SuzukiSavage.com - petcock only works on prime

rocky YaBB Newbies Offline I love YaBB 1G - SP1! Posts: 26	petcock only works on prime 11/15/07 at 17:57:22 If I put my petcock on prime my bike runs fine. If I put it on reserve or run it pumps fuel out the vacuum hose and the overflow. Is it bad diaphram?
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Reelthing Serious Thumper Alliance Member Offline Fish or ride that is the question Posts: 5397 Houston,Tx Gender:	Re: petcock only works on prime Reply #1 - 11/15/07 at 19:08:12 overflows do not - the vaccum line sounds like it - and be really careful you can end up with a crankcase full off gasoline - not good - eats the bearings and cam in no time search a bit - quite a lot of postings on the matter
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T Mack 1 - FSO Serious Thumper Alliance Member Offline sold 2001 LS650 for a 1986 XLH1100 Posts: 2919 Emmaus,Pa Gender:	Re: petcock only works on prime Reply #2 - 11/15/07 at 19:17:27 Like Reelthing says, read the posts, but it really sounds like it's bad. Fuel coming out the vacuum hose it a big clue. Note: Check your oil. Probably should change it to be on the safe side.
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barry68v10 Serious Thumper Offline Posts: 955 Maryland Gender:	Re: petcock only works on prime Reply #3 - 11/16/07 at 03:15:41 Some here really like the vacuum actuated petc0ck, but when I started having problems with mine I converted it to manual operation and haven't had a single problem since. There's a post in here on how-to convert it...
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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28651 Tucson Az Gender:	Re: petcock only works on prime Reply #4 - 11/16/07 at 10:11:51 If the diaphram were bad, you would run way rich and stumbly even on prime, because gas would be sucking down the vac line. Running good on prime says that your vac line is leaking air and won't pull enough vacuum to open the diaphram. Replace the vac hose and you should be O.K.
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barry68v10

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Re: petcock only works on prime
Reply #5 - 11/16/07 at 14:20:42

Serowbot wrote on 12/31/69 at 16:00:11:

If the diaphram were bad, you would run way rich and stumbly even on prime, because gas would be sucking down the vac line.
Running good on prime says that your vac line is leaking air and won't pull enough vacuum to open the diaphram.

Replace the vac hose and you should be O.K.

True dat! But the petc0ck conversion deletes those pesky vac lines... Grin

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petc0ck mod, white spacer removed, 150 main jet, 12.5" shocks, 16" turnout muff, oil cooler mod, chain conversion, Tkat brace, external fuel filter, fuel screen removed...

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rocky

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Re: petcock only works on prime
Reply #6 - 11/16/07 at 16:29:25

I replaced the vacuum hose and gas is still running out the 2 tubes that are on the upper part rear of the carb. they run behind the little side panel. I don't have a problem converting petcock to manual but I would like to be doing the correct repair. As soon as I put the petcock on prime it runs great and there is no stumble and perfect idle and running. switched to either run or reserve gas comes out the 2 tubes. help!

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rocky YaBB Newbies Offline I love YaBB 1G - SP1! Posts: 26	Re: petcock only works on prime Reply #7 - 11/16/07 at 19:23:59 I just realized the vent tubes are hanging down well below the carb could that be the problem?
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barry68v10

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Re: petcock only works on prime
Reply #8 - 11/16/07 at 20:13:32

rocky wrote on 12/31/69 at 16:00:11:

I just realized the vent tubes are hanging down well below the carb could that be the problem?

No, I don't think so. My vent tubes hang below the carb, as do the one's on my dirtbike. It's kinda sounding like your float need is worn out, except for the whole bit about PRI petc0ck position seeming to cure all. So I'm gathering there's no gas leaking at all on the PRI position?

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petc0ck mod, white spacer removed, 150 main jet, 12.5" shocks, 16" turnout muff, oil cooler mod, chain conversion, Tkat brace, external fuel filter, fuel screen removed...

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rocky YaBB Newbies Offline I love YaBB 1G - SP1! Posts: 26	Re: petcock only works on prime Reply #9 - 11/17/07 at 04:12:18 there is no gas leaking in the prime position, everything is good and runs fine
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rocky YaBB Newbies Offline I love YaBB 1G - SP1! Posts: 26	Re: petcock only works on prime Reply #10 - 11/17/07 at 08:09:58 I raised the carb vent tubes up to the frame rail and after about 30 secs the vent tube starts to spew gas. As soon as I swith the petcock from run to prime it quits. Does anyone have any suggestions?
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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28651 Tucson Az Gender:	Re: petcock only works on prime Reply #11 - 11/17/07 at 09:17:21 Time to do the petc0ck conversion. Info on how is in the tech section. I did it. It's not to hard. Good luck,
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barry68v10

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Re: petcock only works on prime
Reply #12 - 11/17/07 at 12:15:39

Hmmm, so after all this, we're back to my original post. Cheesy

Quote:

Some here really like the vacuum actuated petc0ck, but when I started having problems with mine I converted it to manual operation and haven't had a single problem since. There's a post in here on how-to convert it...

Also, I would consider removing the internal fuel screen and adding an inline fuel filter...that change added about 30 miles to a tank of gas for me.

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petc0ck mod, white spacer removed, 150 main jet, 12.5" shocks, 16" turnout muff, oil cooler mod, chain conversion, Tkat brace, external fuel filter, fuel screen removed...

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Trippah

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Re: petcock only works on prime
Reply #13 - 11/17/07 at 17:44:13

I don't think this is going as well as it could. If rocky wants to keep the vacumn system in place, then the real question is; why is the fuel leaking out the vent tubes when he is using the vacumn vs the gravity feed position. He has replaced the vacumn lines, it still leaks. Next check, I would think is to open the top half of the carb and see if the diaphram is okay, or if the needlejet whatever is hung up? Yes?

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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28884 L.A. California Gender:	Re: petcock only works on prime Reply #14 - 11/17/07 at 18:05:14 First, (sorry) is the carb hosed correctly? Vacuum to petcork, vents pointed up? check with pictures in clymers, SSM or tech section. If you're overflowing it has to be a needle valve problem. If all else fails, remove carb and clean the he!! out of it. You got some demon in there.
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