Oil pump line check valve allows gas to leak out?

I suppose anything is possible. But a dirty pilot would cause a no idle situation not high idle right? I just cleaned the carbs about a month ago. I'll keep my eye on it.
 
steveg_nh said:
I suppose anything is possible. But a dirty pilot would cause a no idle situation not high idle right? I just cleaned the carbs about a month ago. I'll keep my eye on it.
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You would think that a plugged pilot jet causes low idle because of the lac of fuel, but it does the exact opposite. It creates a lean condition therefore increasing the idle. Easiest way to check is while it's hanging, flip the fuel enrichener (choke). If the idle drops right away, this points towards a lean mixture. Of course there is more then one reason for lean idle, either not enough fuel or too much air. An example of this is worn crank seals or cracked carb boots. Keep us updated if you find anything.

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Good info thanks. I only said that because last 2 times my sled wouldn't idle the pilot jets were clogged.

Carb boots front and back are good. And tight since I just looked at them Friday. I've always had this off and on over the years with this sled and have read tons of others with it. It only did it twice and was fine at the end. Two things bring it right down. A quick flip of the choke or a little tap of the throttle.

I'll see how it is next time.
 
I'm not saying dont check your carbs. Brethren a plugged pilot will not cause a idle hang. A lean condition yes but not a idle hang. In fact if plugged bad enough won't even idle off choke and will just bog out. A rising idle is from a air leak. A idle hang happens when pipe is hot and your comming down in rpms to stop. Usually after lo g run or riding midrange to long. The pipe will hang up and not want to idle down. A quick blip of choke or throttle brings it out of that rpm and it idle down. Best fix is set idle at 1200 ish and blip throttle comming to a stop. The Yamaha viper "idle hang" is not a lean condition. But do double check that carbs are clean and no leaks. That damn idle hang comes and goes for no particular reason. Just pay attention to your sled. I've checked plugs a 100 times with a chop at idle hang and never lean!
 
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super1c said:
I'm not saying dont check your carbs. Brethren a plugged pilot will not cause a idle hang. A lean condition yes but not a idle hang. In fact if plugged bad enough won't even idle off choke and will just bog out. A rising idle is from a air leak. A idle hang happens when pipe is hot and your comming down in rpms to stop. Usually after lo g run or riding midrange to long. The pipe will hang up and not want to idle down. A quick blip of choke or throttle brings it out of that rpm and it idle down. Best fix is set idle at 1200 ish and blip throttle comming to a stop. The Yamaha viper "idle hang" is not a lean condition. But do double check that carbs are clean and no leaks. That damn idle hang comes and goes for no particular reason. Just pay attention to your sled. I've checked plugs a 100 times with a chop at idle hang and never lean!
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I admit I don't have any experience with aftermarket exhausts, but I can tell you that a partially blocked pilot jet will cause idle hang. The mere fact that a blurp of the throttle or a flip of the fuel enricher brings the idle down tells you the mixture is lean while hanging, and adding a shot of fuel brings it down. I also have personal experience of idle hang that was cured by cleaning the pilot jets with a wire. We might have to agree to disagree, but as you stated it doesn't hurt to clean the pilot jets, it's relatively easy place to start and doesn't cost anything. It's also worth mentioning that carb cleaner and compressed air is not enough to clean these jets. You have to get a wire in there and scrape the inside of the jet. Sometimes it's easier to replace them

Cheers

Sent from my SGH-I337M using Tapatalk
 
super1c said:
I'm not saying dont check your carbs. Brethren a plugged pilot will not cause a idle hang. A lean condition yes but not a idle hang. In fact if plugged bad enough won't even idle off choke and will just bog out. A rising idle is from a air leak. A idle hang happens when pipe is hot and your comming down in rpms to stop. Usually after lo g run or riding midrange to long. The pipe will hang up and not want to idle down. A quick blip of choke or throttle brings it out of that rpm and it idle down. Best fix is set idle at 1200 ish and blip throttle comming to a stop. The Yamaha viper "idle hang" is not a lean condition. But do double check that carbs are clean and no leaks. That damn idle hang comes and goes for no particular reason. Just pay attention to your sled. I've checked plugs a 100 times with a chop at idle hang and never lean!
Click to expand...

Too lean the plugs will look a bit burnt right, kind of brown? I'll check, but ever time I've checked they've looked pretty good. Of course things can change. But what you mention about the idle at 1200 is what I remember, both from reading on here, and from my mechanic. That's why it was set there, to improve the idle hang. This sled has done it since the day I got it. It hasn't been an issue, until now, and I upped the idle to like 1500-1600. I'll drop it and keep an eye on it.
 
I believe brown would be nice to see on plugs, lean would be light and flaky, rich would be black and or wet
 
Just to update this on the idle hang situation. It did it a few times today so I pulled over on the trail and lowered idle to 1200-1300 as it was before today. Rode 80 miles and didn't hang once. :) totally forgot to keep it there when I raised it before.
 
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