Blue Sapphire

Thanks for that reply. Useful info. Lots to take in. It's nice to know that the "PRI" setting can be useful after maintenance; I had quite a time getting it to start the last time the carb was emptied. Still working on the problem in my spare time. No progress yet.

Thanks @ davefrombc. I'm already in possession of the service manual, so I'll take a look to see if I've... But also note that this quad has been running pretty well over the last two years since cleaning the carb, so I'm hesitant to believe that I totally botched a line. I'm open to being wrong, though!

1997 Quadrunner LT-4WD. Symptoms: Became more and more difficult to start. Eventually wouldn't start unless pulled; showed symptoms of bad starter. While replacing starter motor, I noticed that the oil window was full. There was nothing wrong with the starter motor in the first place. History: My Father-in-law moved to Florida, so he left me with this beast. When I first started with it, it was a dumpster-bound immovable mess, locked wheel drums and all. I really poured some labor onto it, and he was tickled pink to ride it around when he came back up to visit. Here's what I did to get it running: Carburetor was cleaned and updated using a repair kit. At first, many of the mysterious vacuum lines running to the carb were either blocked off or not even attached. After hours of head-scratching, I finally found a configuration that had it running. I am still not 100% certain that these vacuum lines are routed ideally. Vacuum petcock was replaced, but I suspect the new one may have been incorrectly assembled from the factory. I do not fully understand the settings/markings on this petcock (PRI), so I can't rule it out as a problem. Until recently, the quad ran and idled well for the most part. There's one bug I wasn't able to work out, which I should also mention. The quad will stall out at high speed when in high gear, for example, while given full gas on a straight road. Since this machine is mostly just a work horse that's used at slow speeds, I didn't chase the problem, but I mention it in case it's related. At this point, I'm a bit lost. The oil has been drained, and I'm just about to go remove the carb to look for a bad float. This seems like the most probable culprit to me. If it's any other carb problem, I probably won't be able to tell or identify it, so I'd like to hear some thoughts. Please consider that I have very limited experience with machines like this. I'm not afraid to tinker, but a problem of this complexity is on the overwhelming side for me, so I'd really like some troubleshooting advice. I'll also appreciate it if you keep it simple. Just so that I'm going in the right direction, where should I be looking first? How do I troubleshoot this carb? If it's not the carburetor at all, what else could it be? Thanks in advance.