I'm midway through cleaning my 1981 650G carbs (Hatachi), and was reading the tech write-up: HOW TO: Clean the Enrichment Circuit Well I was reading Chacal's post and thought I would confirm what he wrote here: "Finally, just for curiosity sake, I notice that the 1980 XJ650 Maxim carb bowls show, in the parts diagrams, a removable starter jet. I've never had one of these bowls, so I can't say for sure, but I have no reason to suspect that the factory lied about it!" Seems that the 1980/1981 650 does in fact have a removable starter jet. Can't say for other years and models, but pretty easy to check with a light. Just look for a slotted head on the jet. Here are some pics: I used a Molex connector pick (blade removal kit), very narrow, but seems a bit more rigid than a regular screwdriver. It took a minimal amount of pressure to free the jet. And then about 6 turns to get it loose. Once out, cleaning the passage is really easy. However, the jet is another story. It has a tiny tiny passage and the micro-drill bit is pretty much a necessity (in a pinch you can use a very fine sewing needle). My jets were clogged solid and took quite a bit to open them back up. It should be noted that I boiled my float bowls for about an hour in 50/50 water/vinegar. Although these screws probably would have come out without boiling (just makes it a tad easier, plus cleans your bowls). At the same time I cleaned up the bowl drain passages and freed the screws. If they are stuck in, I usually just use a right-angled impact to rattle them out. I've tried other ways but the right-angled impact does this in seconds without stripping the screw head. Note: it's a two person job, one to hold the bowl and the other to hold the rattler firm. Very easy and no messed up screw heads... or better yet driving the screwdriver into the palm of your hand. Picture for reference (from Popular Mechanics): That's it... looking forward to easy starting!