Motorcycle Repair: 1991 DR650, cam lobes, pilot jet

Question
  I just bought the bike a week ago and rode it home. It ran fine with 9 disks in the supertrap but to loud for street use. The next morning I took it down to three disk supertrap. It was no longer responsive and seemed to be running very lean. If I reved the engine the idle would float for a few seconds before returning to idle. And it wouldn't idle at 1500 rpm like it is suppose to. It required 2000rpms just to run smoothly. I took the bike for a ride to run some of the new fuel through it. And it got to a point I'd have to over compinsate with the thottle just to get it going off a light without stalling it, and I got myself stranded. It felt like a fuel related issue. So when I got home I tryed kicking it over with starting fluid, and it wouldn't even fire or pop once to show me it has the three elements it needed. I checked spark, and it seems to have good spark from both plugs. I tore through the carb but it all seems to be in good order, and clean. And it still has its stock jets. With the exception of the pilot jet #47.5 which is smaller than the #50 called for by suzuki but pretty close. But with the stock Jets going from 9 disks to 3 shouldn't have effected it negitivly. Engine compression is good. I adjusted the valves & the manual Decomp,  inspected the cam lobes for wear and it all checked out okay.
  Now I find the fuel cock has no flow in the primary position without vacume. In the PRI-mary position it should flow freely without the use of vacume correct? The ON & REServe positions work as the should with vacume pressure. Could the fuel cock be the source of all my troubles? Although I think I ruled that out as well. I took the fuel cock apart cleaned it out. And I couldn't find the bypass that would allow fuel to pass the diaphram so I temporarly disabled the diaphram by removing the spring from beneath it to pin it open. To see if this could be the source of my troubles. And it beared the same result, So I returned it to the previous set-up. I know this part does need to be replaced but could it really be the sourse of my problems? Money is tight and I would preffer to spend it on more likely repiars but if you think the fuel cock could be it I'll get it. I've read the advise you have given others in similiar situations and would like to hear what you have to say about this one.
  Starting fluid didn't start the bike either so could my problem be in my ignition system dispite the appearance of good spark? I'm running out of ideas. Of and the air cleaner element is clean. allong with every fuel screen I can find One from above the pick-cock, and another in the inlet tube to carburator.
   I would greatly apprecieate even just being sent in the right direction here as I am feeling puzzeled.
    
Thank you,
Mathew  

Answer
Hi Matthew,

Thanks for taking the time to type the very detailed narrative. I wish others would do the same.

Cut and paste your question in a email and send it to me:

mshively1@woh.rr.com

I'll return tech files and information to help you diagnose the problem. Hold off on buying parts for now. See microfiche and parts at "www.bikebandit.com"

Respectfully,
Mark Shively