2150 @ sea level

[Max Power]

The thing ran great in colorado from 5000-12000 feet but idles like crap here in D.C. I leaned the mix, and adjusted the idle speed, it runs great on the hiway, but at stoplights, it goes to 700, then upto 1000, then down to 600, repeat a few times, then slowly dies. but will start right back up. I cant find any vacuum leaks.

also when I take my foot off the gas @ hiway speed, it 'hitches'like the engine wants to quit for a second, then keeps going fine.

Replace? rebuild?? make it into a birdhouse???

TIA,
Robert

[joe]

The altitude compensator should adjust for the elevation change but if it's ever been messed with it prolly doesn't work anymore. It's not adjustable.
You say you've been running at high elev and then went down to sea level and leaned the carb out? You need to "enrich" the mix down at sea level.

[mandoneer]

is the 2150 series carb your talkin about a 2109? if it is you might never get it to run right and I would replace it with a newer one they have this stupid check ball in the accelerator pump and it falls out I think that "BIRDHOUSE " is a good idea if you have birds small enough to fit through the venturi's

[mandoneer]

and you need to enrich the mix when you drop elevation not lean it

[mandoneer]

sorry I didnt see JOE'S respond and he said it right

[Max Power]

thanks Joe and Mand, I guess I did enrich, I backed the screws out a bit till it was idling approximately @ 800. for a little while (then the tach starts bouncing)

Dunno if the altitude compensator has ever been messed with, if it was, it was by the PO. The TSM sez the MC 2150 is for 4000 ft and above....
and if I'm reading right, the aneroid opens the extra 'half barrel' at higher altitudes to allow more air into the mix to prevent an over rich mix. So what I'm saying is that the aneroid should be closed down here by the ocean.... Right??

[Max Power]

So what I'm thinking is why not remove the altiitude compensating circuit and open the extra 'half barrel' all the time and then set the mix?? any thoughts??

thanx,
Robert

[Don S]

Originally posted by Colonel Angus:
So what I'm thinking is why not remove the altiitude compensating circuit and open the extra 'half barrel' all the time and then set the mix?? any thoughts??

thanx,
Robert..
Colonel Angus:
... The aneroid only lets extra air into the intake as you gain altitude to take care of the progressively riched fuel ratio. The aneroids can get gummed up and stuck. I fixed mine by spraying B-12 down the throat of the compensator intake and then sraying the shaft that sticks out the back of the carburetor with the engine running. That shaft should slide in and out but don't force it.

IMHO I would just clean it..
link>HAC Carburetors and Aneroids (http://groups.msn.com/ATexasOklahomaJeepClub/ouraycotopic.msnw)

Good Luck.. :D and CUL.. Don S..

[Stuka]

leaning it out is not the right thing to do. You need too richen it up. Thre is less oxygen at 8-11k ft, so you then lean it out to get the mixture right. at sea level there is WAY more oxygen, so you need to richen it up to get it back to stoich.