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Discussion Starter #1
Hey everybody. I wanted to get your thoughts on an issue I ran into on the last ride of the season back in November 18.

Had been riding for about an hour and slowed down in traffic. I pulled in the clutch and the bike idled really low and then died. I pulled to the side and tried to start it up again but it would just crank and not catch and start up. This same issue had happened a couple of times in the past few months but would always start back up after waiting a few minutes. This time I tried starting it intermittently for at least 30 min and all I got was sadder and sadder cranking. I was just about to call for a tow when I tried again and it started up. I was scared to let the revs get too low again so I rode the rest of the hour ride home never letting it fall into an idle and kept it revved the whole time. Not fun.

What do you make of this? Overall the bike has been quite reliable but I don't like this dying-after-idling-low that has become more common. My newbie assessment is that this seems like a fuel supply issue. The carbs were cleaned about 6 years and 30k miles ago. Could the carbs be what is causing the issue? Is it time to take them out and clean them? Any help/wisdom would be greatly appreciated!
 

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I suggest checking the basics first. Is air filter white, if not change it. When was last time you changed fuel filter? When was last time you changed plugs. How old was gas? Was gas allowed to age in the fuel system. Are the rubber fuel lines in good shape? They do get old and collapse with age. Take care of the simple things before you go pulling the carbs. Carb rebuild is actually pretty easy but might not be the issue.
 

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Discussion Starter #3
Thanks so much for the tips lesblank. Makes sense to check out the simpler things before digging into the carbs.

Just took the bike out of storage for the season and was encouraged that it started up easily and ran well for the 30 min drive. I am going to check into the things you mentioned (especially the fuel filter and fuel lines) and may still clean the carbs because it cant hurt, and it sounds like a fun project.
 

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actually cleaning the carbs can hurt

there are a lot of threads started by riders here who decided to clean the carbs or put bigger jets in the bike, and had an aweful time of it, sometimes to the point where the bike would not start, would only run on one cylinder, and for some of them it took weeks to figure out what went wrong and get the bike running well again.

I have a reputation here as being Mr SeaFoam, and that is fine with me. If you run a carb cleaner thru the bike anytime its running a bit rough, that is the time to do it, and its normally all you need. As long as the carbs are not full of goop because the bike got left sitting for months or years with E10 gas, the ethanol broke down, and totally plugged some of the jets or fuel passages... as long as the bike run reasonably well then carb cleaner will flow thru the jets and PMscrew and idle passages, and wash them out as it flows thru.

SeaFoam is about $8 for a 16 ounce bottle at Walmart. You put 1 ounce per gallon in the tank with fresh gas, and just ride. To make sure you are getting the main jets flushed, get on the throttle when you have a good chance, taking off from a stop and going up a good hill. The main jets do not flow till the throttle is twisted almost half way, so crank it WFOpen as much as you can, without going nuts or crashing the bike.

If you run thru a treated tank and the bike is not running great that would be unusual. When I got my Royal Star the previous owner was only riding it once a year (to get it inspected). The gas in the tank looked like coffee. I dumped that all out, but it still took 2 tanks of SeaFoamed gas to get the bike running well. With a big engine like the Royal Star 1300 V4, you gotta be on the interstate to twist the throttle WFO and let those 74 horses run in 4th gear, so it took a while, but the bike runs great now.

If you always use a fuel stabilizer when the bike will not be used for more than a month (SeaFoam is good for that too), and you get some carb cleaner in the tank any time the bike feels a bit off, you should never need to take the carbs apart and clean them manually, unless you somehow get a tank of gas that is full of crap.

You dont have to use SeaFoam, there are several good carb cleaner fuel additives and fuel stabilizers. I just happened to use SeaFoam the first time I needed to store the bike over the winter, and it works great for me, so I have no reason to try them all.
 

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I find that I must diverge a bit from the opinions in the video about SeaFoam. Sure, it won't do much if your carbs are REALLY gunked up. But it cannot hurt to try so I am most definitely not so dismissive of the product. Try it first and see if it does the trick for you.

