4ac problem

**pro-16t** · 23-02-2006, 11:05 PM

Got a problem, got my 4ac reco'd (i know i know) put the thing in got new plugs,leads, dizzy cap, filters & a bosch coil etc: anyway just got the motor in got her started but there is a valve on the left of the carby you can see the linkage moving in & out of the valve repeatitivly which makes her rev up & down repeatitivly.

Then i played around with the timing & idol screw that helped a little but didn't solve the problem i checked vacume lines for leaks,but she just doesn't sound right, if you stab the throttle & depress it the thing stalls instantly and its really slugish too, it used to go alright.

painted the engine bay maybe i'm not getting good earth, ballest resistor,carby ???
any help would be appreciated.

**pro-16t** · 24-02-2006, 08:14 AM

bump bump bump

**45aken** · 24-02-2006, 09:55 AM

maybe the mixture screw? (we might be talking about the same thing here thought). i know when mine was messing up the motor would turn off unless i had some throttle. the 'mixture' screw fell out and was flooding the motor whenever i backed off.

i am not sure but i think the idol and mixture screw as being the same things.

**Starfire** · 24-02-2006, 10:43 AM

The idle and mixture screws are different things.

They do a simialr job but under different throttle and vacuum conditions.

**Dale** · 24-02-2006, 10:44 AM

Sounds like it's something to do with the auto choke/ cold start idle up on the carb (not sure if 4ac's have the latter though)
Try and find and disconnect the vacuum lines going to it, there's one you can block off which will do wonders - I know it's been described before so a search might help, include the term "ball bearing"

And aren't the mixture screws capped off on those carbies due to emissions restrictions?