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Just joined the forum. Hoping to get some advice.Had my 2007 S50 for almost 4 years now, bought it brand new in 2009. Always had to choke my bike hard to get it warmed up. Had some electrical problems initially and replaced the battery (which required extending my leads, neither here nor there), and it was running great.About a year ago I had some backfiring problems. I've always run some seafoam through my fuel occasionally to keep it clean.Last fall the bike completely crapped out on me. I replaced the spark plugs, and that seemed to help. I stored the bike for the winter, and I just replaced the battery. Getting plenty of power to start it, but the bike won't start after turning over many times. Hours of work and a few four letter words later, I start fooling with the choke cable (got about three notches from the choke knob) and if I pulled the cable directly under the right side of the seat, I got it to start for a few seconds. I think I'm on to something.I've seen in other threads that I may need to get inside the carbs and change the mixture. I'm not extremely familiar or adept with engines or maintenance, so please explain thoroughly for me! Any help is extremely appreciated. Just want to ride!Signed,S50 in need
 

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Pm'd. The choke, or enrichener cables (neither here nor there, lol) are seated on the front and rear carbs on the S50's and S83's. While I've never experienced it on the front carb, my cable has come unseated on my rear carb - leading to a constantly rich mixture. Poor starting, idling, acceleration, etc..was the result. Check the PM I sent, and wait for help from DrBob or someone else as equally qualified. I would not go into the carbs without a thorough understanding of how they work. Since you already admit that you're not too familiar or adept with engines, you've made a big step! There are many of us that have yet to admit to that truth....
 

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Discussion Starter #3
This sound right?

Pm'd. The choke, or enrichener cables (neither here nor there, lol) are seated on the front and rear carbs on the S50's and S83's. While I've never experienced it on the front carb, my cable has come unseated on my rear carb - leading to a constantly rich mixture. Poor starting, idling, acceleration, etc..was the result. Check the PM I sent, and wait for help from DrBob or someone else as equally qualified. I would not go into the carbs without a thorough understanding of how they work. Since you already admit that you're not too familiar or adept with engines, you've made a big step! There are many of us that have yet to admit to that truth....
Found this on another thread u sent me. Sounds exactly liked diagnosis and solution. Thoughts?"I'm just joined this forum and with the help of this thread, adjusted the idle mix on my 2007 S50. It is finally running like it is supposed to. My bike has 1700 miles on it and is in showroom condition. I was never comfortable with the way it ran. It took a LOT of choke to warm up, idled rough, backfired on decel and and sputtered and bucked when rolling off the throttle. Sometimes it would kick back and the driveline would slam like it was about to break, usually going into a curve or coming to a stop - not good. I drilled out pulled the idle mix covers and found both idle mix screws to be 1/4 turn from fully closed - tried turning them 1/4 turn each way and it had no effect on the idle. I even closed both screws and still no effect. Then I remembered the idle speed thumb screw. I had it screwed in as far as it could go just to make the bike idle. The bike had obviously been running on a higher speed jet all this time and not even using the low idle mix. After screwing out the idle mix screws about 2 turns, the bike finally started running smooth. I adjusted the rpms to really low so I could fine tune the idle mix on each carb. Took the bike for a spin and it is a new animal. I can cruise along now a low rpm without the choppy ride and jerking. It's really sad that these late model bikes are being sold with such a lean adjustment that they are dangerous to ride and most dealers and mechanics are unable or unwilling to make a simple carb adjustemt. Thanks for your help, especially High Desert Intruder, for sharing your knowlege and experience with us."
 

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Hmm...I guess the only person that can say "this is how my bike is running" is you, so if that sounds just like the problem you've been having then its a place to start.

During any of your hours of work and many 4-letter words did you remove the tank? I have a 1400 so some of the cables may be routed differently on mine... the carbs are similar though, and drilling out the caps to adjust the idle screws is a common fix for rough running. Double-check the idle speed thumb screw first if you haven't already.
 

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Hi, low, still doesn't get it running. When I manually choked one of the carbs, it started momentarily. That makes me believe the carbs are running lean, and the fix above may clear it up. I have seen that setting the idle screw to low rpms can allow for some finer tuning of the carbs for better long term results.
 

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And no, I haven't removed the tank yet. Those caps seem to be accessible, so I think I'll start there first.
 

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And no, I haven't removed the tank yet. Those caps seem to be accessible, so I think I'll start there first.
Ok! Keep is posted! Ask if you run into any questions when drilling the caps.
 

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Do not turn down the idle speed. The S50 needs to idle briskly, and it will run poorly if you set the idle too low.

Your bike ran until last fall, so clearly the factory fuel-air mixture is NOT the reason it will not run now. Something as obviously changed. Prime suspects are the rubber boots that hold the carbs to the cylinders. They can crack easily, letting air into the intake system and leaning out the mixture before it enters the combustion chamber, even if the carbs are fine. As these boots left the factory 6 years ago, it would not be at all surprising if they are cracked or no longer seated correctly.

