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carburetors
Posted: Wed Dec 16, 2009 4:32 pm
by atheos_mb
Hello,
I am starting a new topic cause posting in my old one would be off topic
NC23 RRJ
Got this old bike that didnt start and my goal of course is to make it run again
Bike now starts but the sound is a bit odd.I have removed disassembled the carbs and then assembled.NONE of the settings have been messed up cause I didnt touch them
The only thing I did change beacuse I didnt know,were the idle screws.
My problem is that carburetor #1 does not work hence the odd sound.
a ) carbs 2,3,4 do work cause when I place my hand on the intake I can feel the vacuum,on #1 I feel nothing
b ) gasoline overflow from 1&2 T-connection.
c ) When revving #1 "seems" to respond due to the fact that the needle lifts up
ANY suggestions or ANY hint would be appreciated
Thank you in advance
Re: carburetors
Posted: Wed Dec 16, 2009 4:34 pm
by atheos_mb
I would also like info on how to synchronize the carbs
Links,pdf,or guides,anything is appreciable
Thanx
Re: carburetors
Posted: Wed Dec 16, 2009 4:43 pm
by w00dzy
I would check that you are getting a spark on the carb that isnt working..
You will either need a carb sync kit or you could make one that would be reasonably accurate...

Re: carburetors
Posted: Wed Dec 16, 2009 5:08 pm
by Waza4
You need to go by the exhaust header temperature to tell which is not running.You can still get a vacuum even if its not firing because its the piston sucking the air in.
I use the Morgan Balance tool its very good,but you can use feeler gauges to get a rough base setting.
Have you got a spark?
Re: carburetors
Posted: Wed Dec 16, 2009 7:12 pm
by atheos_mb
I do have a spark on all cylinders,I cant tell myself if the brightness or the color of the spark is correct so I brought a friend.He tells me all the sparks are ok
Re: carburetors
Posted: Thu Dec 17, 2009 12:12 pm
by greggo
Is there fuel in the float bowl of number 1?
Is it possible the leak between 1 & 2 is causing number 1 to have limited or no fuel flow? Not sure if such a thing exists but it could be worth separating number 1 and 2 and replacing the seals on that t-junction to stop the leak (i presume it is from the seals).
Eliminate the obvious defects first.
The slide on number one would not move up (needle lift) unless there was a vacuum, so i'm not sure what you mean by feeling no vacuum on number 1? No vacuum would mean no cylinder pressure. Does your carb manifold have a crack, hole, or potential to not seal?
Re: carburetors
Posted: Thu Dec 17, 2009 7:29 pm
by atheos_mb
Although I did disassembled and assembled the carbs,for some reason #1 float bowl could not move freely.After fiddling with it(take out the pin and then inserting it in again) carbs are now working.I can feel vacuum from all carbs and the sound now is better.
Greggo
I am starting the bike without the airbox on and when i place my hand on the carbs air intake i feel vacuum
All O-rings have been replaced when I first disassembled them.No leak from there
As for the crack,the intake seems solid.
Even now that the bike sounds better I still have gasoline coming out from the overflowing hose when idling.when revving up no overflow.The overflowing hose between carbs 1&2
After the shutting off the engine and moving the needle up,I noticed that on carbs 3&4 the butterflies are "dry" while on 1&2 there is gasoline
Please keep in mind that the carbs are not idle synchronized.<-----Am giving you all the info I have to help me
Thank you in advance