Datsun Roadster Forum-311s.org

My service screw for the carbs is the useless, too short, why did they do that to me screw! Someone even put the screw in backwards to make it even more challenging. I tried wedging multiple post it notes under the screw to increase engine speed, but it didn't work well and I could not get the RPMs where I wanted them. What have others done to address this issue?

The service screw works fine on two of my 2000s but on the third, it is just hard to access, even though it is long enough. I have a small hardwood wedge that I put between the screw and the manifold. It is tapered so I can set the rpms to what ever I want and I don't need to mess with a screw driver as it's pretty loud setting the high speed balance at 3500 rpms, I just remove the wedge.

jrusso07 wrote: ↑Sun May 03, 2020 6:33 am The service screw works fine on two of my 2000s but on the third, it is just hard to access, even though it is long enough. I have a small hardwood wedge that I put between the screw and the manifold. It is tapered so I can set the rpms to what ever I want and I don't need to mess with a screw driver as it's pretty loud setting the high speed balance at 3500 rpms, I just remove the wedge.

That is what I was missing - something tapered that I could wedge in there while I had the screw driver prying the throttle open there. Thanks for the idea, now to see if I can get something similar to what you have!

On the 67.5 the service screw worked great. In 68 the introduced the thermo valve and fuel return to the tank on the rear carb to deal with vapor locking. The service screw has a bad habit of hitting the thermo valve and holding the throttle open. The balance between long enough to work and short enough to clear was pretty much a lost cause. I use a folded up business card to wedge it open. The hardwood wedge is a great idea.