Throttle Lag

[Lucky_Lou]

Im still getting a bit of throttle lag when i accelerate ive set the floats and adjusted the cables which has improved it a bit ...is it just a case of adjusting the air screws or aything else worth tweeking.
 TaLou
ps the sun shines in the yorkshire industrial desert

[montmil]

Good looking scooter, Lou.

Believe the stock position of the air screw is 3/4 turn out from gently closed. Check your current air screw position and try something different. Minor tweaks may help.

Also, You didn't mention throttle position during the lag during acceleration. The jet needle and needle jet are the major players until WOT at which time the main jet is the primary fuel delivery.

I would not suspect the slide cut away unless you've made a change.

Check the pilot jet for clogged orfices. Four small holes if I remember. They are prone to plugging. Drop the bowl for access.

Maybe these ideas will keep you busy.

Monte

[Lucky_Lou]

The throttle is usualy about 1/4 openish due to the lack of work ive plenty of time for tweeking and rideing.
Will pull the plugs on monday to see what they are like as its just done a complete rebuild on the carbs it could be the needles (there new)
Lou
ps i would rather ride a scooter than a lawnmower(virago)

[montmil]

Have you pulled the main jet carrier and atomizer? Probably have if you changed the needle jet. Several riders have lost performance when the Atomizer is plugged and/or the surrounding tube is cruded up.

Bings are pretty simple animals. You get it sorted.

Monte

[Lucky_Lou]

Have you pulled the main jet carrier and atomizer? Probably have if you changed the needle jet. Several riders have lost performance when the Atomizer is plugged and/or the surrounding tube is cruded up.

Bings are pretty simple animals. You get it sorted.

Monte

all new i will strip the n/s er the o/s usa as it sounds like thats the one thats lagging
ps wheres denton? ive got freinds in austin and orange
( near the louisiana border)
Lou

[montmil]

Denton is about 25 miles north of Dallas. Our eldest son and his family live in Austin. I once won a chunk of money at the horse track just across the Louisiana line from Orange.   Monte

[Ed Miller]

Lou, are you used to CV carbs?  My other bike with slide carbs does seem to pick up a bit faster when I open the throttle.  On Bings the slide doesn't go up until the engine revs start to go up, creating enough pressure differential to raise the slide.  I'm just wondering if that's what you are experiencing.

[Lucky_Lou]

i must confess ive not got much previous with these i have noticed its not as bad when i have a bit of choke on when i start cold i give it full choke let it tick over a bit while i get my gear on then drop the choke (enricher)to the first notch ??1/4 choke?? for about the first half mile then Knock it off.
Before i adjusted the floats and cables if i opened the throttle in anger it would lag for about 30 seconds before power came on now if its under power ar say 50 uphill open the throttle and it goes straight away at lower speeds if i drop a gear and open up it thinks about it for a few seconds.
 Lou

[Semper Gumby]

1) One possibility is that you have the needle set too lean (too low) and need to raise them one notch (since you said that choke helps).

2)  Second possibility - Sounds like the idle jets are not working that well?  (you said 1/4 throttle thing) The idle jet is in the bottom of the float bowl in the corner.  Many people ignore cleaning this jet during a rebuild because its is not part of the carb.  (It's part of the float bowl which is over THERE on the bench awaiting the completed carb rebuild!!!)  The chances of this being plugged with crud are very good.  PUT ON SAFETY GLASSES.  Take some carb gumout or some brake cleaner and spray it into the hole in the corner of the float bowl.  A JET OF FLUID should come out the large hole in the top of the float bowl in the corner.  PLease don't look down this hole when doing this even with saftey glasses on - point the damn thing away from you!

If it doesn't ... get a single strand of very thin copper wire and look down the hole from the top of the bowl and try to unplug the jet.  You may also have to run an 1/8" (?) inch drill bit into the corner of the float bowl (not the jet) to clean out a badly gunked float bowl from below the jet.  

I have also use a single strand from a brass or steel brush to clean this jet but be careful ....  widening the jet beyond its original diameter will richen the idle circuit!!!!

Good luck,    8-)