lean best idle for weber 38

[davida]

I just bought a brand new weber 38 from pierce and I am having trouble setting it up. I tried to follow the procedure on the pierce website, turn the speed screw in 1 full turn after contact, and the idle screws out 2 turns, but I can't get the car to remain running long enough to make any adjustments. I have a reground cam of unknown specs and pierce gave my 50 idle jets. Any recommendations?

[Slavs]

I fiddled around with one of those carbs.

When I got the car it was running horribly with flat spots all over the range.

The 130 mains are way too small. I went up to 142s and cured the stumbling. The 60 idles were way too sloppy. I couldn't get a precise enough idle with them. The 50s on the other hand were too small. 55 idles were out the best.

I eventually replaced the 38/38 with a 32/36 because the 32/36 has superior drivability characteristics. The 38/38 has too little range for my taste. It is an all or nothing caruretor You either got little power or you got just about all of it with very little range in between.

The 38/38 will also get you 16-18 mpg. The stock 2002 with stock carb gets about 21mpg (city). The stock 1600 gets 22mpg(city).

Slavs

[JohnW]

Two turns out on each idle screw is way too much. At least it was for me. I have each screw one full turn out. Works great. I get between 20-23 mpg every tank. Runs great. A nice increase in performance and drivability compared to the 32/36 it replaced.

Also, FWIW, I'm using the same jets it came with when I purchased it from Maximillians 5-plus years ago. But I also have 9.5:1 pistons and some other minor changes from stock.

[davida]

I tried 1 turn on the mixture screw, still a no go. I have 140 mains, 180 air, and 50 idle. any other suggestions? Is it possible that I need bigger idles, or am I just not adjusting what I have properly?

[Timmer]

The 1974 2002 I had prior to my current 1969 2000, a few years ago, had a rebuilt engine with higher compression (9.5:1 and a Schrick 292 cam ). I went from a 32/36 that was on the 2002 when I bought it, to a new 38/38 and put in 55 idle jets, didn't fiddle with the air. corr.'s or mains but the 55's gave the car a pretty good idle, got the mixture screws down to 1.5 turns out each, with the standard size 42 mains, the mixture screws were about 4 turns out each. Even with the 55's, the idle was still a bit "lopey", due to the 292 cam. Try 55's and see how they work for you.

Tim

'69 2000

[davida]

I'll give the 55's a try and see how they work, thanks.

[acmeradio]

Just for reference...I had TEP jet mine...it ran great from the day I bolted it on. I think I'm a 1.5 turns out. No more than 2. I've got Hi-comp pistons/Shrick 292/IE header/and other evil under the hood. I know when I researched past posts...most people suggested running 55's.

150 Mains

180 Airs

55 Idles