Tony's Weblog

Today I thought I would tune up the Holley 390 on my V8.........

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Pretty simple I thought, and one of the important settings is the fuel level in the carb which you check by removing a screw on the side of the carb body. The fuel is supposed to be just visible at the bottom of the screw hole. With the engine running to adjust the level you simply undo a lock screw on the top of the carb body & adjust a nut to raise or lower the level. Easy!

So, get everything ready, undo the lock screws, get the correct ring spanner in place, start engine & get screwdriver to take out the level screws from the side of the carb. In the few seconds this takes I hear a nasty hissing noise - it only takes one glance to see fuel gushing out of the top of the carb, pouring down the inlet minifold & evaporating off the exhaust mainfolds with a sizzle to rival sausages on the barbie!

The ignition was off a second later. I keep a fire extinguisher in my garage so I stood, extinguisher at the ready, waiting for the fuel to evaporate - fortunately the car was outside the garage. The emergency passed & I wiped away any remaining fuel I could find, did up all the screws on the carb, & went back to my instructions.

Well, nowhere did it warn about the consequences of leaving the adjusters loose on top of the carb, so I set about the task again, but start the car first, take out the level screw, then undo each lock screw just a tiny bit with the ring spanner in place to adjust a little at a time. This was managed without any further dramas - the levels were too high in both primary & secondary chambers so it was worthwhile.

So, anyone out there with a Holley thinking of checking settings - beware!