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Discussion Starter #1
Ok, so I know there are no known surging issues with the 2005 ST3's, but mine surges just the same... So, I ran a can of Sea Foam through her, with little effect. Today, riding home from work, I ran a little low on gas, and low and behold, the low gas light came on, and the surging smoothed out!

So I rode her for 15 miles like that; no surging. Stopped and filled her up with 93, and the surging started again.

So, what's the answer to this puzzle? This weekend I'll run her low on gas and pull the fuel pump to see if anything looks funny. Ive got a gasket and a fuel filter as I was going to try this anyway.

But what does the collective wisdom think about this? Why would the fuel level contribute to surging?
 

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Could there be a venting problem in the gas tank which is minimized when the fuel level drops below 4 gallons and the warning light comes on? Check all the lines coming in and out of the gas tank to make sure all of them are secure and none is plugged or crimped.

If your bike still has the charcoal cannister, check it to make sure it is not saturated with gas, which has been reported to happen when the tank is not properly venting or is over filled.
 

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Discussion Starter #3
Canister

So, if the canister is saturated with gas, is there a way to dry it out, or do you have to replace it?
 

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Could there be a venting problem in the gas tank which is minimized when the fuel level drops below 4 gallons and the warning light comes on? Check all the lines coming in and out of the gas tank to make sure all of them are secure and none is plugged or crimped.

If your bike still has the charcoal cannister, check it to make sure it is not saturated with gas, which has been reported to happen when the tank is not properly venting or is over filled.
I had the same thing happen to my bike when I overfilled it a couple of times.
 

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So, if the canister is saturated with gas, is there a way to dry it out, or do you have to replace it?
AFAIK, the routing of the vent lines was changed in 2005. Overflow gas no longer goes to the cannister like the 2004 models If I fill mine past the filler tube, and put her on the side stand, I will get gas dripping out of the overflow hose, right side of engine, "under" clutch.

Did the bike ever send a EOBD error code, ie amber light come and stay on causing a starting delay/problem?
 

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Discussion Starter #8
Ssurging Solved!

I was so sure it was a fuel system problem... I replaced the fuel filter, inspected all the hoses, everything looked real pretty. Buttoned her up and went for a ride. She had smoothed out some, but was still rough.

Came back and replaced the chain (another piece of maintenance I had planned). And wow! the old chain had stretched just over a full link (one full plate)!

I bought her knowing I needed to replace the chain, but that was a real surprise. Anyway. With the new chain on, she's as smooth as a baby's behind! Just wonderful!

Now, why she seemed to smooth out when the fuel got low, I just don't know.

But she's fine now...
 

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Hmmmmm.......Dunno about the chain part, but I like it that you replaced the fuel filter. I wonder if it wasn't just the intermittent flow of fuel from a clogged filter that was causing your surge? With the new filter and a smoother/increased flow of fuel, it may have worked loose some additional sediment in the line. I'd seriously look at flushing the tank in the off-season. Might be that you just got a batch of bad gas. Glad you're up and running...when it's good, it's great ;)
 
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