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Discussion Starter · #21 ·
I don’t think the Airbox has any mods done to it, other than it probably is the California regulated version. I suppose I could maybe see if replacing the boots/adjusting them is possible, I am able to take the airbox off toollesly, do not know if that’s not supposed to be the case.
 

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Just looking at something that affected a couple of riders on the Shadow forum I‘m on. At 75mph, airflow was disrupted to their intakes and their bikes hit a wall. Once their air filter and/or intake were adjusted (returned to stock in one case), their engines could breathe at speed again.
 

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Is there a Restrictor fitted? There are a couple of videos on YouTube showing these. One guy has reduction rings fitted underneath the airbox and another has a restricted Ecu which he swaps out for a normal one. They restrict the bikes for young riders in the UK so they can ride the SV on an A2 licence. That would give you similar to the symptoms that you describe.
 

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I don't think a ,"Restrictor" is your problem as even restricted SV650s can well exceed 60 MPH.

I suspect your fuel flow has been hampered by debris in the fuel system/ Choke plungers not operating correctly or a partial vacuum @ the Fuel cap.

You can get another Petcock filer here,

SV650 eBay Petcock Filter

I've added an inline fuel filter to compliment the ones in the petcock and Carburetors.




Also use the Forum search option on checking your Choke Plungers.
 

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Discussion Starter · #27 ·
Hey hey everyone, just an update, sorry for the delay I really wanted to make sure this issue was fixed until I reported back.
It seems that the issue was the front cylinder wasn't firing fully or as efficiently as it should've. Air was good, compression was good, plugs were fine but when the carbs were taken apart the main pilot jet had such debris. My theory is that the fuel system was so filthy that until the petcock, pump and carbs were cleaned (in that order) the pilot jet would just get fouled no matter what. I am riding quite happily on my bike and now can stare into the abyss of mods, upgrades and creature features. Thanks guys!
 

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Hey hey everyone, just an update, sorry for the delay I really wanted to make sure this issue was fixed until I reported back.
It seems that the issue was the front cylinder wasn't firing fully or as efficiently as it should've. Air was good, compression was good, plugs were fine but when the carbs were taken apart the main pilot jet had such debris. My theory is that the fuel system was so filthy that until the petcock, pump and carbs were cleaned (in that order) the pilot jet would just get fouled no matter what. I am riding quite happily on my bike and now can stare into the abyss of mods, upgrades and creature features. Thanks guys!
That's why I posted that I've fitted an inline fuel filter. I recommend it on all 2nd hand/older Motorcycles to help stop any debris getting through to the Carbs/Fuel Bodies. It's a cheap safeguard and not hard to do :)

1/4" ( 6mm) fuel filters
 

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Discussion Starter · #29 ·
Thanks Strat, I saw one of those at my local shop and actually considered it only backing out of fear it might introduce additional fuel restrictions, however I think I will install one now that you mention it. Should it go between the petcock and the pump?
 

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Thanks Strat, I saw one of those at my local shop and actually considered it only backing out of fear it might introduce additional fuel restrictions, however I think I will install one now that you mention it. Should it go between the petcock and the pump?
Yes. Between the Petcock and the Fuel pump. I've used them on all my Motorcycles and never had a fuel restriction problem :)
 

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Discussion Starter · #34 ·
Last week during a morning ride I dropped my bike after I failled to recognize I was in second, (still a noobie), not only did it bend the shifter pedal a bit but also now it seems the problems returned. While installing the new parts plus a petcock (with an actual filter stem this time) and the previously mentioned fuel filter I actually took the time to clean out my gas tank. I didn't go crazy, no product, just a lot of rotating to get debris out and some gasoline for a brief flush. Needless to say there was a lot. When I got the bike it had sat under a tarp outside for some time. but never did it occur to me that maybe the fuel system all the way up to the gas tank would be an issue. I should've installed the filter the second my carbs were cleaned last-time, didn't even consider it. The problem is still there despite the total clean and I gave seafoam a shot but I bet the pilot jets clogged again. Right now I'm evaluating if I want to shell out money to get the carbs solely cleaned, or just buy a rebuild kit as one of the jets has never been touched (the one you drill out) I figure if I do that I should maybe also grab a choke plunger rebuild kit from rev too.
 

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It sounds like your problem is similar to mine. I rebuilt my carbs twice before realizing my whole problem was rust in the tank. And yes, I had an inline filter installed. Ultimately, I cleaned the tank with phosphoric acid and lined it with POR15, rebuilt the carbs one last time, and she's been running perfectly ever since.

Look up one of my old posts for the whole scenario. And sorry you dropped her. Always a learning experience.
 

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I placed a ceramic magnet in the bottom of my Corvette's fuel tank near the fuel pickup. I can't quantify how much it helps, but it does collect rust flakes.

Part of me wants to suggest that you buy a brand new tank if possible. I know they're expensive, but you'd be starting fresh, rather than trying to manage what you have.
 

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Discussion Starter · #37 ·
I don't think the issue is really rust. I don't know what rust looks like on a tank, but I am familiar with it on engine blocks and bare metal. The debris I've mentioned is more akin to dots or "particulates" of black. I'm also nearing a lot of sunken cost points on this bike as the initial buy in plus all the time and effort is adding up. I think the tank is probably fine, any remaining issues should get caught by the filters where previously there were none. Right now it feels like satisfaction is just being hindered by carburetor gremlins.
 

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I don't think the issue is really rust.
Neither did I until I filled it with Chemtool B-12, shook it, left it overnight, and found this the next morning.
Tableware Liquid Drinkware Dishware Ingredient


It did not look like traditional rust. And my inline fuel filter was lily white.

Here is what tipped me off. I drained the carb bowls into a glass bowl, let it evaporate a few days, then wiped the bowl with a paper towel. Here's the fuel after some evaporation. A bit cloudy.
Liquid Tableware Drinkware Water Fluid


Here is what I wiped from the bowl after all of the gas had evaporated.

Wood Beige Road surface Flooring Pattern


Point is, check the easy stuff first. Drain some fuel into a bowl and let evaporate. You may save yourself from rebuilding the carbs one or thrice. Good luck.
 
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