I'm finding my wagon, with Mikuni's, is simply not as well-mannered when cold as my sedan with SU's; it doesn't matter what I do with the carbs, increasing the richness any further leaves the car running too rich when fully warmed up.

Perhaps I'm expecting too much; the last time I drove a carbed vehicle with something other than SU's was over 20 years ago, and I recall having to let it (74' Ford Econoline with 302) warm up for several minutes before the thing would drive without bucking and sputtering.

With SU's I've always been able to drive the car immediately after starting, regardless of the temperature, without a lot of fuss. I thought the Mikuni's were supposed to be so wonderfully advanced; the car really does get up and go with the engine fully warmed up, but it would have been nice if the Mikuni's were an improvement over the SU's in every possible way; instead I have to play games with the accelerator pump, and open the throttles just right... PITA

I'm starting to look at other things on the motor I might be able to alter to help the engine run better when cold (aside from putting the Mikuni's on ebay).

The car with Mikuni's has the asymetric five bladed fixed fan; it also has a ceramic coated exhaust manifold. I'm guessing neither of these features are helping cold weather performance. I don't want to get rid of the exhaust manifold, or the aluminum intake.

The first thing I can think of is to put an electric pusher fan with thermostat control in front of the radiator and getting rid of the fixed fan entirely.

The other thing I thought I could try is to put in a higher temperature thermostat.

Beyond that, the only thing I can think of is to try and fabricate some kind of air preheater on the intakes of the carbs, and maybe a radiator shutter of some kind.

It isn't all that cold where I'm at; low 30's to mid 40's

I'm sorry I didn't stick with the SU's, to be honest; information and support about Mikuni's for Volvo applications is simply too thin on the ground. I have no adequate frame of reference for knowing what is normal and what isn't with this carb setup.

Bill