Cam installation/timing questions

[kip]

This is likely a case of I am out in space... but just to make sure I am reading the manual correctly. I am reinstalling both cams. The manual states if both cams are out to start with the "FT" mark on the flywheel for the front cylinder, put the cam lobs down and let it rip. Seems like it would be possible to have the cams 180 degrees out and have the spark at the top of the exhaust stroke instead of the preffered compression stroke? I am pretty sure I am missing somthing here? I am obviously not clear on how the spark unit/pulse generator and whatever else figures out when to light the plugs. I am more familiar with the concept of a cam driven distributor. The pulse generator being on the crankshaft is extra confusing. Is there some magic I am missing? or how do I figure out the *correct* "FT" to start with?

[Hordpower]

It doesn't matter, the ignition is wasted spark. Just find FT, install the F cam lobes down, turn the crank forward until RT, and install the R cam lobes down. This will establish the proper firing order. (the engine fires F first, then R, if you are not careful you can create a R-to-F firing order.. big difference!)

[kip]

Yeah I already messed up the firing order, which is what prompted me trying to figure this all out.

I am surprised it wastes a spark.

Thanks JD I appreciate it.

[brewsy]

JD,
I take it youve done this?
Getting the cams wrong would simply make a single with a great big dummy counterweight (the other piston) no?
ie the back piston fires on the front signal and the front fires not at all as the spark fires when the piston is nowhere near TDC.
Sound about right?

Marc

[Hordpower]

No, the ignition timing is unaffected, since the ignition is driven via the crankshaft. If you phase the cams wrong it will fire R-F, 128 crank degrees apart. Normal cam phasing makes it fire F-R, 232 degrees apart.

It's very hard to explain.

Maybe a better way to say it: Assuming the cams are properly timed to each of their respective pistons, there are 2 firing orders possible. Wide and narrow. All you have to do is turn 1 cam 180 degrees to change the order. I've played with it, the "narrow" firing order doesn't run that great and it sounds like ass! <lol>

Hord

[joel]

I intentionally make my Hawks fire R-F - just so they sound different.Personally,I think it sounds cool - sorta a flupblup as opposed to the more familiar buppabuppa.It might run like ass but I ride like ass so it all works.I think Greg Dunn is the _only_ person to ever have been able to hear and feel the difference between it and how it should work and I'd guess 50 other Hawk people've ridden it.

It's fun is when Hawk people ask about doing mods and I let them ride my shitter that runs wrong,has too light of a spring,has what should be tankslapperiffic ride height changes,GP shift...most of em can't really put a finger on just what's different as the whole bike honestly doesn't feel like their Hawk anymore...it's not too far off the mark to say that I've ruined it really.

[Hordpower]

Heh.

[jaysun0ne]

[pikos]

My god I love the depth of information on this forum .
Hord you are the best!