Datsun Roadster Forum-311s.org

I made a linkage setup for webers. They fit dead on and include the correct throttle stop so the butterfly valve does not pass 90 degrees. I am including some drawings so you can see what I designed. The tab is adjustable so it can be cut to length and yes it is a center pull linkage. and yes I do have some of these on hand as I made a whole run of them The 510 guys have been using them for their weber setups and they will work on roadsters.

The linkage was a personal design of mine. I analyzed what was needed in order to make it work and then created a linkage by prototyping and also by the use of a CMM machine that I own to measure and create a working item for the Webers

The linkage that would be cool is a center pull R16 Mikuni linkage, for the easily available manifold designed for Webers. I've spent hours on a members car trying to get the dual side pull mess to work. There is just too much flex and slop in it. A cable stand and center pull linkage like the U20s use would be epic.

Will

gmagana wrote:The linkage was a personal design of mine. I analyzed what was needed in order to make it work and then created a linkage by prototyping and also by the use of a CMM machine that I own to measure and create a working item for the Webers

I have been trying to buy this set with no luck. PMs only answered with price but no other info....

Can any one help here?

Thanks

I have 40 Mikunis in the garage. What model Webers do you have? Maybe we could swap.

I'm positive I have seen that design of likeage before in my old 510 days in the 80's. Might this be a reverse engineered copy of an old existing design? Or a minor modification? As the return spring stand and cable stand are Mikuni designs for Toyota 2TG set up if I'm not mistaken. But the linkage itself is an old TWM (the weber man ) or Redline set up.

I'm glad to see this post. I have a set of webers with a roadster (me thinks) manifold but I have no intention of ever putting them on my 1600. I posted pix of them at http://goodvision.com/W/" onclick="window.open(this.href);return false; in case they add anything to this discussion. I'm curious what I've got and what they can be used on.

Those be downdraft Webers with adapters!

Thanks Shifty. I did a little searching and found a couple of vendors offering some kits. Not sure if these are the same as 'adapters' or not. I still need to figure out which model numbers I have.

http://www.webercarbsdirect.com/Nissan_ ... s_s/37.htm" onclick="window.open(this.href);return false;
http://www.alamomotorsports.com/weber/nissan_carb.html" onclick="window.open(this.href);return false;

Very high likelihood that they are Weber 32/36 DGV. Commonly used on 240Z's (mostly 73's to replace the flat top Hitachi Boat Anchor SU's.) The Z set up uses the same adapters to the SU manifold. I have seen them used on Triumph's too. A good operational set with the adapters are maybe worth $300. They don't tend to be really well liked. Most guys end up with 72 SU carbs, or triple Weber DCOE's or Mikunis...

I have seen folks trying to sell the downdraft duals for $100 for it all. They can be tough to give away...

If someone out there is running twin webber 40 dcoe's on a 1600 stroker that idles smooth, I will give you my first born for your jet numberts,
Thankws,
Blaise

rbsails wrote: Tue Apr 22, 2025 10:08 am If someone out there is running twin webber 40 dcoe's on a 1600 stroker that idles smooth, I will give you my first born for your jet numberts,
Thankws,
Blaise

Welcome Blaise, there are several folks here who can help sort out your Webers but we'll need more info to get a complete picture of what you have. For the moment however, the two most important elements to a smooth idle are balanced airflow carb to carb and properly adjusted (and undamaged) idle screws. You pretty much HAVE TO use an airflow tool like a unisyn or our preferred "snail" flow tester to make sure both carbs (as well as each throat) flow the same air... guessing won't be satisfactory. Then we need to be sure your idle screws are in good condition as they are delicate and can become damaged... i.e. the taper is not uniform or the seat they fit into becomes out of shape. Your low speed and high speed jets will have virtually no impact on idle. Other factors can be float levels and fuel pressure, as well as making sure your valves are all adjusted and your spark plugs and ignition timing etc are good. It would be helpful to examine your plugs so we can see how it's burning now.

I have not messed with Webers specifically, but have years of experience with Mikuni, their hybrids, and Dellortos, now EFI. I'm a BIG fan of wideband O2 sensor set ups but can also help guide you on how to test your jetting the old fashioned way... lord knows I spent a lot of time doing that over the years! There may be some folks who can give you more specifics on jets and emulsion tubes that will get you very close if not perfect, but not me. There is good info on the internet about how these types of carbs work and that can help a lot when troubleshooting.

So post which Weber DCOE you have (new, used, anything "special" about them), the main venturi or "choke" size in the bore (# stamped on it, usually on the leading edge, visible by looking down the bore, likely 32-36), current jets and (maybe) emulsion tube #, fuel pump being used (stock mech vs electric) and any other running issues (bogs down, won't hit red-line etc). Tell us your level of knowledge and experience in general so we can tailor our responses appropriately and we'll be well on our way to getting her right so you can enjoy the car more fully... that's why we're here!

Blaise,
I recommend you get assistance from Gron Perry, he is one of the best Weber tuners I know of.
Dave