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Discussion Starter #1
This might be related to my previous post below about the leaking petcock but I think it might be a totally different problem. Basically, I've removed the petcock diaphram so that fuel flows freely down the lines. No more vacuum hose. I sealed it with a makeshift gasket so NO MORE LEAK either. I installed a clear plastic filter on each line right out of the petcock. Here's the problem... the rear-most fuel filter fills up nicely while the front-most stays almost empty. Now, if I tip the tank forward then the front filter fills up all the way but the rear one empty's out. When I take her for a ride she'll last the 3 minutes perfectly and then starve. I'm assuming she's living off the float bowls but not replenishing. When I watch the filters closely, you can clearly see the fuel easily flowing into the full filter but not the empty one. When I tip the tank it's vice versa. My question is, by installing the filters does this mean that the suction from the carbs that was once enough to draw gas is now too small? Do I need to somehow increase the 'pull' power from the carbs? And why aren't the lines drawing fuel equally from both sides of the petcock... only from the side which is tipped? I'm pretty sure there's no blockage in the petcock since I can easily blow air through one and out the other and, like I said, when I disconnect both lines fuel flows quickly from both. BTW, here's a quick little test I did. I waited for the bike to start starving and watched as the one filter emptied. I shut her off and waited to see if any fuel flowed into the empty filter. Nothing. But as soon as I disconnected the filter from the petcock a gush of fuel came out. Any ideas would be most helpful!
 

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Calif Rider
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Have you tried to swap the filter to see if there is a problem with the rear filter. You may have done this already.
 

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Discussion Starter #3
Yes I did. As soon as I swap them and start the bike, the one that was full starts emptying and the empty one starts to fill. With about 30 seconds they look exactly like before the swap.
 

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Is one filter higher then the other?
 

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:confused:

Curious, although the only thing I can think of that can affect carb pull is that they might be out of sync. However, the tipping of the tank makes me lean in Piro's direction. Were the carbs sync'd before you put the filters on?
 

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Old Truck Junkie
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Try opening the fuel cap while bike engine is running. Also tap the carb with a wrench and see if the fuel flows better.
 

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Discussion Starter #7
The filters look the same height although the petcock tilts slightly downwards towards the back of the bike because of how these gas tanks are. The bike ran PERFECTLY up until I decided to pull the tank to clean it. It was all rusted (REALLY BAD... I'm talkin thick rust all over, no clean metal). I ride 20 miles to work and back and never had a problem. I just figured it was only a matter of time before the rusty tank caused trouble. I tried to clean it but still looks like crap inside. Because of this I installed the filters. I also took apart the petcock and cleaned it (that's probably when I damaged the diaphram and had to toss it). I didn't even touch the carbs though, so I don't think they could have gotten out of sync. I tried the fuel cap but no go. The only way to get even flow is to lift the tank about 4 inches in the back so the petcock is parallel to the ground. But obviously I can't ride like that. I'll try the tappin'.
 

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and the Adventure Cycle
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There was mention of being sure to use hi-flow filters when adding them to a normally functioning fuel system, not sure if that'd be an issue with a modded petcock like yours though?
Have ya tried switching the line itself (after the filters) from the front to the rear, and rear to front? Don't know what that'd prove, but couldn't hurt to try.
 

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Discussion Starter #10
Hmmm... That's a good point. I didn't think about high flow. That could be an issue. I'm almost tempted to remove the filters for just a quick test but I'm too afraid with the condition of that tank. I did notice last night that she performed a lot better, didn't completely starve when i took her out. Just a little more rough than normal. I'm wondering if the system just needs a good run just pumping gas through to get some gunk moving out. I'm definitely gonna try the seafoam and see what that does. Another thing I'm wondering is if the added length of the new hoses and filter has affected the carb sync. I'll check into that too. Just wanna say thanks for all the help I've been getting. First bike and all, it's good to know we have such a great community!!!
 

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Premium Member
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Something to try...

plumb the lines differently. Use one big HIGH FLOW filter, plug up the other gas port, use a tee on the side that works.
 

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Gnarly Jokester
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Think hyper hit the nail on the head. High flow fuel filters work better, they don't have to be the most expensive ones with the highest flow, but must be high flow.
 

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Discussion Starter #13
PROGRESS!!!! I capped off the front petcock valve and left only the rear fuel line/filter assembly. Next, I inserted a tee AFTER the one remaining filter and connected the fuel lines. So now I have an uninterupted, UNVACUUMED fuel flow exiting ONE side of the petcock into a FILTER, teed off into the two fuel lines. I added a 3rd of a small can of Sea Foam, started her up and rode her around my block for about 5 minutes. She didn't skip a beat!!! I'm still not gonna exhale since a 5 minute ride is NOT a 25-mile / 30-minute ride to work, so I'm gonna let her sit with the seafoam in the lines overnight and try to take her out again around my block tomorrow for a longer while. If I break down I can always push for a good 10 minutes. I was just curious... why do the petcocks have that vacuum valve to allow/inhibit fuel flow. It seems like this (without a diaphram and just turning off the valve when parked) there are less things to have broken. Anyways, this is just one big bandaid. Once I get a new tank and petcock this whole McGuyver rig will come out. I just NEED to ride in the meantime.
 

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Discussion Starter #15
UPDATE: Well, I'm writing this from work!!! Yep, I made the 25-mile trip, without a hiccup. I think I'll be ok til I get the $ and time to get a new tank installed. Thanks, all, for your support!
 
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