Jan Luthe
New member
Runs only on one cylinder (drive belt side). Spark is good on both. Is it likely that fuel pump is pumping only on one line? How do I check it? Can I swap the fuel lines going to the carbs to see if the other cylinder will fire up? I did some preliminary carb cleaning (without disconnecting throttle, choke cables) but I don't want to mess with too much because I'm not sure how to tune/balance the carbs. Suggestions for a layman would be appreciated.
stanage
Member
Jan Luthe said:
If you think its the fuel pump, you could always remove the float bowl on the one carb, drain the gas and then see if the bowl refills itself.
Take a look at the pics, and then lookup some videos on cleaning carbs. Its not that hard, and after you do it once, you'll know what to do. If you take apart the carbs only take 1 off/apart at a time. And take your time. I suspect you have a clogged carb...
Jan Luthe
New member
Thanks for the reply Stanage. My carb is a bit different and I am concerned about syncronizing the carbs. I'll try to take the air box off without aking the carbs off so I can access the bowl and see if I am getting fuel and then go from there.
Take a pic of your carbs and post it. You may not have the stock setup in there if it looks different than the pics. These carbs are incredibly easy to clean, and no need to worry about synching if you put it all back where it was. I will wait until I see a picture before saying more.
Jan Luthe
New member
Ding: Looks like I got lucky. Took airbox off (remove seat, plastic shrouds around steering column, etc.). There was fuel in bowl of carb that wasn't working. Emptied fuel tank. Disconnected fuel lines and fuel came out when I cranked the engine. Disconnected throttle and oil injection cable at carb. Removed choke from dash and then removed carbs. Cleaned carb using compressed air, carb cleaner and fine copper wire in the nozzles. Turned 'air screw' in to count number of turns then took it out and 'cleaned' Also took off float and cleaned inlet needle valve.
Checked all jets by spraying in carb cleaner to see if it flowed thru. Put everything back togehter and seems to run fine (drove it for 5 minutes) I didn't take any jets out. All I took off was: bowl, 'Air screw' and float. Never did see any dirt but I guess I cleaned something out. Total time to do the job 4.5 hours. Thanks for your support and for the info thruout the forum. I'll take it for a longer test drive tomorrow.
Checked all jets by spraying in carb cleaner to see if it flowed thru. Put everything back togehter and seems to run fine (drove it for 5 minutes) I didn't take any jets out. All I took off was: bowl, 'Air screw' and float. Never did see any dirt but I guess I cleaned something out. Total time to do the job 4.5 hours. Thanks for your support and for the info thruout the forum. I'll take it for a longer test drive tomorrow.
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stanage
Member
Cool! Glad to hear its working and glad to see you took the initiative of taking apart the carbs. It really doesn't take much for snow machines to stop working. Running an older machine takes time, patience and some TLC 
Yamaha Nutz
New member
congrats on getting it going but you did do it the very long way air box comes out pretty easy on most yamahas if done right