250-500cc Ignition timing of '92 360 wxc

[Dauer]

So as some of you may know I've been in need of a stator and coil for my 360 since it came into my possession about a year ago. I finally pulled the trigger on a complete system from powerdynamo to replace the motoplat "mini 4" stock ignition. I decided to go with this system because it has a lighting coil and an external rotor contrary to the PVL system.

Now comes the install, which to me is slightly daunting being as I'm a complete greenhorn when it comes to ignition electrics. The kit included reasonably detailed instructions, the actual mounting of components and the wiring seems straight forward. Setting the timing on the other hand is where experience will seem to come into play, which as previously mentioned I am lacking. The rotor does have a timing mark that can be aligned with the timing mark on the stator plate so I get that part. I also understand I will need a dial indicator to set the timing, which brings me to my initial question: what is the factory setting of a '92 360? Is it the same as later 360's? I have a manual for a '99 which states factory timing at 9° (0.6mm). Does the 0.6mm indicate the distance BTDC?

 

[rancher1]

I am not sure of the timing but you should be cautious since the 93 and later were kokusan and yours was motoplat.

 

[juicypips]

Yes its before tdc. As the spark needs to go off as the piston is naturally returning down the cylinder and 9• seems about right for the husky.

 

[Dauer]

I am not sure of the timing but you should be cautious since the 93 and later were kokusan and yours was motoplat.

Yes, valid point. That had crossed my mind that later 360's had different ignitions and could differ in timing.

Yes its before tdc. As the spark needs to go off as the piston is naturally returning down the cylinder and 9• seems about right for the husky.

Ok, thank you. Now that I think about it, by definition any piston position other than TDC would be below. How does that saying about stupid questions go? What I meant to ask is if that measurement of 0.6mm is taken with the piston on the down-stroke? Which also seems an obvious answer because if the ignition fired when the piston was on it's up-stroke it would be detrimental to the production of power and longevity of internal components. Bear with me...I'm getting there

 

[Darrel78]

Actually you want the spark (ignition event) to occur as the piston is traveling up. BTDC is before top dead center. This is desirable as to take care of the time it takes for the combustion process to begin. The ignition event begins a combustion cycle where you have an ignition of your fuel / air mixture and a traveling wavefront of expanding gases. Take a look at juicypips' picture of the carbon residue on his piston and you can get an idea of what's going on. BTDC as it takes a bit of time to get this process going. But not too far BTDC...

 

[Dauer]

Ah, I see, good to know. Not only is there a saying about stupid questions but there is also a saying about making assumptions, I seem to have covered both of those. I have a decent grasp on the actual ignition process i.e. combustion of air/fuel mixture. However it should be quite clear by now that ignition timing is not my strong point. I've read of experiencing an issue of the bike running in reverse after an ignition swap and it troubles me. What typically causes this?

 

[juicypips]

As darrel 78 stated its on up stroke but by the time the signals gone through pick up and to spark then to ignite the mix the piston will be on the down turn.

Dont beat yourself up about anything we all started somewhere
Oh yeah and if you start a job an it takes you longer than you think never say your slow state that your being methodical!
Thats the image if me piston at 1.27mm squish i play with timing by adjusting and riding never had a dial guage just done by feel n ear.
Sure its not perfect but its perfect for me.

 

[justintendo]

the 360s also have different port timing that may have a different spec..it seems the 97ish and earlier are much different than the 98-02..perhaps a different spec as well

 

[Darrel78]

Don't get too hung up on this; a dial indicator is real nice but even a wooden dowel stick with accurate marks will serve your purpose. Keeping an eye on your goal, some value before top dead center, you can measure distance via piston travel as displayed via the spark plug or measure around your flywheel. Circumference divided by 360 is your degrees. Several articles on the forum on this subject. Easy to do.

 

[juicypips]

Hell im gunna set my timing just for the kick now. Cheers for the tip

 

[2premo]

most bikes run in a general range of a few thou. or a mm
my 430 is 1.9 my 250 is the same and they share an ignition
don't get too bogged down a couple mm BTDC and try it if it seems flat advance it, if it sounds aggressive and or pings retard it

 

[Dauer]

All great info and advice. It's funny you mention using a wooden dowel because a guy at my local motorcycle shop said the same thing. Hollow out a spark plug, thread it in, insert the dowel, verify TDC then go from there. Sometimes I get hung-up at every minor detail when I'm tackling a task I'm not very experienced in because I'm unsure which details are imperative and which have a little wiggle room. It seems to me that a flywheel puller (the Husqvarna puller doesn't work with the powerdynamo rotor) may be more beneficial than a dial indicator because I doubt I'll nail the timing at first crack.

 

[juicypips]

Yup need a flywheel puller for sure, well my bike rips so will tinker with timing see if i can improve anything.
After all it only costs me time.

 

[Dauer]

Just spoke with the always helpful folks over at Hall's and inquired about the factory timing for my bike. They informed me that it is 1mm or .040" BTDC. Gonna start with that and go from there. Thought I'd share that info with you all.

 

[justintendo]

just placed another order with them myself!

 

[Dauer]

Nice! You can't beat 'em!