Mike, there are a few queastions you need to address. Firts, what do your plugs
look like? Is it black and sooty? If so, then you do need to lean out the old
horse. The higher in altitude you are the smaller the jet must be. I am at
nearly 8,000 feet and I had to run a 47 or a 48 to get it to run right and not
soot the plugs. But at sea level up to about 2,000 feet, I would start dropping
jet sizes down until you get a noticable drop in power then go up 2 sizes. I
would guess you might need about a 53 or a 52. This will help on milage and
emissions. Adjust the mainjet after the jet swap to highest idle and drop it 20
rpm's. This will further help emissions without sacrificing any power.
MKlepp4335@cs.com wrote:
> The rochester carb I had on my 235 originally came off a 216. Its original
> main jet was a "51". I rebuilt another rochester from a late 50s school bus
> (maybe a 261) that has a "65" main jet. Questions: Is the 65 too rich for
> my 1/2 ton 235? What is the standard (stock) jet for the 235 engine with a
> rochester? Thanks again.
> Mike Klepp
> '48 3100
> Wichita Falls, TX
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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