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Old 01-12-2010, 01:48 PM   #1 (permalink)
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Sno Scoot carb question

I'm trying to get my buddies Sno Scoot running after he attempted to clean the carb. he pretty much dismantled the whole sled and I'm trying to put it back together. I've got everything in place, but one thing that I can't figure out. There is a port on the carb(looks like a vacuum line would slide onto it) that is currently vented straight to the atmosphere. I have the shop service manual for the Sno Scoot and the pictures in there don't show this port at all. It is clearly not there in the pictures. Should I just plug it or is there something I'm missing? I hope there is someone out there that still knows something about these little sleds!
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Old 01-18-2010, 07:03 PM   #2 (permalink)
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its just a vent. mine has the same thing but mine has a small black hose on it.
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Old 01-19-2010, 01:40 PM   #3 (permalink)
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I am really scratching my head over this one. Everything I know about carb theory tells me that there shouldn't be a vent there. It would be like having a hole in the boot between the carb and the cylinder(which has caused many people great frustration on anything that has a carb boot) Introducing more air into the air/fuel mixture after the carb just seems crazy. I wish the factory service manual weighed in on this one. So does your scoot run properly with that vented? I was going to plug this one since I have no other info to go on.
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Old 01-21-2010, 07:41 PM   #4 (permalink)
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I was afraid to leave that open, so I plugged it and tuned the sled like that. I didn't want to run the risk of introducing more air into the mixture, leaning out the air/fuel mixture and blowing it up. It runs fine now, but I'd like to know why that port is there in the first place.
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Old 02-04-2011, 02:34 PM   #5 (permalink)
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That is a vent port it is supposed to be there. if you plugged it I'm guessing you compensated by opening the air screw more. It is supposed to be there with a hose on it as you were told earlier.
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Old 02-04-2011, 04:49 PM   #6 (permalink)
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We've been running it with that vent closed for the last year, plug looks fine. We just lined it up against another scoot last week and they were dead even after nearly a mile. Next time I have the shroud off I'll unplug the vent and re-tune it.
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Old 03-01-2011, 09:20 AM   #7 (permalink)
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Quote:
Originally Posted by tommy54 View Post
I'm trying to get my buddies Sno Scoot running after he attempted to clean the carb. he pretty much dismantled the whole sled and I'm trying to put it back together. I've got everything in place, but one thing that I can't figure out. There is a port on the carb(looks like a vacuum line would slide onto it) that is currently vented straight to the atmosphere. I have the shop service manual for the Sno Scoot and the pictures in there don't show this port at all. It is clearly not there in the pictures. Should I just plug it or is there something I'm missing? I hope there is someone out there that still knows something about these little sleds!
I have this exact same question. It is very strange to me too. But I can't this sno-scoot to run properly. I cleaned the carb very carefully. I got it to start really well cold or hot. But it won't idle properly. It revs up and then idles nice and then dies down and stalls. or it might just almost stall and rev up again and idle right again. Do you have any idea's. Also do you know what is under the welch plug on top of the carb?? because I didn't remove it. It is missing on all the diagrams too. maybe it is dirty under there I have no idea. please help if you can. oh yeah I should mention that it runs great when it's being driven.
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Old 03-01-2011, 11:20 AM   #8 (permalink)
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Check the pilot again. Be sure The filter in the tank is ok. When the filter begins to break down it plugs every thing. If you don't remove the wench plugs its not easy to get it clean.
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Old 03-03-2014, 10:26 AM   #9 (permalink)
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@yamagirl are the wires for your throttle override sensor plugged into te carb? If so
Disconnect them and plug the ones off the harness to each other, that should help.
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