Categories: Features
3 years ago | Updated 3 years ago

We Can Rebuild Your RC30 Carbs Trust Me!

It’s really not as bad as it looks, I’ve watched guys do this a hundred times. Don’t panic, most of those parts are just emissions related or typical Honda over-engineering, and we don’t need them. Here, I’ll walk you through it.

  1. Screw the needle jets (or is that the jet needles?) into the bottoms of the four carb bodies (the four longish brass-colors doohickeys in the middle at 3 o’clock). Then screw the main jets into the bottom of the needle jets, but remember what number is stamped on them because we may need to go back in later 146 times to replace them with a different size.
  2. Stick the jet needles (the things that look like needles at 8 o’clock) into the slides (the round black things that look like 110V outlets at the far left) with the teeny round washers under them, slide those assemblies down into the tops of the carb bodies so that your jet needles slide freely up and down in your needle jets, and pop one of those big springs on top of each one so the throttle doesn’t stick open again like Casey Stoner’s did at Suzuka!
  3. I think those four round silver jobs at the bottom left screw into your carburetor tops (those other four black plastic roundish things at left with big holes in them), for tricky quick trackside needle adjustments, which should always be changed at the same time as the main jets! Use the four round blue gaskets down there and plenty of that orange stuff that comes in a tube.
  4. Pop those tops on top of the carbs and really tighten four screws on each one with an impact driver so they don’t blow off in case of a backfire.
  5. We’re halfway there! Onto the carb bottoms, where the float bowls reside: The white plastic fishing bobbers (floats) get attached to the carburetor bodies using the small steel rods beneath each one, which act as hinges to move the float needles (the little nylon-tipped bomb-looking things) up and down to let gasoline into the float bowls as needed. Ignore the manual, which probably says the floats need to be adjusted to some ridiculously precise height or other; that’s just the lawyers talking.
  6. Now that’s done, install the float bowls themselves, which hold the gas to be sucked up through the jets, main and pilot, which will soon be projecting luxuriously down into them, bathed in fuel as if in Soichiro’s own hydrocarbon Jacuzzi! (Don’t forget the pretty blue gaskets and more orange epoxy stuff!) The “Ventura Effect,” named for the former governor of Minnesota who sucked, will draw the gasoline up into the airstream, creating a lovely combustible mixture. Be sure to use a large torque wrench to tighten the float bowl screws to 92 foot-pounds lest the fuel leak!
  7. Finally, screw in the float bowl  drains/access plugs (at 3 o’clock), which will make it super easy to go in and change main jets 342 times if you have hands the size of Barbie’s. If you smell fuel when it’s all back together, check the bottom of your shoe for one of those round blue gaskets, then go back in with more orange epoxy.
  8. It’s all downhill from here, assembly is simply the reverse of assembly! Arrange the four carburetors such that the intake sides of the carbs (the bigger ones, probably) all fit nicely into the big pretty aluminum plenum at top left, while all four of the smaller holes line up with the engine’s four intake manifolds, which are rubber for a reason. A sledgehammer is helpful at this stage.
  9. Once that’s done, it should be simple to use all those rubber hoses to make sure gas gets to each carburetor; then just arrange all the shiny long rods and things up there (the linkage) such that all four butterflies open at exactly the same rate when you twist the throttle.
  10. As for those Ninja throwing star-looking deals at two o’clock, they reek of government interference  in matters best left to the state; throw them out or put them on the San Francisco Craigslist.
  11. Take everything apart and remove and clean the pilot, or idle jets (the long brass things projecting from  bottoms of the carb bodies), which somebody forgot to remove and are full of crud, which is why your bike won’t start.
  12. Next time: How to Synchronize your Carburetors using open-ended vacuum tubes full of highly toxic mercury!