Originally Posted by Danielbolt
What size jets does your 228s have for the 261 setup? I'm having trouble finding any info on jet sizing other than people talking about adjustable jets. As of now, I don't plan on having much altitude variation. I live at 1300'.

I was able to find that my Zenith 11658 has a C52-7-34 Main Jet. Some of the other Zenith 228s for 270s have C52-7-33 Main Jets. One would assume the 34 has a slightly larger orfice.

Sorry, I don't know. mine both have adjustable main jets, which is both a blessing and a curse. You'll just have to start with the stock jetting and vary it from there.

I live a 2,000 feet but regularly travel from sea level to 6.000 feet. I find that the idle mix needs adjustment if I'm at altitude. When I get to the low desert (cold, dry air) I richen up the mains a quarter turn. If I don't, a valve begins to stick open as the guides are a bit too tight. Along with that there is the danger of a burnt piston.


1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.