Also check the choke cable adjustment at both carbs, and make sure the choke is actually working. If the choke knob does not stay where you put it and wants to suck back in, tighten the rubber ring it comes out of.

Other causes of a sudden lean condition are fuel flow related. Is the petcock in the correct position for the amount of fuel left in the tank? How old is the gas? Are the jets clogged from junk in the tank? Is there water in the fuel?

Eliminate all these things before messing with the carbs on a bike not currently running. The S50 is cold natured and is a touch lean from the factory by design, but there is no need to mess with the idle mixture screws unless you change exhaust systems and go to low restriction air filters. I put over 150,000 miles on one, and over 135,000 miles on another, and over 75,000 miles on a third S50, and never touched the carbs on any of them. The epa screws were intact on all three when I got rid of them, all had factory jetting, and other than some seafoam in the tank regularly none had ever had a carb cleaning. So if it ain't broke, don't mess with it, and find whatever is broke.
 

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Oh, by the way, the vs800 is notorious for being demonically posessed if the battery cables are not uber-tight. A star type lock washer under each battery cable bolt will help keep them tight, and make sure you crank down on the bolts with a wrench and not just a screwdriver whn you tighten them. My first one was a nightmare of electrical problems, stalling, and failing to restart at gas stations until a dealership mechanic told me about this. That 10-cent pair of star washers turned the bike from a total nightmare I was afraid to take out of town, to one of the most dependable bikes I ever owned that I visited all lower 48 on. And for the only time in my life when I wore a bike out I actually replaced it with the same exact model. And when they cancelled the S50 I ran out and bought a third while I could still get one. Funny how something as small as a lock washer can make that big of a difference.lol!
 

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Discussion Starter #10
I had electrical problems within weeks of purchasing the bike. Dealership couldn't help. Ended up Jerry rigging some lead extensions. Don't ask, but electrical is not the problem I'm 99.9% sure.Bike turns over, but won't fire. I wish you could hear it.The bike has always had some trouble/bucking running at lower speeds. Only started back firing and having poorer acceleration last August-ish due to what I assumed to be some eh-hem poor storage conditions. That's when I replaced the spark plugs. Seemed promising, but then started having almost zero acceleration as if no fuel was feeding in. I'm starting to think it may be a compounding of several factors including maybe the boots on the carbs. How would I go about getting at them? Remember my formerly stated mechanical qualifications.
 

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Bob! I'm glad you popped in - your mechanical expertise is well-timed and much needed! I didn't think about the boots at all...I'll need to replace them on my 1400 before I get it totally back together. If there is a problem with the boots, would a small amount of silicone help to prolong their service life or should new ones be sourced?
 

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Bob! I'm glad you popped in - your mechanical expertise is well-timed and much needed! I didn't think about the boots at all...I'll need to replace them on my 1400 before I get it totally back together. If there is a problem with the boots, would a small amount of silicone help to prolong their service life or should new ones be sourced?
You all wouldn't believe the Internet reading I've been doing. I'm almost convinced its the boots now. Or another air intake seal, but that may be my best point fix.Phoenix, I read elsewhere that silicone on the boots is not the best idea due to ability to cope with the high temp environment. A smear of high temp sealant on the boots is what I read should be done for maintenance. But hey, I'm just forwarding information,
 

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If the boots are defective, replace them with new. A little high temp sealant should be considered a temporary repair at best.

Rubber breaks down over time, especially around heat. But the boots can be kind of fragile even when new: when I bought my 1996 vs800 new the mechanic at the dealership cracked both boots while doing the 600 mile service. I was not happy.

If the bike was poorly stored, I hope you drained every drop of gas out of the bike and out in frsh mixed with a double dose of carb cleaner. The inner workings of the carbs will be clogged up, but as it has only been a few months carb cleaner may be enough. If not a visit to a mechanic for an off the bike carb cleaning may be called for.
 

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If the boots are defective, replace them with new. A little high temp sealant should be considered a temporary repair at best.Rubber breaks down over time, especially around heat. But the boots can be kind of fragile even when new: when I bought my 1996 vs800 new the mechanic at the dealership cracked both boots while doing the 600 mile service. I was not happy.If the bike was poorly stored, I hope you drained every drop of gas out of the bike and out in frsh mixed with a double dose of carb cleaner. The inner workings of the carbs will be clogged up, but as it has only been a few months carb cleaner may be enough. If not a visit to a mechanic for an off the bike carb cleaning may be called for.
Can new boots be purchased at any parts store, say advance auto parts, and what exactly am I looking for when shopping?
 

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Bit the Bullet

Took the S50 to a local, highly recommended shop. They cleaned/adjusted the carbs and serviced the bike for very modest fees. Running like new. Motorcycle.jpg

Here's a pic of the bike at my favorite spot overlooking downtown Birmingham, AL.
 

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Glad to hear you've got it up and running!
 

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They cleaned/adjusted the carbs and serviced the bike for very modest fees. Running like new.
Give it a drink of B12 or Gumout once a month, every 3 or 4 tankfuls and it should keep running like that for a long time.
 
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