Snowmobile Repair: Yamaha Question, external coil, float bowl

Question
I have a 1989 Phazer pz480, having an intermitten promblem.  Sled is loosing power after running the sled for short period of time.  If I bypass the safety throttle switch the sled runs properly.  But after short period of run the problem returns. As long as I keep repeating this process the sled will run. The sled idles fine but when the throttle is applied the machine boggs.  Then I apply the change and sled will run again fine for a short time. The sled only has 3000 miles and has been well maintained.  Replaced fuel lines, external coil, fuel pump, fuel filter and lots of money to find the promblem. Please help......

Answer
Hello Rob,

 It gets real irritating when a sled does that. Sounds like your sled could have a variety of problems. Here is what I recommend. Take your CDI off and have it tested, it shouldn't cost much to have that done. Your safety switch on the throttle really needs to be replaced, from what I can tell, so that would be a good idea. Last of all, it could be, and is rated the number one snowmobile problem when getting a sled out after setting up all summer. That would be that your inlet needle inside of the carburetor is sticking. The reason I say that is because when you go to bypass the switch, that would give the sled enough time to get some gas into the float bowl. It would be a good idea to take the carb off, and clean the float bowl really well. a repair kit for the carb would be ideal. Also, be sure to use the proper spark plugs, they are NGK BR9ES gapped at: .028. If you need any OEM parts for your sled you can get them here:  http://216.37.204.202/yamaha_oem/YamahaSnow.asp
Also, check all of your wiring over to make sure there isn't a short or open circuit somewhere, such as disconnected plugs on the wiring. Hope this helps to get your sled running properly. Let me know if I can help with any other questions at all. Best of luck to you with the Yamaha! --Arcticatman