A friend of mine has a 1600 with L18 and twin 45 Webers - he just got them turned which involved putting in smaller jets (the ones in it were oversized apparently - used to fuel up a lot) etc.

Now it runs great but between about 1900 and 2200 rpm the carbies make a kind of 'spitting' noise - what is this caused by? I have been told that it might be because they are running lean at this revs - could this be the reason?

Thanks for any input.

Spit back is usually a sign of a lean mixture, so he may have gone a bit small on the mains (or they may be OK but now it needs some richening on the transition, etc). Take it back and get them to look at it with an ex gas analyser which should pick up the problem. Note that this problem can also be caused by inlet manifold air leaks.

might also be timing? my timing is way out and it spits flames when the airfilter is off, its actually kinda kool as they are like 3 foot high ones, should really sort it out when i put it on the road.
but if your mates just got it tuned then its most probably NOT timing.

My guess would have been timing - if its not and the carbs have just been tuned properly you may want to look at cam timing....

If the engine has had some work done and the head/deck has been machined the cam timing might be out a smidge. unlikely but it happens.

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Thanks for your input and advice Steve, dattohoe and Rivmasta.

I will get him to take the car back to where he got it tuned as I now understand it should not be doing the spitting thing! I think its more due to the mixtures rather than timing, you'd think the mechanic would have at least got that right ... ah well...

Thanks again,

Charlotte