air intake ????

[Timothy]

this is the problem,
engine starts on choke,it will happily idle and sounds very "Sweet" with the  idle speed,mixturescrew and distrubutor adjusted(im no master of what appears to be a very delicate black art,just trial and error and trusting my ears!)  but still stalls when revved",i assume the electrics are fine or the car would not run well on idle,is this assumption correct? also i have cleaned and checked the carburettor,and it now appears i can get the car to rev with a rag held over the air intake,but will stall with out, and have also notice air bubbles in the fuel line,could these air bubbles be  the cause of the problem,also the air intake has been disconnected and a small k&n filter fitted instead,the black plastic "biscuit tin" original  has been removed and the hole blanked off and all bolted down with lots of shiny new bolts.would the tin engine cover not sealing tight  or wrong size after marker air filter cause problems?,at the moment my next move will be to drain petrol replace fuel lines,and put the air intake back to how it was originally or undo all those shiny bolts and make or seal the tin ware with something before bolting back together {this would be the  cheaper option as it would cost no money}but could also be a complete waste of time,i am pulling whats left of my hair out trying to solve the problem,any advice would be appreciated,i have very little knowledge when it comes to motor mechanics,and a tight budget too which is definantly not helping!

[Hazey-n-Marc]

BIS or aircooled?

[Timothy]

should have said  aircooled x reg 1981

[Hazey-n-Marc]

Is it better with the choke out?

[midvillesb]

Sounds like a fuel rather than a mixture issue to me - I'd suggest checking 1) the fuel pump and 2) the float valve on the carb as the two most likely culprits if poor running /cutting out other than at idle.  I had similar issues, replaced the carb with a properly rebuilt unit and all problems sorted - my amateur overhaul looked ok'd but when I stripped the old carb down properly it was clear that the float was sticking.

Might also be worth checking the centrifugal ignition advance on the distributor

[bis13]

hi Tim firstly how long has the car been sitting? as it will run like a pig with stale petrol running through it, check the fuel filter if you have changed the fuel ideally fit a new one regardless. check the carb for any obvious problems in its working parts and if you feel capable remove and give the carb a quick clean up inside and check for excessive wear on the carb screw the idling mixture screw right in then withdraw it by one and a half turns.
next stop is to static time the car and then start the car it sounds like its starting and running at idle already so if you think the carb and timing is not necessary then ignore. you say you have air bubbles and when you rev the  car cuts out can you pull away or does it just die before you move? i would say that the first place to check is the fuel pump as if the car has been standing can become corroded and be full of gunk you can remove and strip the fuel pump if you wish try this first and clean it up, inspect the diaphragm if its holed its buggered (if you find it is i have a spare you can have). i doubt if the filter is the culprit as i run pretty much without one its only there to ensure that it picks out as much of the airbourne crud as it can if it is totally fouled up it could hinder running just clean it out if that is the case. hope this helps any and if in doubt you know we are all here to help or at least offer some hope! be lucky.         

[Timothy]

will try running straight from a can of fresh petrol , then bite the bullet and replace the carb,wont be able to resist buying a refurb kit and trying that first but ive given it a real good clean ans everything seemed okj,i may have to except buying a shiny new webber instead.thankyou for the advice will let you know how it turns out.

[Timothy]

fresh petrol is not the problem ,have taken carb apart again !such a simple mechanism i cant accept it needs replacing  yet, but this is taking much longer to sort out than buying a new one and bolting it in, but wheres the fun in that and what am i go to learn from the experience will soon be able to strip a fiat 126 carb blindfold :!! it seems the float is not set to the right height,could this really be the cause of all my hassel,will find out when i do some bending with pliers put the carb back together and find out,who knows might even find the time to try tomorrow!