Temperature on exhaust manifold

[mopetta]

I got one of these fancy IR-Temp gauges, so I checked the temperature at the exhaust manifold (bunch of bananas).

1 - 190
2/2 - 190
4 - 95 

After I checked the compression, all cylinders between 80 - 90. 

Any Idea why exhaust on cylinder 4 is only 95 degree Celsius ?

thanks