Dino Saga 050918

Dino Saga 050918

Carburetor problems have been frequent in number but singular in cause and effect: The engine starts popping at constant or trailing throttle. I pull the idle jets and remove the small piece of plant debris that is clogging one of the jets. The problem is fixed. Until the next time!

The car is parked outside most of the time and we have California Live Oaks all over the property. The Oaks flower in April/May and shed all the rest of the year. Particles are light, small, long and tapered. If there is any way that anything can get by the filter, it will get stuck in an idle jet. I found a solution to the problem and found an alternative source of filter elements.

When I got the car, it had a FISPA filter element consisting of wire screening covered with flocking. It kept out bugs, large rocks and small birds but not much else. I looked at standard auto paper filters and found nothing that fit the Dino filter housing. Finally took a look at filter elements for trucks and found a few that MIGHT be modifiable. Picked one that had a 4” bore, right OD but was too long. Aircraft snips took care of inner and outer mesh and a razor blade did the paper. Silicone caulking was applied liberally to the cut end. Set silicone end on a piece of ¼” foam, on a flat table, until silicone cured. Had a custom filter! I blow it off occasionally. Make a new one every couple of years. I know; K&N has a filter you can order but it needs frequent cleaning and oiling. Got enough oil. Still have the FISPA filter.

Paper filter worked fine for a while but seal at front end was not perfect. Had to clean jets again. Suddenly had a bright idea! The problem was particles getting into the idle jets from the incoming air. Why not double filter the jets and not worry so much about all of the air the engine was breathing. Bingo!

Went to my lawnmower shop and bought Briggs and Stratton intake filter foam in the biggest piece for the least amount of money. Had enough to make three filters, every three years for a decade. I used common scissors to cut triangles that fit snugly in the jet air intakes on the Webers. Hardly any air bleeds into the jets but that little is key. The foam is completely transparent and I have not cleaned an idle jet in 10 years.

I still use the paper filters. They last a couple of years (10,000 miles) with periodic cleaning. No bigie.

The first picture shows the foam in the 3-6 Weber. The second picture shows a small mod I made for the idle adjustment. I drive the car 3-4 times a day and am lazy but particular.

It turns out that different grades of gas, slow changes in timing, changes in temperature and the phases of the moon affect the idle speed. I got tired of messing with 3 idle stops, lost motion in linkage and the innate perversity of inanimate objects. Sheared, bent, drilled and tapped a piece of 1/8” aluminum and added it to the throttle spring support. An 8-32 screw and a coil spring make a single idle stop. The springs on each carb take out the slack. I can adjust the idle with my fingers, easily, any time anything changes. And the carbs stay synched!

Small things help.

John
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