Engine only stays running if throttle is pumped.

[fussfeld]

Engine starts easy but will stall after about 2-3 seconds.    However, i can keep it running if i keep pumping the throttle.  It won't run smoothly of course, but it will still stay running.

Completely stock 4.3 v-6
The quad is originally off of a 305.  i rebuilt it in Jan 09 and it ran ok on a 350.  It has been sitting on the shelf since Jan 09 until about 3 weeks ago.    i have been hearing suggestions about plugged idle passages/jets, but i don't see how a carb could get plugged just sitting on the shelf?

[StillLearning]

Your symptoms are classic for a clog somewhere. Your accelerator pump works but the main system apparently does not pick up.  If the carb had some fuel in it, even just a little in the bottom passages, it evaporated and left varnish deposits. I had a small insect get into a stored carb once. Your best bet is to disassemble it and soak it to clear passages. Blow them out with air. If you haven't already done it, install a kit from Cliff's. You then have a carburetor which will work with alcohol containing gasoline. Hope this helps you....

[Frank400]

I've had the same problems a few years ago with a carb that had been sitting for only one year.  Idle tubes were clogged with white "powder like" stuff.  Cleaned them and all was good after that. 

  If you don't wish to remove the idle tubes, you can always us some .023" mig wire and clean them while they're still in the carb.  Not as good as removing them but...

[Cliff Ruggles]

For sure it needs to come apart for cleaning and put much better parts in it.  We've upgraded everything in our kits in recent years for this new fuel, nothing in 2009 will hold up well to ethanol, especially the pump seal.....Cliff

[fussfeld]

For sure it needs to come apart for cleaning and put much better parts in it.  We've upgraded everything in our kits in recent years for this new fuel, nothing in 2009 will hold up well to ethanol, especially the pump seal.....Cliff

It's good to know there are upgraded parts for the new fuel;  Will schedule a rebuild asap.

i was able to solve the problem by putting the "junk" reman carburetor that originally came with the engine back on.  (i was originally motivated to replace it because 1) it's a generic reman and 2) it has the heat stove choke and this manifold doesn't even has provisions for that----i think chevy did away with that and went to all electric chokes by 85?.   So, i felt the carb was "wrong" for the application right off the bat.....)

But there's another problem;  Please see my other post.