Has anyone tuned one of these carbs, since Jay did his?
All the time.
If I recall correctly (it's been about 40 years LOL), there were no replaceable squirters like a Holley has, or if there were, different ones weren't available. My accelerator pumps would each spit out 1-2 little drops of fuel from each pump. Certainly nothing like a stream of fuel that you get from a Holley pump. I replaced the pump diaphrams and the check valves to try to solve this problem; I remember buying some Autolite carb rebuild kits to get all the parts I needed. But this didn't solve the problem. It just seemed like the accelerator pump chamber wasn't filling with fuel.
Bear in mind that these carbs were far from new when I got them, and may have been modified from their stock condition. Who knows what issues they may have had...
Well clearly, the pumps were inactive and no surprise it stumbled with no pump function. I certainly can't say what was available to you 40 years ago but 50 years ago tuning parts were certainly available (and are from me now) and the shooters are indeed tunable and replaceable. Replacing them is not as easy as it should be but they almost always need to be larger (unless previously modified), and you can do that with a wire gauge drill and pin vise without removing them. Replacing them is a little more involved as seen here on my website.
https://inlinecarb.com/uploads/3/4/4/8/34481757/replacing_shooters.pdfThere were also mod kits for the check valves. They could be helpful but weren't necessary most of the time though I do recommend this and a mod of my own for IR carbs.
https://inlinecarb.com/uploads/3/4/4/8/34481757/conical_check_valve_modification_for_accelerator_pump_circuit.pdfThere is a .014" bleed vent to the pump well from the main well and if that becomes plugged by old fuel (which almost is always the case with a carb that was put away wet), the accelerator well often will either not fill or not fill completely. As a matter of course, I make sure they are clear when I rebuild a carb. Also, there are a number of things I do to insure the check valves function properly.
The most common thing I get is from folks is "my carb is NOS" so I don't need rebuild parts. -Not true. 55-year-old accel pump diaphragms are so hard they won't move regardless of whether they have ever seen fuel......which means they won't pump.
Finer tuning with the emulsion tubes is similar to Weber carbs in principle and neither hard to understand nor to do. You just have to be willing to do it. A good tach and A/F meter helps a bunch......but this is so tuning any carb.
As Barry said, IR systems can be a bit finicky, and by nature want a completely different jetting and enrichment scheme, and truth be told, different cam profile and ignition curve. But I've had owners that throw a stock carb on a unique IR engine combo, and when it won't run worth a pooh, or at all, they throw their hands up and blame the carb.
I have customers that are just collectors and that's fine, but I enjoy working with those that intend to run them and that's why I make custom systems (and because I like the challenge of making them). If you have tuning experience, and understand the basic functions of carbs, an Inline isn't hard to understand and although I can't virtually tune everyone's unique engine combination via email, I can usually talk a reasonably versed person through it in a phone call.
This is just hobby stuff for me so whether you want to run an Inline doesn't matter to me, but for those who do want to run them, I try to accommodate and support them, and the reasons people do are probably not much different than the reasons they own a 60-year-old car or build on a 50-60-year-old engine platform.
The discussion here in this thread is fairly typical, I'll quit bangin' on about it cuz it's not really FE talk, but Inlines are tunable carbs.....it's just unrealistic to expect them to suit every unique engine in the configuration they were originally built without tuning.
Best,
Kelly
