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Discussion Starter #1
Okay so I have my bike put back together after the shop cleaning my tank. So I go to run it today and it runs just fine in Prime positions but when I turn it to On it just bogs down and eventually dies. There is plenty of gas in it. So I figured it might be a vacuum leak so I am taking a look around at the Vacuum Line and notice it goes from the Petcock to the other side of the bike just under the air filter housing. (See Picture) I am not a mechanic and I am new to bikes but from what I have read this doesn't look right. Shouldn't this go to the carb somewhere?
 

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I believe the vacuum line from the petcock goes to the back of the carburetor. I seem to recall that there were only two hoses coming out of the back of my stock airbox when I modified it, and that was for the crank case breather and the EPA stuff. I'm not sure what your hoses go to, but I could assume it is EPA related. California models came with an additional hose from the airbox to an evap canister I believe.
 

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Discussion Starter #4 (Edited)
SO I pulled the tank back off and there is the line that runs from the petcock to the air housing as I mentioned but there was a tee in the middle and a line going to the Carb but it had come undone and the hose is shredded. Do I need this T adapter in there? Does a line need to run to the air housing? I am a little pissed off at the shop.


**Update** So I replaced all the vacuum hoses and left the T in that goes to the air housing. Just took it for a short ride and it is running great!
 

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Glad to hear you got it up and running. I think the other hose from that T fitting goes up to your EPA valve thing. If you remove your EPA stuff you will just end up capping that hose. Still, don't go removing anything without being certain about what you're doing.
 

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I removed my afterburner (EPA) last summer. Damn! I wish I removed it earlier ;) More torque, runs smoother, less heat, noticeable fuel economy. Well, more pollution? I'm not sure about that, because of better mileage per gallon :)
 

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I'd say unless you have to put your bike through an emissions test or inspection there isn't much reason not to remove the EPA stuff. At the very least it cleans up the engine a bit.
 

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the vacuum hose starts at the rear top of the carb, and has 2 functions, #1 to open the plug inside the petcock so that gas can flow to the carb bowl, and #2 to open the valve inside the EPA gold valve so that air can enter thru the 2 nipple inlets at the top of each of the cylinder jugs, that air will go thru the reed valves that are at the top of each cylinder head so that oxygen mixes with the exhaust fumes so that any unburned combustion mixture can combust in the exhaust pipes, The hose for #1 is needed, the one for #2 is not, so when #2 is removed, install a automotive heater hose between the 2 nipple air inlets at the tope of each cylinders, you can plug the inside of the heater hose with something to prevent air passing between the cylinders, I plugged mine in the middle with a metal nut and bolt
 

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the vacuum hose starts at the rear top of the carb, and has 2 functions, #1 to open the plug inside the petcock so that gas can flow to the carb bowl, and #2 to open the valve inside the EPA gold valve so that air can enter thru the 2 nipple inlets at the top of each of the cylinder jugs, that air will go thru the reed valves that are at the top of each cylinder head so that oxygen mixes with the exhaust fumes so that any unburned combustion mixture can combust in the exhaust pipes, The hose for #1 is needed, the one for #2 is not, so when #2 is removed, install a automotive heater hose between the 2 nipple air inlets at the tope of each cylinders, you can plug the inside of the heater hose with something to prevent air passing between the cylinders, I plugged mine in the middle with a metal nut and bolt
I have removed the #2 and installed a automotive hose between the nipple air inlets, but didn't plug the hose in the middle. So air can free circulate between the two tops of cylinders.
What is the differents, plug or not plugged, what is the engine effect in the two cases ?
 

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If you read the Russian Wolf PDF, he says he just put a straight unblocked piece of hose between the two nipples and didn't have any problems. I used two vacuum caps because it keeps that part of the engine just slightly less cluttered. My vacuum caps are starting to crack though and need to be replaced, so if you go that route I'd suggest using vinyl or silicone caps.
 

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you can plug the inside of the heater hose with something to prevent air passing between the cylinders
It's exactly what I did and it seems to be the best solution. If the afterburner gets removed, I totally agree that cylinders should be separated. Actually, as I found out, in this case there is no technical reason for cylinders to be connected any more.
What is the differents, plug or not plugged, what is the engine effect in the two cases ?
First, I just connected them and by long city rides on low rpm's noticed some kind of engine hoarse and power loss thereafter. Going back to hinger speeds and rpm's it was ok again, but anyway, that was not what I was expecting. Since I separated both cylinder with big metal pin inside the pipe, all problems gone forever.
 
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