In Reply to: Jets size posted by Pete Landon on June 24, 2020 at 20:06:22:
First, I highly advise NOT to try drilling out any carb passages especially with a hand held drill unit. If you break off the drill you will most likely not be able to burn it out. Are you having major carb issues or just doing some standard PM work? Granted it’s your tractor and you can do anything you wish on it, but this one of those things I’ve learned from experience. Having rebuilt several M/S TSX carbs and used the different models on my Fords (TSX 33, TSX 241) it only took me one time breaking a tap to seek a different approach. I remove carb from tractor, disassemble the two halves and remove gaskets, needle, and float. Place parts in a coffee can, fill with lacquer thinner, cover, and let set for a week or more – the longer the better. Carb cleaner use to work great but nowadays may or may not work. OSHA demands non-toxic substances to be used now. Remove parts and blow off with compressed air. Begin removing brass adjusting screws and all other screw-in parts. Set halves in sandblaster and clean inside and out. Place back in a coffee can with fresh lacquer thinner, mineral spirits, or 50/50 acetone mix, cover, and let stand for a week longer. Remove, blow dry, and begin inspecting ports. I use old guitar strings and pipe cleaners to chase passages, never any drill or reamer. The thinner will help dissolve old gummed up gas and I’ve had some units that if left setting for ten years or more can get plugged up with dirt. I use a telescoping inspection mirror and magnifying gas to inspect passages well. Cleansing with thinner, air blasts, and old guitar strings chased with pipe cleaners are all I use. Beginning in 1947 Marvel-Schebler began attaching a brass ID Tag with a rivet on the cast ‘ping-pong paddle’ of the carb body. It had the M/S carb ID number (ie TSX 241B), and the date code stamp when the unit was produced. FWIW & FYI: A 1,25 mm (metric) size is .0492” (inch) which is no doubt what the company used if indeed that passage was listed at .050" -they would NOT have made a special drill size just for that. A 3/64 drill ( .0469") would be standard and if used, would have been rounded off. Any tooling supply company sells drill size charts and drills. A #55 drill size = .052". Guitar strings come in Light, Medium, and Heavy gauge sets –see chart. I use 10/MED's on my Les Paul, heavy's on my acoustic. I have many old used strings if you want some. Pipe cleaners are sold at local tobacco shops. Also, there are a few OEM Marvel-Schebler documents in our HOW-TO’s to download for reference. I have a few OEM M/S carbs I’m rebuilding now. If you want, send me your unit and I can clean and rebuild or core exchange with your original as long as it hasn’t been drilled out.
GUITAR STRING GAUGE CHART: