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Pick your brain- Carb/Hose issue

Old 05-14-2011, 10:00 PM
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Pick your brain- Carb/Hose issue

So I've been searching through the forums for this and have found things that were kind of close to my issue, but not quite. So maybe you guys can try and help me out a bit?

I just finished jetting my carbs and getting them installed on my bike. My buddy and I wanted to test the bike, so we poured gas into the hoses for the carbs, and everything ran fine. We made our idle adjustments and sinced them, everything was good. Then we put the air filter box on there and did it again, and everything was still good. Then we went and tinkered around with some other things, cosmetic work and what not.

Then we decided to put the gas tank back on. Now we did plenty of research and know all about PVLIR and how to avoid it. So we followed the pictures on some forum threads and the manual, and everything was great. But when we fired it up, we were having a lot of issues just getting it to stay running, and after a couple times, it wouldn't fire up at all. so we started playing around with it, thinking that it was flooded, then we played with the choke, and no dice. Well then we went back and checked our hoses to make sure we had done them right, and when we took off the hose to the Rear carb I believe (the hose on the right side when you're sitting on the bike), we noticed it was bone dry. So the front carb is getting gas through the hose, but the rear carb isn't creating a vacuum and having gas go down the hose. But when we poured gas in it and left the other hose hooked up to the bike, it ran fine, just like it did before. There doesn't appear to be any leaks coming out of the hose either.

Anyone got any ideas? Maybe an issue with the clamp on the hose not sealing it to create a vacuum? That's my only guess...
I don't know though
Thanks
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Old 05-14-2011, 11:19 PM
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It's weird that only one hose is wet.

I don't think the fuel hoses create the vacuum on this bike. What happens is the vacuum from the rear cylinder opens the petcock and fuel drains into the carbs- basically it's a valve that allows gravity do do it's think when the engine is on...

That being said, you may have a petcock issue. It may not be operating properly to allow the fuel to go through the lines. Could be the petcock vacuum line is cracked or something too... may want to check that one.

These are all just guesses, but pretty cheap/fast to check. When you just poured gas in the hoses, the carbs were using fuel equally as fast?
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Old 05-15-2011, 07:27 AM
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Originally Posted by 7moore7 View Post
.......you may have a petcock issue. It may not be operating properly to allow the fuel to go through the lines. Could be the petcock vacuum line is cracked or something too... may want to check that one.
+1
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Old 05-16-2011, 02:56 PM
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Originally Posted by 7moore7 View Post
It's weird that only one hose is wet.

I don't think the fuel hoses create the vacuum on this bike. What happens is the vacuum from the rear cylinder opens the petcock and fuel drains into the carbs- basically it's a valve that allows gravity do do it's think when the engine is on...

That being said, you may have a petcock issue. It may not be operating properly to allow the fuel to go through the lines. Could be the petcock vacuum line is cracked or something too... may want to check that one.

These are all just guesses, but pretty cheap/fast to check. When you just poured gas in the hoses, the carbs were using fuel equally as fast?
Thanks, I'm gonna be looking into it today. As far as them using the gas equally, I don't know. We just poured gas into the hoses, so I don't know how much gas one side got compared to the other, but they did run and accelerate just fine with no sputters or carb farts or anything.
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Old 05-18-2011, 12:55 AM
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So...how is the bike? Running ok? What was the issue?

Miguel
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Old 05-18-2011, 11:08 AM
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I just got the bike running last night.

It was unbelievable.

I did my best NOT to hook the hose to the bottom nipple of the petcock, and I didn't. But I sure as HELL didn't have it in the right place. On top of that, I had the fuel switched off. That stupid thing.

I don't even know How I had it running before. But, I went through, it was a 30 second fix. I'd seen so many pictures on here in the last couple days I knew exactly what I did.

Got everything back on, and it turned and fired on the first crank. Adjusted the idle, and now she runs like a beast sitting around 1300 RPMs.

Thanks guys!
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Old 05-19-2011, 08:20 PM
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Originally Posted by AK Ronin View Post
I just got the bike running last night.

It was unbelievable.

I did my best NOT to hook the hose to the bottom nipple of the petcock, and I didn't. But I sure as HELL didn't have it in the right place. On top of that, I had the fuel switched off. That stupid thing.

I don't even know How I had it running before. But, I went through, it was a 30 second fix. I'd seen so many pictures on here in the last couple days I knew exactly what I did.

Got everything back on, and it turned and fired on the first crank. Adjusted the idle, and now she runs like a beast sitting around 1300 RPMs.

Thanks guys!
quoted bc that's funny
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