i got this on my 02 m750. checked the valve clearances ,they are good. balanced the throttle bodies.
idk where its coming from?!? ???
http://www.youtube.com/watch?v=XaxPerKyaw8
my fcr41's do that on the 99 m900 a bit. lots of gas is what i thought it was from
Quote from: j v on May 21, 2011, 01:33:44 PM
my fcr41's do that on the 99 m900 a bit. lots of gas is what i thought it was from
so what was it?
preignite belch
What are the valve clearances?
Quote from: Speeddog on May 21, 2011, 03:04:36 PM
What are the valve clearances?
intake opener 0.003
intake closer 0.004
exhaust opener 0.005
exhaust closer 0.005
Those closers are loose.
I bet that with the closer clearances at 0.001 it won't be backfiring.
Quote from: Speeddog on May 21, 2011, 05:18:04 PM
Those closers are loose.
I bet that with the closer clearances at 0.001 it won't be backfiring.
+1 - I had the same problem; went away with a valve adjustment
Quote from: Speeddog on May 21, 2011, 05:18:04 PM
Those closers are loose.
I bet that with the closer clearances at 0.001 it won't be backfiring.
thank u! i ll get the micrometer today and measure the shims. then i ll order new ones! should i replace the openers as well? what do u think?
Nothing wrong with the openers where they are now, but they may tighten up a bit when you get the closers fixed.
That's not much of an issue, it's easy to make shims thinner.
Quote from: bergdoerfer on May 21, 2011, 06:08:55 PM
+1 - I had the same problem; went away with a valve adjustment
i hope it will go away when im done! [thumbsup]
did u have loss of power while riding as well? for example : doing 80mph on 5th gear and out of nowehere feeling one of the pistons not working.. and the power dropping?
ok , so i replaced the shims.. 0mm clearance on the closers and .10mm on the openers ..
the intake backfire is still there.. i dont know what to do .. please help..
my season is ruined.. [bang]
Quote from: svp88 on May 29, 2011, 02:49:09 PM
ok , so i replaced the shims.. 0mm clearance on the closers and .10mm on the openers ..
the intake backfire is still there.. i dont know what to do .. please help..
my season is ruined.. [bang]
Any update on your situation?? I would be interested to hear the solution if any.
Quote from: MaaloX on June 28, 2011, 08:19:31 PM
Any update on your situation?? I would be interested to hear the solution if any.
sorry i didn't post anything for so long...
the solution : the intake backfire is caused from the throttle bodies.. as i said previously i adjusted the valves but it was still there...
its all on the throttle position and throttle bodies... all i did is: set up the idling at 1100-1200 rpms and balanced them with my homemade manometer.
since then the intake backfire went away.. it only happens if i downshift from 2nd to 1st and i open up the throttle REALLY fast. (i know i didnt do 100% throttle body adj)
i ve done more than 500 miles since then with no problems. no loss of power Nothing!! last week i removed the spark plugs right after a 50mile ride to see their color .. i was surprised , they were light gray and DRY! unlike before *black and wet. thats it so far. i will have to do the vertical cylinders valve adjustment soon because on 5-6k rpms i get this weird vibration on the bike ...
thats it so far .. i was scared my summer was ruined but i was mistaken.. thx to everybody here im out there riding... thank you all [thumbsup]
Quote from: svp88 on July 05, 2011, 05:18:00 PM
its all on the throttle position and throttle bodies... all i did is: set up the idling at 1100-1200 rpms and balanced them with my homemade manometer.
svp88, I think I have this exact problem. Unfortunately, I don't really understand what you did in your description above. Any chance you might be able to elaborate a little? Sorry, I'm pretty new. Thanks!
Dan