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Discussion Starter #1
Hi Everyone. Not sure if this is the correct place to post this. I didnt see any sub categories for fuel problems, anyway. Here is what I have: I have a 2007 V-star 650 classic. It has 2400 miles on the odometer currently.

HISTORY OF MY BIKE: Basically my family purchased this bike with 600 miles on it in 2008 and it sat around for 10 years. In the last 6 months i purchased the bike from my brother. Since it has been sitting around for 10 years and has not been winterized properly I went ahead and overhauled the carburetors. My brother had a mechanic work on the carbs before but my brother let the bike sit around so they got clogged again. I removed the carbs tore them down. I cleaned them the best I could with carburetor cleaner and chem dip. After I was done the bike ran great. I replaced the fuel filter, put a new oil filter, and new oil in the engine.

HERE IS MY PROBLEM: The bike will run fine. At full throttle it accelerates like it should and easily goes 80-85 mph if I wanted too. But sometimes after it sits for 8 hours or overnight after riding 20 miles it will start to stall, die, the engine will cut in and out. And vice versa if it runs bad and I shut it off and wait for a little bit will run like dream. It sounds like the engine is getting choked and it won’t accelerate. If I pull the choke out it while it is running bad it will start to run good, but I try not to use this much since this harms the engine. I have ran a few bottles of BG 44K fuel cleaner through the engine but it hasn't helped. The thing that I find odd is that some days it runs fine and others it doesn't. Is there something getting stirred up that is clogging the jets or float? Sometimes after it set it will work fine like it has no problems.

Any help would be appreciated and thanks in advance for you taking the time to read all this! Sorry if it was long I just like to be as detailed as possible.

-Ryan
 

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Super Moderator "Loose Nut"
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Yes, sounds like a fuel issue. Let's start with eliminating a few causes. What does the inside of gas tank look like? Clean or something like this?

 

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I dont know if the 650 is prone to vapor lock - pulling a vacuum in the gas tank because the vent is plugged?
 

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Discussion Starter #4
Les-I took the cap off and I didn't see any rust of metal flaking, at least at the top of the tank. I might let the gas run down a little bit and put my scope inside to see if the sides and the bottom are in the same condition.

KCW-I was thinking about this the other day after I read some articles online and I was curious as well. I wonder where the vent is at. I have never heard any sound from the tank when I remove the fuel cap, like suction or a "whoosh" as if air was being released.

I might have to do some testing. When my motorcycle acts up again I am going to pull over and then remove the cap then put it back on. Then fire up my bike and see if it runs better. If it improves then I may have vacuum issue. Yesterday morning it ran ok but was still not 100%. If i eased the throttle it would get up to speed. I went to work then came back and rode it on my lunch break. It ran about the same. Then after work i went home and it ran like it should.
 

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Discussion Starter #6 (Edited)
Yeah that is a possibility. I do hear something clicking when I turn the ignition. If that's the fuel pump then its working. How good it is working is another question. May not be putting out the correct amount of pressure. I should look into that as well just to see if its in working order. Does anyone know what the PSI should be for the fuel pump?
 

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the 650 has a fuel pump because the big 4.2 gallon gas tank bottom is below the carbs, so to get all the fuel out of the tank it uses a low pressure fuel pump.

I dont know what the pressure should be, if you pull the line off the carbs and just turn the key on, it will run for about 3 seconds (if you dont start the bike). If fuel is flowing out when you turn the key on, it should be ok.

Since your problem appears to be intermittent, that will only tell you if the fuel pump is dead, or you happened to catch it at a good moment.

You have cleaned the carbs, when you had them off did you have the air filter assembly all apart? if it was sitting with the carbs off its possible a mouse or something got into the air filter and built a nest in the intake box. I have seen this happen many times on cars.

Also check your air filter, if its not clean like white paper it should be replaced, but with only 2400 miles on the bike I doubt its dirty. If it is dirty that would not cause an intermittent issue.

Its still possible there are some passages in the carb that got missed when it was cleaned - some need to be poked out with a hi-E guitar string or a similar very thin piece of wire. There are a couple paths the gas takes thru the carbs depending on the throttle position, and they all need to be cleaned.

Its also possible you have an ignition problem, but normally if a bike has been sitting for years, its ethanol fuel that has turned into jello somewhere in the fuel system.

I dont see any mention of the fuel filter. I thinks its alum on the stock 650, so you cant see if its full of ethanol jello. If it was not replaced when the carbs were cleaned then it will dump more goop into your clean carbs.

It worries me that you have run a few bottles of BG 44K thru the bike. I would think one bottle would be enough for 20 gallons of gas or more. If you poured a whole 11 ounce can into your 4 gallon tank, Im not sure what that would do, if it would cause any harm. I use SeaFoam on my bike, and its 1 ounce per gallon of gas. I know of people that have poured a whole 16 ounce bottle of seafoam into one 4 gallon tank, and the results were not good.
 
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