Chevy 250 cid

Hey there

I have a stock 250 cid Chevy engine. I want to set the timing, it starts a little rough and sometimes back fires through the carby..

What is the degrees advance that i need to set it at? Im 6000 ft above sea level..

Thanx for reading.  

can you narrow down the year??? and application??? there are a few variations..


if you have a 250 with a HEI distributer...  be sure to take the distributer cap off..  grab the rotor twist it lightly against the advance springs..  release... grab it again... does it snap back to the stop..    if the mechanical advance hangs up.. you will have issues..  i have a had a few hang up..

keep the ignition advanced when idling or attempting to restart the engine..

if you have points and condenser.. you will want to check the point dwell with a dwell meter..


has this been doing this for a long time..  winter blend fuel has just come out..  if you have winter fuel.. warm weather.. you might be having fuel boiling issues...

you could also need to rebuild the carb..  just a fresh set of gaskets in the carb can really help those...

please.. don't over tighten the various screws... they need to be snug ... not cranked down bending the castings..  if you run into stripped out screws... go smaller with a heli coil kit..  and smaller stronger screws..


carbs used on chevy 250 motors..

62 - 67 carter YF
63 - 67 rochester B or BV
68 - 76  rochester MV
68 - 76 Holley replacement model 1940
77 - 79  rochester 1ME  

Hi there,
Like many 6 cylinder motors 38/39* on the dwell meter
is good. What carby are you using??  
skyeking