[Spridgets] Cooling Puzzle

[Robert Weeks]

Hey all,

When I got my current '70 Midget back in the spring I had a lot of 
overheating problems. Since then I've replaced the radiator with a new 
(non-Chinese) one and replaced the water pump, flushed the cooling 
system and added an oil cooler. I also retarded the timing somewhat and 
that seemed to help the most. I didn't use a timing light to set the 
timing I just did some trial and error fiddling with it to get it to 
where it would start good and run well. After doing all of that the 
water temp gauge never went above 7:00 (the cool side of normal). Until 
today............

A couple of weekends ago our local MC Club had a tech session at the 
local LBC place on diagnosing engine health and my Midget was one of the 
two demo cars. We checked oil pressure, vacume readings, did a 
compression test and a leak down test. The Midget passed with flying 
colors except that the vacume readings indicated that the timing was 
retarded and a look at the plugs showed that it was running rich.

So today I get out the timing light and set the timing and I adjusted 
the carbs. When I got done it was purring at idle. Then I looked at the 
water temperature gauge before turning off the ignition and the needle 
was pegged at the hot end of the gauge. I didn't advance the timing 
*that* much. I maybe rotated the dizzy body 3/32" - 1/8" (no click 
adjuster on this dizzy).

Is this just a coincidence that it overheated when I advanced the 
ignition sightly? Or could there be some underlying problem that I'm 
missing that is causing it to overheat when the timing is set to spec ?

Thanks,

Robert