I recently acquired a La Pavoni, 1978-82 vintage. I have pulled good shots with it, but with many shots, the second half of the pull gets thin, bubbly, and splatters as it drips out of the portafiler. It doesn't look like the videos I've watched. The crema resulting from these pulls tends to dissipate quickly. I'm using the standard portifiler that comes with the unit, but I removed the small extension that screws on the bottom (it still splatters when its on). I haven't found any variables that affect the splatter (grind, tamp pressure, pull pressure), but am starting to suspect temperature as the culprit. Am I pulling at too high a water temperature?

It seems more likely that your grind is off, or that your distribution is not good enough.
Without knowing what grinder you use, how much ground coffee is going in how much espresso (both weighed) comes out and in how much time it is difficult to say much more.

How does the result taste? Pls have a look at the Sticky of all time, 'how to adjust ....etc for guidance on adjusting parameters by taste. (Unable to access and link to it from my mobile)
Too high temperature would get you an ashy burnt taste, to fast flowing shots (whatever reason) leave you with an overly acidic result in the cup...I suspect you'll have the latter.

Marcelnl wrote:How does the result taste? Pls have a look at the Sticky of all time, 'how to adjust ....etc for guidance on adjusting parameters by taste. (Unable to access and link to it from my mobile)

Here's the link that Marcel is referring to: Espresso 101: How to Adjust Dose and Grind Setting by Taste

I have a 1978 Europiccola. Are you using the standard double filter basket? The "singles" one is tricky. If you do not have some sort of weighing device, you should get one. I normally use a discarded laboratory balance I rescued from a trash bin at the University, but you can buy amazingly good ones that weigh to the nearest 0.01 gram now for less than $10! But be careful when you buy to get one that reads in normal gram units instead of such foolishness as grains, scruples, drams, and ounces. (But, I guess a good dose would be about ten scruples.)

You might also considering buying one of the now inexpensive IR thermometers. If your machine be chrome plated, you will have to stick pieces of tape on to spots where you want to read. You can also read the temperature of emerging espresso, especially with bottomless portafilters.

Usually when La Pavonis are way too hot the liquid boils as it emerges from the portafilter and the bubbles tend to dissipate without much crema. I had serious problems with mine with low pressure, the relief valve would not seal well enough. I replaced the metal ball in the valve several times, but the only good solution was to get one of the modern polymer mushrooms, many espresso supply places have them.

You need to have some way to measure pressure to know what is going on. I believe you can buy gauges with hoses that fit over the steam tip. You can also buy an industrial type pressure gauge and put a cap on its fitting that is bored and tapped with M6x1.0 threads, and screw this on in place of the steam tip. You can also put a pressure gauge on the sight glass for permanent installation. However, I use a M32x2 threaded brass cap with a gauge that I made with a lathe and giant die. You do need to choose some way to measure pressure. (There are places in China that sell gauges with standard units instead of weird ones.)

Grinding and tamping is critical, as is proper bleeding before the first shot. HB is replete with comments on all of this.

Thank you all for you're suggestions. I'm confident the other variables mentioned are under control (grind, tamp, weight, etc). More and more, I believe my splatter issue is due to the La Pavoni running too hot. This morning I temp surfed to a lower temp (shut off the unit a minute before pulling a shot) and pulled a very nice shot. I turned the unit back on, let it heat up, and pulled a hotter shot that splattered. The first shot tasted very balanced. The second leaned more toward the sour side. I may get an IR thermometer. I've been unable to get reliable temp readings off the runnings coming out of the portafiler. Thanks again.

Other temperature measurement options that keep both hands free are attaching a food thermometer to the group or adding temperature strips. Measuring as you do the pull is very helpful. It helps to measure on the group itself, and Robert likes to measure the stream of coffee exiting the portafilter.

Adding Thermometry to a La Pavoni Europiccola

How accurate are temperature strips: time lapse video

Reaching the Zen Zone with a Two Switch La Pavoni