Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Weber 38/38 DGAV


tcrock

Recommended Posts

Is there a jet/tubes set up that works best on a stock

8.3:1 M10

The motor is fresh and runs great with a 32/36.

But with the 38 it runs crazy in the upper rpm's

and has a flat spot around 3200-3500.It idles fine at

900 gets out of the hole fine and after 3200 goes like hell.

Right now there are 145 and 185 jets in it I'm not sure about

the emulsion tubes.The idle screws are out @1 turn.

Thanks for any help

Link to comment
Share on other sites

My guess is you are lean at some point in the operation of the carb.

In my limited self taught experience based on twin 38/38 on a CS is that the idle circuit effects 0-2500rpm, mains 2500 - 4500rpm and air jets to redline. The range of effects overlaps the jets but in general its a starting point on where to makes changes. Change on thing at a time. A fuel air ratio meter is also very helpful.

Generally the 38/38 stumble occurs at the transition from idle circuit to mains at around 2500rpm. That symptom can mean that your idles are to small and you have a lean condition that cause you to rely on the mixture screw to minimize. Mixture screw less 1 turn, idle screw less then 3/4 and engine idle speed should be fine at 750rpm.

Your problem sounds different given the flat spot is around 3200rpm but you have great performance above 5000 which is typically where the 38 drops off. Guessing this is where you are lean. Try increasing the main jet by one half size. If it improves but still exists go up another half size. etc etc

If this is working and you are pretty happy with the results then increase the air jet one size and see if there is an improvement. If it gets better then increase another size. Etc etc etc

76 Sahara 2002

73 CS Polaris

84 Tucker Snocat!!!

Link to comment
Share on other sites

searchy searchy searchy...

your 'transition' jets are lean. We're not 100% sure, but bigger than 50

seems to be a general consensus...

and you have to searchy to find out what I mean by transition jets...

t

"I learn best through painful, expensive experience, so I feel like I've gotten my money's worth." MattL

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • BMW Neue Klasse - a birth of a Sports Sedan

    BMW Neue Klasse - a birth of a Sports Sedan

    Unveiling of the Neue Klasse Unveiled in 1961, BMW 1500 sedan was a revolutionary concept at the outset of the '60s. No tail fins or chrome fountains. Instead, what you got was understated and elegant, in a modern sense, exciting to drive as nearly any sports car, and yet still comfortable for four.   The elegant little sedan was an instant sensation. In the 1500, BMW not only found the long-term solution to its dire business straits but, more importantly, created an entirely new
    History of the BMW 2002 and the 02 Series

    History of the BMW 2002 and the 02 Series

    In 1966, BMW was practically unknown in the US unless you were a touring motorcycle enthusiast or had seen an Isetta given away on a quiz show.  BMW’s sales in the US that year were just 1253 cars.  Then BMW 1600-2 came to America’s shores, tripling US sales to 4564 the following year, boosted by favorable articles in the Buff Books. Car and Driver called it “the best $2500 sedan anywhere.”  Road & Track’s road test was equally enthusiastic.  Then, BMW took a cue from American manufacturers,
    The BMW 2002 Production Run

    The BMW 2002 Production Run

    BMW 02 series are like the original Volkswagen Beetles in one way (besides both being German classic cars)—throughout their long production, they all essentially look alike—at least to the uninitiated:  small, boxy, rear-wheel drive, two-door sedan.  Aficionados know better.   Not only were there three other body styles—none, unfortunately, exported to the US—but there were some significant visual and mechanical changes over their eleven-year production run.   I’ve extracted t
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...