Things were going so well with the carb refurb and then I made a series of really silly and compounding mistakes. One carb is fully assembled and when working on the second, without realising it, I put the spindle in 180 degrees out from how it should have been installed. Then when attaching the fuel pump actuating cam, which requires knocking a split pin through the cam and spindle, this jammed.
Rather that take a breath, reflect and make a sensible decision, I departed on an a course of action which has turned out costly. The split pin jammed with about 3mm protruding (I’m not surprised now as I don’t think it would have every gone through with the orientation of the spindle incorrect). This was fouling on the inspection cover plate and prevented reassemble the carb. At this point, I didn’t think the issue with the orientation of the spindle was any big deal as I couldn’t visualise how it was causing the carb to not function properly. So, rather than be sensible, I ground off the excess split pin so it was flush with the collar of the actuating cam allowing me to close the inspection plate and finish the reassemble.
Turns out this was a silly thing to do. With the spindle 180 degree out, the arm of the actuating cam was not lifting the fuel pump high enough for it to work properly. I noticed the difference in the height of the fuel pump when I had the two reassembled carbs side-by-side. The job of this pump is to literally spray fuel each time the accelerator pedal is pressed, this helps the engine get going and create the Venturi effect to draw in the rest of the fuel. Without the pump working fully there would be less fuel reaching the engine on initial acceleration and I suspect that this would serious impact performance.
The spindle had to come out again but this can’t happen without the actuating cam coming off and this was firmly attached by a jammed split pin! The solution was always going to be destructive! I tried drilling out the split pin using a cobalt drill bit but that metal was about as tough as any I’ve come across. When this failed, I then tried to cut away at the collar and leave the spindle in tact. This is how well this approach worked:
I’m afraid it didn’t at all! I ended up having to cut all the way through the collar and spindle. Pay day tomorrow and almost £100 of car parts with VAT and delivery (and I suspect an import charge too). Stupid mistake to make, but at least I haven’t done anything to the carb itself. There was always a chance I would slip when cutting… very relieved that didn’t happen!
I suspect it will be a few weeks before the parts arrive. Hopefully I can get everything back together and on the car with a basic tune. I’ve identified a local(ish) garage that can tune Webers using a rolling road. Would be good to get a horsepower number as well. Something to look forward to as this episode hasn’t been my finest!