Atomic-4 dies at idle

[dchunt]

The A4 would NOT keep running while using the choke when it conked out that time.

I changed the spark plugs at the beginning of the year but did not check them after this happened. I guess I should.

When I went back to the boat the other day and tested the engine, it started right up with the choke on and then when it warmed up after a couple seconds I could shut the choke off and idle the engine just fine. I looked closely at the carb and noticed that there appeared to be a sheen of gas on the outside of the carb (late model) under the bowl where the main drain plug is. I could not tell exactly where the gas was coming from. I have ordered a bunch of carb parts and gaskets from Moyer and will take it apart over the weekend and check it out.

Dan

[hellosailor]

An engine that suddenly dies usually isn't a spark plug problem, those go bad gradually over a long time.

Usually it means that fuel or spark got cut off. The original A4 design had the ignition coil located where it would eventually overheat, short out, and cut off your spark--a common enough problem for engines with ignition coils.

But fuel on the outside of the carb is fairly damning, and of course a major fire threat.

Carbs are really meant to be stripped down and overhauled about every five years, to whether that's your problem or not, it is time to be done. If Moyer has a "major overhaul kit" with a full set of gaskets, needle valve, float, etc., that's the best thing to use.

The two problems are that gasoline naturally breaks down and forms varnish, it is intended for use within 90 days, and the varnish builds up inside carb passages and clogs them. The only real way to get 100% performance back is by cleaning them out, i.e. soaking overnight in Gumout and using a needle or wire brush as appropriate to scrub out the varnish. You'd be very lucky if you could just dissolve/blow it out, as opposed to just pushing the clog around.

If you have a digicam, cell cam, that's a great way to make sure things go back together in the correct sequence. Or at least, a big old towel to lay the parts on, in the correct sequence to reassemble them in.

If you don't go through enough gas to keep it fresh all year--add Sta-Bil or another "stabilant" to every fill. It prevents most of the varnish from forming. And if you can, empty the tank and run the engine till it runs out of gas, so there's nothing left in the carb, before winter layup. Or, at least add a healthy dose of Sta-Bil before layup, and run the engine until that's mixed and gotten into the carb.

[imagine2frolic]

You might want to take it apart slowly over a large box to keep from losing parts. I think the last time I purchased a kit was over 3 years, and over $100 if memory serves me correctly.As far as ignition parts I use to get them from an autoparts store for 1/4 the cost. Same as a forklift motor......i2f