Hi,

I've got a 1973 142 with recently rebuilt motor (well, about 5000 kilometres ago), running a "fast road cam" and 2 x 45DCOE webers with 36 chokes, jets set up by the mechanic who build the motor for me. Holley fuel pump and pressure regulator, pertornix ignitor. I haven't driven it much in the last few years so I don't remember how this problem started, but I think it dates from the rebuild.

It idles fine when cold but as soon as it is warm, after revving it or driving it, it wants to idle around 2000 rpm for a while - probably up to a minute - before dropping down. I can bring it down on the idle screw, but once at normal levels (maybe 1000 rpm) it then wants to stall. Screw it back to a comfortable idle then give it a rev - and the problem returns.

I had the carbs rebuilt by a reputable specialist last week and I swapped the distributor for one with points, although I don't know how good it is. Same symptoms after that, although the idle is probably a little better.

Any suggestions? My next step is to try yet another distributor from the spares pile and maybe even different webers. I've got a brand new pair waiting so go on a different motor but I'd love some suggestions before I just go randomly swapping bits.

Oh, and it runs well apart from the idle problem.

Regards
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JohnH, Sydney, Australia