question on how to measure the valve shims

[Howie]

no nothing came out from the intake that day... and i left the pump there for 30min or so without touching it .. while i was doing smth else.. and when i unplugged the pump from the hole there was the same pressure .. the air came out from the spark plug hole. yes, i ll check the injectors this weekend. i was thinking to swap them with each other see if it is an fuel injector problem .. is that ok? if i swap the injectors? (put the vertical cylinder fuel injector on the horizontal and the other way around) i dont think smth will be wrong by doing that? or is it?
what did u mean by this: Oh, your bike would be would be a Ducati first, but a severely worn (more than enough to detect by eye) exhaust cam lobe could cause that symptom. 

 

Swapping injectors is OK.  By a Ducati first I simply was referring to possibility, I've never seen nor heard of this on a Duc. By more than detectable by eye I meant the wear would be so severe measuring tools would not be needed.

[desmodoktor]

ok , it looks like the intake backfire is solved... not 100% sure yet..
just got back from my garage .. worked on the bike for few hours..
Work performed:
swapped the injectors .. (it looked like the backfire was gone... but it didnt make sense .. if it was a bad injector why wouldn't backfire from the other intake? )
so i started balancing the throttle bodies with my homemade manometer....  at some point it backfired just a bit..
for some reason i started inspecting the throttle bodies.. looking for smth wrong.. idk what!!   so there it was ..  all of those adjusting screws had some type of melted plastic on top except for this one in the middle of the throttle bodies.. somebody had scratched it off ... and the spring was lose ..  thats the only thing that looked ``touched``  so i decided to tie it more.. while tying it the rpms started going up .. (there i remembered that i read someones post here abt his monster being happy idling on 1100rpms.. ) mine was idling on 600-700rpms..
left it at 1000rpms .. started revving the engine 4k-6k.. holding it steady at 1500-2500rpms  (this was the point of the backfire through intake) played with it for 25min .. no backfire ..
adjusted the throttle bodies with those 2 idling screws .. they look pretty balanced.. on idle and up to 4k rpms..  2morrow i ll put her 2gether and take her for a test ride.. 
i know ya all will laugh at me for making such a big deal abt it and all i had to do is rotate a screw 4 times.... but u got to understand that i have no experience on engines.. ( theoretical or practical) .. just trying my best to get it done..
i thank you all for your helpful answers..   

i ll post after the ride 2morrow.

[desmodoktor]

back from the ride... everything good.. no loss of power and not much of intake backfire.. in 6-7 hours ride .. it backfired maybe twice from the intake when i dropped 2 gears and and rolled the throttle very fast.. 
i have a weird question.... does atmospheric pressure changes the way the engine runs? now that im thinking .. ive lost power on the same road at 7140 feet above the sea level..
where i was riding today was 2-3 feet above the sea level .. and i didnt have the loss of power... i know this question might be stupid to ask but i thought id give it a try..

[Howie]

back from the ride... everything good.. no loss of power and not much of intake backfire.. in 6-7 hours ride .. it backfired maybe twice from the intake when i dropped 2 gears and and rolled the throttle very fast.. 
i have a weird question.... does atmospheric pressure changes the way the engine runs? now that im thinking .. ive lost power on the same road at 7140 feet above the sea level..
where i was riding today was 2-3 feet above the sea level .. and i didnt have the loss of power... i know this question might be stupid to ask but i thought id give it a try..

Yes.

[desmodoktor]

Yes.

thx howie!