MasonHart Posted July 22, 2010 Share Posted July 22, 2010 I do not think there is any vacuum being created on the left side because with all the lines hooked up and with the bike running fuel will not flow on the left side. I can see both side because there is a clear filter on each side. If i take the line off on the petcock side of the filter fuel will run out of the tank no problem. But when the bike is on and running with everything hooked up there is no fuel flowing on that side. The other side is perfect. Is this an issue with the carb not producing vacuum? Or something weird with the petcock? Or possibly a problem with another part? Link to comment Share on other sites More sharing options...
bznchris Posted July 22, 2010 Share Posted July 22, 2010 The carb doesn't produce vacuum. The cylinder does, so yes, the petcock probably needs to be rebuilt. Or better yet, replace it with an on/off/reserve (non vacuum) petcock. These vacuum petcocks are notorious for failing...mine did. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 22, 2010 Moderator Share Posted July 22, 2010 you can test the petcock sometimes just by sucking on the vac line that goes to the manifold and watching for fuel flow Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 22, 2010 Moderator Share Posted July 22, 2010 you can test the petcock sometimes just by sucking on the vac line that goes to the manifold and watching for fuel flow yea, give it a blow job Link to comment Share on other sites More sharing options...
MasonHart Posted July 22, 2010 Author Share Posted July 22, 2010 Could it be a problem with another part of the bike? Because when i connect the line that comes off the petcock gas will pour out just fine but it doesn't ever make it to the carb. It wont even fill up the inline filter. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 22, 2010 Moderator Share Posted July 22, 2010 so if you disconnect the inline filter gas flows good, if you re-connect it flow stops Inline filter blocked? sounds like it Link to comment Share on other sites More sharing options...
MasonHart Posted July 22, 2010 Author Share Posted July 22, 2010 See thats what i thought too but you can see through the filter and the bronze stone is clean. I will clean it out but it doesn't like it needs it. Link to comment Share on other sites More sharing options...
HoughMade Posted July 22, 2010 Share Posted July 22, 2010 My question would whether it runs well. On my bike, at times the fuel filter will get low when I am riding, but there is always gas flowing through it. I say if it runs fine, don't worry about it. Link to comment Share on other sites More sharing options...
MasonHart Posted July 22, 2010 Author Share Posted July 22, 2010 It isn't starting now that i found this problem. I can hit the start button and it starts cranking but it wont start. Yesterday it was starting only if i hit the start button and held the throttle open some. Then it would run but not great. Only on the left cylinder i am sure. And it wouldn't idle all the time, if i let go of the throttle it would slowly decrease in rpm's then die. If it did idle it was vibrated a lot and if i hit the throttle it would very slowly decrease in rpm's back down to idle. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 22, 2010 Moderator Share Posted July 22, 2010 It isn't starting now that i found this problem. I can hit the start button and it starts cranking but it wont start. Yesterday it was starting only if i hit the start button and held the throttle open some. Then it would run but not great. Only on the left cylinder i am sure. And it wouldn't idle all the time, if i let go of the throttle it would slowly decrease in rpm's then die. If it did idle it was vibrated a lot and if i hit the throttle it would very slowly decrease in rpm's back down to idle. sounds like its 'running on one', to find out which side is easy, the exhaust is hot on just one side DONT BURN YOURSELF CHECKING ! Link to comment Share on other sites More sharing options...
MasonHart Posted July 22, 2010 Author Share Posted July 22, 2010 Well i would test that BUT, it wont start no. I think it is flooding because the PO did something with the petcocks and just told me to keep it on prime all the time. But when i was emptying the tank i was getting flow in all positions. But then it would just be acting as a manual petcock. So it should should still give gas to the carb, right? One would think so., But it doesnt have enough force to get it to the carb. The gas stops flowing before the carb. Link to comment Share on other sites More sharing options...
bznchris Posted July 23, 2010 Share Posted July 23, 2010 If you're getting flow but it's not getting to the carb, it must be your filter. Pull it out and see if it will fill the carb. If it doesn't, put it on prime and see if it is vacuum causing the problem. Link to comment Share on other sites More sharing options...
HoughMade Posted July 23, 2010 Share Posted July 23, 2010 Check your float. if the gas doesn't have anywhere to go, it won't even clear an air bubble in the line. Link to comment Share on other sites More sharing options...
MasonHart Posted July 23, 2010 Author Share Posted July 23, 2010 Well its not the filter because i took it out and cleaned it and the problem is still there. The other side is fine with the same exact filter in the same place, except that line is direct to the carb, on the right side it has to go uphill to get to the carb. And the PO said that he did something to the petcocks so i should leave them on prime all the time. So it is acting as a manual petcock now correct? Since prime just lets fuel flow without vacuum. I am guessing that it needs that vacuum to get pushed uphill right? Link to comment Share on other sites More sharing options...
HoughMade Posted July 23, 2010 Share Posted July 23, 2010 No, as long as the tank is above the carb, fuel should flow by gravity. Sounds like your float is not letting fuel in the bowl. Link to comment Share on other sites More sharing options...
MasonHart Posted July 23, 2010 Author Share Posted July 23, 2010 yea i took the carbs off and checked the float bowl. It is dirty and stuff so i will need to clean it. But i need diagrams to know what is going on in there Link to comment Share on other sites More sharing options...
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