Rough running new carburated rebuild
 

Need help! new rebuild based on a 2.4. I opted to have the zeinth carbs rejeted with weber jets and venturies. the specs are V 34, M 135, I 60, AC 185. running mhale 90 mm P&C, Ported Heads and matched mainfolds. MSD6A, Jacobs coil and wires, Pertronics, Solex grind on camshafts, Bursch headers and supertrap exhaust. Everything new or rebuildt . The problem is at low RPM crusing when you accelerate hard @ 2800- 3200 RPM their is missfiring and some carburator hicups. Gets progessively worse as it warms up.

Hi:

Well sir,....I see some major jetting issues,...:)

First, you MUST make certain that your fuel pressure is at 3.5 psi, your float levels are PERFECT, and you have effective fuel filtering (I use A Racor 110a). Failure to do all this renders any jetting changes useless.

With Solex cams, make sure you have 150-155 mains, and 180 AC. I cannot make an emulsion tube recommendation since I never use Zeniths, but that part is critical as hell and would help address your complaints. Webers use F3's these these applications.

You may want to check into another thread on this forum discussing tuning aides like the LM-1. Always helpful when unsure if your running lean/rich after everything else has been addressed per Steve's recommendations.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/243607-using-af-ratio-meter-our-porsches.html