I’m working on a friends 2006 SM950 and I’m stumped. Last fall he said he was riding it like normal and halfway through the ride it wouldn’t rev out. It started cutting out halfway through the rev range no matter how much throttle he gave it. I started with the simple things like new battery, dumped the fuel and ran fresh fuel through it thinking it might be bad gas. No dice. Next came a new fuel pump since he’s on the original and the points looked like shit. Same problem. Then I put in new plugs and tested the coils, both within spec. Same same. I’ve opened the air box back up to see if there was anything obvious going on with the carbs, but everything looks clean and tight. It starts fine and idles ok for a few minutes, then it’ll starting dropping revs and picking them back up sporadically until it eventually just stalls. I used a laser thermometer on both headers and judging by the temps, the front cylinder looks like it isn’t firing when it has this shit going on. I plan on extending the fuel hoses from the tank and running it with the air box open so I can see if the carbs are both getting fuel properly or if it’s an electrical problem. Does anyone have first hand experience with this? I’ve resurrected a number of bikes in my time, but this ones has me ready to throw in the towel! Thanks all!
I have an 06 950Adv and you have tried everything I would have suggested...so I would toss the question out over here..or look in the HOW thread. https://advrider.com/f/forums/dakar-champion-950-990.34/
You've check most of the good stuff but a few pointers and considerations: fuel pump- or more importantly the points, you can actually solder in new points as that's the part that fails, usually the pumps themselves are good for 75k miles at least. could have been an issue. Normally it will backfire if the points are going out, won't rev and then just stop. Might be able to restart and ride a few more times but you are on borrowed time at that point. For future reference the best setup is the Dr. Beans optical points from the guy on ADV Rider. Carb slides- these things are getting older. If you can run it with the airbox off, check the slides are moving the same. Some of the slides are getting cracks or tears and no vacuum to work properly. If it's just the front cylinder, that does narrow it down. Sometimes the fuel line QD gets temperamental and won't flow fuel but that affects both cylinders. Check the fuel lines for any kinks. High Mileage or high wear? Sometimes the linkage between the two carbs can get worn or out of sync pretty badly. If you have the ability to run on fuel with the tank off, check the carb sync but that usually just causes rough idle or not smooth running. I assume you've pulled the jets and checked them for blockages, but typically rough or no idle is one jet, vs high rpm is another jet. I tend to just replace jets any time I even think there are jetting related issues. Make sure the needle or a jet hadn't come loose. The 950 motors are pretty durable and simple but they can be a bit of an issue. I don't have that many miles on mine but they have all been pretty hard. Feel free to PM any questions directly if it would help.
