Originally Posted by
Truckracer
I learned a lot from Clarence's articles years ago but these days, I seem to differ with some of his opinions when it comes to gas engines. Case in point, he has repeatedly suggested removing the screen in Walbro carburetors which I highly disagree with. He suggests it gets plugged too easily and I suggest if it is getting plugged, the fuel going to the carb is contaminated which will ruin a carb in short order if that "last line of defense" screen is omitted. I have written letters but no response. He continues to make that suggestion from time to time and my fur gets ruffled whenever I read the suggestion. I check my screens once a year and in most cases find nothing in them. I couldn't imagine removing them.
If I remember correctly from my old Quadra days the reason for removing the screen was to allow any tiny amounts of water (read condensation) that would form to be sucked through the opening instead of collecting on the screen and inhibiting the engine from running. One thing Mr. Lee was a fanatic about was filtering your fuel into the model thus the lack of need for a filter and screen in the carb. Today there are enough additives (the alcohol in fuel helps absorb water) the fuel stability being better and we tend to use smaller containers and go through the fuel faster I don’t see any water droplets forming on that screen very often any more. About the only time is early in the year after the fuel container has sat near empty over the winter. The fellow is either trying to use it up or just added to what was there.
I agree with you I have not felt the need to remove that screen in many years. Like you the two things in those carbs that can give trouble are the pump diaphragms and the screens. They both come in the kits and are relatively inexpensive. I have the cowl off before first flight in the new season to check everything over it takes but a few minutes to replace both. Cheap insurance. In each engine manual I have the carb kit number written down. I make a habit of having one on hand and when that plane leaves the hanger the carb kit goes with it. It’s saved the weekend on more than one occasion and even helped a good friend out once.
Someone once said you cannot have too many toys. My experience with mechanical toys also tells me you cannot have too many spare parts. LOL
Dennis