If not, then go with plan A. Pulling carbs, dis-assembling and cleaning is the definitive, most effective way to clean the system but not necessarily a "required" way. Nor a desired way. SeaFoam is the least labor-intensive thing to do while pulling and cleaning carbs is the most labor-intensive thing to do.

Just as lesblank says, do the simple things first. I'll add to that and say do the least labor-intensive thing first, also. You might wind up having to go the other way anyway, but maybe not. The stuff worked just fine for my bike after a three-year period of non-activity. It got me on the road just fine although I did have to wind up pulling the main jets to clean. At least I didn't have to pull the carbs to get to my jets.
 

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SeaFoam is kinda like cats. People either like them/it or not. Similar to brother KCW, I am also a devout disciple in the Church of SeaFoam.
 

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Discussion Starter #8
Happy summer everyone.

I wanted to give an update on the issue I have been having with my 05 classic (stalling while it is running and then taking a while to be able to turn back on- like it is out of gas even though the tank is full).

I thought perhaps the carbs were to blame for this issue so I cleaned them. During the process I did not find any major blocks or other things that might be causing a problem.

I was riding the bike last week and the same problem happened again! It stalled when I was riding through a tunnel in Boston so I had to stop in the one foot wide shoulder with traffic driving by (not fun/safe!). As I tried to turn it back on it would crank but not turn over. After a few minutes of trying this, it caught and turned back on and I was able to ride home.

I dont know what is going on here! Its cranking and not catching like there is no gas even though the tank was half full. I know now that the carbs are clean so that is not the issue.

The random and intermittent nature of this issue is not helping my peace of mind. Any ideas what is going on?

Also, a few specific questions/responses:
1. lesblank- Regarding some simpler things: air filter is new. new spark plugs last spring. fuel lines are in good shape. gas was treated with stabilizer before winter hibernation. will change in-line fuel filter this month.
2. Does Startron Enzyme Fuel Treatment do the same thing as SeaFoam? I have been using Star Tron.
3. Is it possible something with gas cap venting could be causing the issue? I read something about that.. Thoughts?

I really appreciate the help everyone. -Mike from Boston
 

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the situation you are describing does fit vapor lock in the tank

the fuel pump sucks down the tank after riding for a while, the vacuum keeps it from pulling out any more gas - the bike stops... You sit there for a while cranky and cussy and angry and HELLO! It starts up again (the tank slowly pulled in more air thru the blocked vent, or maybe pulls in air backwards thru the carbs and fuel pump with the pump off).

The simple test, if it happens again, remove the gas cap and put it back on. If it starts right up its vapor lock.

Another possibility is something is heating up and failing when hot, like the ECM, ignition components, or there is a random loose connection somewhere in the ignition circuit. If its the ECM, it gets hot, drops out, and will not fire the plugs till it cools off.

Testing an intermittent problem is difficult. You could get one of those in-line spark testers that will show you if your plug is firing, not sure if you could leave it on one cylinder all the time - then next time it quits see if you have spark. If not download the free factory service manual pdf file and goto the 'no spark' debug tree. But again, its intermittent, so it will be hard to tell when you have found the problem, vs the hot thing cooled off and started working again.

It could also be an intermittent fuel pump, randomly shutting off your fuel supply - test would be to pull the fuel line off the connector, turn the key on, and see if the go-juice flows out? If not then you need to determine if its the pump, or the power connections to it.

I googled Startron Enzyme Fuel Treatment

its about twice the cost of seafoam

they make some steep claims, like only needing 1 ounce to treat 6 gallons of gas,
that it can restore gas that has already gone bad...

dont know if those things are true - I would not start a bike with fuel that is more than a few months old, less risk to drain the tank and let it evaporate away, than to try to save $5 for 2 gallons of goopy gas.

most fuel additives are 50% lighter fluid (napthanol?)
 

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POOGS (Phantom Out Of Gas Syndrome) is a common illness on my species of Vulcan, for example. The tank will get about half empty and the bike acts like its out of gas. Opening the gas cap kills the vacuum created inside the tank and is a temporary fix. The entire venting system needs checking/cleaning. Its not difficult to do on a Kawasaki and I don't imagine it'd be really different on yours either.

