engine not idling

I have just started getting into my '81 SN after pulling out the interior.

After fitting a flush kit I thought I'd give it a bit of a start as it hadn't been started for a while.

The problem is the engine just won't idle, it runs fine @1600 rpm's + but if I cut the throttle it just dies unless the idle screw keeps it at around 1200-1500.

Now the hand throttle had been loosened and throttle cable messed with. So it's quite likley that I have pulled, bumped something.

Where to start? could I have bumped/messed with the choke somehow?

I'm reading the PCM owners manual now but I figure someone will have had a similar problem before.

Thanks

Mark

No, other than the cable being shifted and AFAIK the carbs not been done.

I'll have another very close look to see if anything is looking weird though.. going to be 38 degrees C today so it may have to wait.

All the manuals are found on this site in the reference section :-)

Bob's2001 wrote: You may need to clean and rebuild the carb. If it has been sitting for an extended period the idle circuit may be plugged. The old gas will harden and turn to varnish and the little passages in the idle circuit won't flow. When you bump the idle up you are off the internal idle cicuit. Carb rebuild kits can be had reasonably and the rebuild is not difficult, just take notes and get it all clean. And be sure you get a marine kit.

And if you do get a rebuild kit, get a new metering block too. There are a lot of little passages in there that can get clogged really easy.

And I thought you might have an 81 manual. The reference section seems to be missing it.

How long has it been since you rebuilt?

Its either a 4150, or 4160. The 60 has a different secondary metering block than the primary... On the 50, they are about the same.

Do you have the Ford or Chevy?

79nautique wrote: before you get to crazy re-building the carb make sure that it's not a cable adjustment issue first. Disconnect the cable at the carb and then set the idle mixture screws and base idle and see if you have the same issue, if so then rebuild the carb. Also before you do this make sure the timing and dwell (if a point dist) is set correctly then adjust mixture screws and idle. Also you may have a huge vaccum leak as well so make sure the carb is tight all around. Check the mounting bolts and the bolts holding the fuel bowls on as well.

Definately make sure none of that is the problem first. Good call.

The end of the cable is a spring loaded connector and it detaches easy, just pop it off and then mess with the carb. If the idle drops right off the bat then odds are the cable needs re-adjusted at the carb and the idle mixture screws need fine tuned. But a carb overhaul never hurts especially if you don't know how long it's been since the last one.