VFR750

Right now I am running 60/135-162/165. I have been working on a lot of things, and have not gotten around to post them. Now that summer is over, I'll probably post more of the past years work. I would have stayed at 60/145-162/165, except that I tried a modification to the transiton ports that backfired (literally!) To offset it, I had to drop the Idle Air Correction jet from 145 down to 135. That launched a huge effort to figure out the transition port effects. That effort has occupied the whole summer.

Since you went to 36mm bore, you will likely see a bigger flat spot becuase the mains will take a little longer to start. I would recommend setting the float level at the high end of the guage, with the menicus (bottom of the liquid in the gauge) at the upper line. This way, the mains will start the earliest possible.

Plus, you're going to need more fuel as you flow more at the top end. So either go with a #165 main jet as a starting point.

I too am trying to put the right jets into my zenith 40 tin carbs installed on my 3.0L 911. I just had the venturies opened up to 36mm from the 34mm I started with. Your forum was the first bit of light that I've been able to find. I stumbled across it when you were testing for a flat spot in your accelaration. You were running 60/140-165/165 and were messing with a 60/145-165/165 combo and I lost you. I was wondering what combonation you ended up running as it would help me start out that much closer to where I need to be.

Have you ever considered using a plenum or balance pipe in the intake to make the Zeniths look bigger to the engine? I am building a 2.4 l and the cam grinder tells me I need 46mm PMO's. I was thinking a plenum would be cheaper.

Any progress with the emulsion tubes?

Thanks,
neil

Yes, still available, Sunday June 6th

Sir,
Still have 1-1/4 in spacers?

Fred