It drives you nuts, just like KCW was alluding to, and it seems to happen at random times. But its not really random. You've noticed that it happens when the gas level is about the same each time, half way just like on my Vulcan. Then (assuming that POOGS is your issue) then that particular volume of empty-tank space is the threshold where the vacuum overcomes any attempt to pull fuel out of the tank.

If it is your venting system being clogged, remember that there are very small air passages in it that don't take a lot to stop it up. Perhaps a blast of pressurized air will clear it. You can buy cans of pressurized air in places like Office Depot. They're generally used for cleaning the keyboard that I'm using to type this.

Another place to look is to see if underneath the bike there is a rubber hose that just seems to be hanging there in mid-air doing nothing. If so, chances are that that is the bottom end of your venting system. Its placed there so if the tank does need to out-gas excess fuel (in case you over-filled the tank) then it'd come out underneath in open air and not somewhere higher, and hotter. Sometimes this rubber hose can get goobered up with random road snot, thus clogging it up. Just snip off a half inch or so to open it up for air flow.

The venting system is used two ways, as you can tell from what we've written: It vents excess fuel/fumes out when needed but also just as importantly allows air IN so as to prevent the vacuum that would naturally form inside the tank. Also the venting system is separate from the fuel system so perfect fuel systems can't/don't prevent venting issues.
 

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^ I have taken the gas tanks off my 650 and Royal Star, and Im sure there are no other hose connections except the fuel line off the petcock. Im certain these two bikes at least have the vent in the gas cap, only because I dont see where it could vent anywhere else. The exception is a California bike with its emissions vapor control junk - never seen one.

Ive never seen an exploding drawing for the vstar gas caps, so I cant help you debug vapor lock, if that is what you find to be the issue - again: just take the cap off when it quits, that will let the air in, and if its starts up thats what it was. I would expect it would fight you to come off if there is a vacuum in the tank.
 

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Exactly which model bike do you have?
 

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he said its a 2005 classic, cant tell from the one photo he posted in the intro thread if its a 650 or 1100

they are both very similar designs
 

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Discussion Starter #14
Hi KCW and 750 Chris-

I REALLY appreciate the help.

Sorry I wasn't more specific about my bike. It is 2005 1100 Classic California model (XVS1100ATC).

From what you have described my situation does match up with POOGS, so I am thinking it may be caused by a vapor seal. The next time when/if the problem happens I will immediately take off the cap and see if it solves it. However because I have the CA model, it seems to me that my situation is a little more complicated.

Looking at the exploded diagram of the fuel tank (https://www.partzilla.com/catalog/yamaha/motorcycle/2005/v-star-1100-classic-xvs11awtc/fuel-tank) my tank is connected to the petcock but it is also connected to an outlet at the back/bottom of the tank. I had the tank off a few weeks ago and can confirm that second outlet is there.

So what I am wondering is, because it seems there are two components to my bike's ventilation system (gas cap AND lower ventilation system), if I take the cap off next time this happens will that confirm that there is a vapor lock problem? If there is an issue with the lower ventilation system (ex. clogged tube) then taking off the cap may not solve the issue right?
 

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the petcock goes right to the fuel pump, so as long as there is not a partial vacuum in the gas tank nothing will stop the fuel from flowing ( you take off the cap, vacuum is released...)

the other hose is the complex version of the fuel vent that is in the gas cap on everyone else's bike.

Your bike is suppose to let air in as the pump pulls out fuel, and when you park the bike in the hot sun its suppose to vent the pressure thru a charcoal canister or some other similar device to keep the vapors from the atmosphere. If that is not working your tank cant breathe, and you get vapor lock.

If you then pop the gas cap normal air pressure will return and the fuel will flow. You might need a screwdriver to pry it off after you turn the key, if the vacuum is strong in the tank.

Let us know what happens next time it quits, if popping the gas cap gets it going, something is amiss with the vapor control system.
 

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Yeah. What he said. Just note the popping the gas cap will be only a temporary thing until the vacuum pressure, once again, becomes evil.

So, it'll get you down the road more but will not take care of whatever it is that is clogging the overall system.
 
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