won't idle/ overheating

[smosher]

Problem is as I see it is the A4 is way too clean.

I thought that the A4 ran better the older it looked

[sunnnnseeeker]

Don,

I have been thinking about the extended needle valve. I think it would be easier to make a tool (screwdriver cap type tool about 2 inches long) that will fit over the exisitng needle valve screw. This will eliminate having to do fine machining at higher costs to get the needle valve correct.

Nathan

[Don Moyer]

Nathan,

That was our first thought as well, but unfortunately the screwdriver head
of these needle valves have had different diameters over the several decades
of their existence and we wanted a "one-size-fits-all" product. In this day
of wonderful computer driven machines it's easy to become spoiled as we snap
our fingers and see things materialize before our eyes.

Don

[gregt]

Idle adjustment...

Reading the post and replies about the idle adjustment was timely as I had a problem with loss of power when I reduced the throttle and had no idle. I adjusted the idle screw on the carb as per the instructions - I turned the screw in until it seated then out less than a quarter turn. This improved things quite a bit as I now could run at slower speeds and at idle. The engine still stalled occasionally when idling so I repeated the adjustment, but this time the idle screw is (my guess) less than 1/8 turn from seated. Is this normal, or should I look for other issues in the carb? Thanks

[Don Moyer]

We have found this condition on quite a few carburetors from the early to mid 1970's (though not necessarily restricted to those exact years), even on those which have been cleaned and in otherwise good condition. As long as the idle mixture can be made a little too rich by turning the adjustment all the way in to the seat, it would demonstrate that you have control of the mixture by then backing it out until the mixture is correct.

In short, I wouldn't necessarily go looking for any other trouble at this time.

Don

[gregt]

Thanks Don. I suspected this was the case. By the way you are correct about the vintage of the engine / carburetor. It is a 1971 A4 in a C&C 27.