the kickstart components.
how does power dynamo say to time their ignition? i would think if a company built in a retard function while starting you could advance the timing alot more than stock maybe. the motoplats had no timing curve/map, so what you set them at was a compromise i think for starting, bottom end, top end, etc..
with the external mini 6 motoplat i use about 1.5mm btdc on the 400/430..im not sure if that applies to a newer system tho

 

[MotoFo]

Power dynamo's guide says: "…time the ignition by setting the rotor in such a position that with the piston at ignition moment the marking on the rotor (it comes marked) aligns with transposed stator marking (the stator is marked as well) on the outer casing. …For where timing (firing) moment is, consult your manufacturers manual. Should you not have any guidance at all try with 2mm BTDC."

Looks like I need to get a dial indicator that threads into the spark plug hold. Thanks!

 

[2premo]

I run mine at 1.9mm BTDC
running more advanced is hard on parts and unless you're competing what's the point
justin, you run 1.5, interesting, how is the power at that setting, might have to try it

 

[justintendo]

I run mine at 1.9mm BTDC
running more advanced is hard on parts and unless you're competing what's the point
justin, you run 1.5, interesting, how is the power at that setting, might have to try it

maybe a hair softer bottom end hit..but winds out better. pretty small differences. no back talk from the kicker.
a 250 i will try to push more timing.

 

[visiteur1948]

 

[Eric The Leg]

Here is my suggestion:
Due to magnets involved, it is hard to precisely set your timing in one step (rotor doesn't like to stay pointing where you want it to while you torque it down), so I rough it in and then adjust.
Take out spark plug, mount your stator plate in the middle of the adjustable range, then use a simple depth gauge (i.e. not precision yet) through the plug hole to get a 'pretty good' fix on 2mm prior to TDC (basically I run the cylinder around a few times to get a pretty good feel for what the piston pushes the depth gauge to, then lock the gauge 2 mm longer than that and run around until piston touches depth of the gauge).
Install your rotor (line at dot) based on this rough measure. Depending on your risk tolerance and how you feel about your rough in, go for a ride and then torque down your rotor again.
Now you can break out your dial indicator for a finer measurement of tdc and set by either 2mm, variation of 2mm or angle for the fine adjustment.

 

[MotoFo]

Thanks for the info and specs. I have a dial indicator coming. Sounds like it shouldn't be too big of a deal.

 

[Darrel78]

I set my PowerDynamo at 1.8 mm btdc and have no starting issues. It's a huge improvement over stock for lighting.