how to fix decel popping?
#1
how to fix decel popping?
I just installed a full muzzy and rejetted. Bike seems to run good. It has fine acceleration through out the rpm range except the bottom end feels a little sluggish(it may be just how the bike is, I am not sure.) Under normal riding decel poping is minimal altough I don't really down shift and high rpm. When going down a longer hill it will pop pretty much the whole way. I have the full muzzy system, backfire screen removed, twinair filter, no air box lid, breather drilled to 3/8, slide drilled, for jetting I have a 135 main, NT1C needle in third position, 40 pilot, fuel screw 2 turns out. I am about 700' elevation. Should I go back in and adjust something for the decel pop or leave it alone. Would adjustinganything help to get some more snap off the bottom(I do have a 13 tooth sprocket) or do i live with it until I get a pumper. Thanks.
#2
RE: how to fix decel popping?
Do you need the choke to start the bike when it is 60-70 degrees outside? Is it slow to warm up to where you can crack the throttle and it won't stutter? If so you might want to slowly turn the air screw out further. I was at 2.5 turns and it didn't pop at all but at the same time it would almost die at stop signs because the idle would drop so low. I went back to 2 turns and the idle is spot on always, brisk up through the revs but if I run over 6K and back out of the throttle it pops quite a bit. I need to fiddle with it some more but I'm pretty happy right now.
#3
RE: how to fix decel popping?
with the stock carb i couldn't get rid of it. try a shimming the needle. that might help. also make sure you don't have any air leaks at both ends of the carb also check the pipe at the head and at the mid pipe joint. air leaks can cause the popping. you may need a larger pilot jet but i would mess with the air/fuel screw for awhile before i went thatroute.
#4
RE: how to fix decel popping?
I still need the choke to start, but can turn it off almost right after it starts. I have the kouba fuel screw installed. When idling I screwed it all the way in and then back out to 2.5 turns out and made no difference in idle no matter where the screw was at. It does seem to idle good and doesn't seem stumble when trying to find idle.
#7
RE: how to fix decel popping?
I've always heard that popping indicates a lean condition, but that is not always the case.
Before my big bore upgrade, I believe my jetting was very rich (judging by the coloring of my piston and spark plug).
Yet I still had lots of popping on decel... Go figure.
Before my big bore upgrade, I believe my jetting was very rich (judging by the coloring of my piston and spark plug).
Yet I still had lots of popping on decel... Go figure.
#9
RE: how to fix decel popping?
we have been around the 70's maybe mid to low 60's in the morning. Humidity has been realitivly low. I went half of a turn out (to 2.5) while on the streets tonightand it seemed to run worse so I went back two 2 turns out. I don't have a problem going back into the carb, but I have very little experiance with carbs(this is the first one I have gone into) so i don't kow what to change. I have a 138 and and 140 main. Should i try the 138. Here is a dumb question to be asking now but when you put the brass collar on the needle it does go on top of the e-clip right? I could also bump the needle another slot but i already put it on positon 3 number 4 seems a little high.
#10
RE: how to fix decel popping?
air is less dense at higher temps
the hotter it is the richer you run
your temps are very moderate, probably not your problem
your pilot jet, the 40 is only for your idle circuit
you said at idle you are running fine
i would change your main jet to the 138 if you are running the 135
and leave your screw at 2 turns for now
keep us posted i would like to know your outcome
salue
the hotter it is the richer you run
your temps are very moderate, probably not your problem
your pilot jet, the 40 is only for your idle circuit
you said at idle you are running fine
i would change your main jet to the 138 if you are running the 135
and leave your screw at 2 turns for now
keep us posted i would like to know your outcome
salue