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Discussion Starter #1
First post in a long time...

I have a '95 VN750 with 14K miles, and I took off the "Goats Belly" and installed a bypass, removed the reed valves and installed blanks and plugged the lines where needed, installed K&N air filters, and had the carbs re-jetted at the Kawi dealer. This model does NOT have the "Prime" setting on the petcock, just off, on, and res (I got into an argument with the owner of the dealership about it and had to bring it in and show him before he would believe it). I can run it to work in the mornings, when it's nice and cool, with no problems. After it sits in the sun all day, I can get about a mile from work on the way home and both carbs starve out. After messing with it for 5-10 minutes it starts up and there's no more problems the rest of the way home. I thought that it might be the diaphram in the petcock, so I removed the tank and installed a new one. No help. I've checked the vacum line to the petcock and it's sealed tight. Running it in reserve doesn't change anything. It just seems like the "O" ring on that diaphram is sticking when it gets hot outside. I've gone through my second can of Sea Foam, and noticed no change. If the screen on the petcock were plugged then it should do this all of the time...

Is there a petcock made that doesn't use a vacum diaphram that I could install? It was 100 degrees when I left work today (Boulder, CO), and I ended up sitting beside the road for 10 minutes in my leather jacket before I could get it to fire up again. Or could I modify this one to work like the old ones that would feed gas whenever it was turned to on? I hate this vacum setup! :(

I'll not be riding it anymore until I can get this straightened out...

Thanks for any and all help and suggestions.

Buck
 

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HAWK
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There has been people having this problem, check you vent line for your tank.
It is under the cap, if it gets clogged causes a vacume in the tank and wont let fuel flow out.
In the morning the motor is heating the tank and creating pressure, once it is hot from sitting in the sun cant get any hotter, when you ride the wind cools the tank creating a vacume.
Take a straw and try blowing through the line, may also be pintched under the seat.
 

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Discussion Starter #3
Chad, I even opened the tank cap thinking the same thing, and it still took 10 minutes to get it to fire. What you are saying makes a lot of sense, so I just went out and stuck a 60 mL syringe into the vent tube and ran it in and out several times, then did the same with the vent holes in the cap itself, and both were clear. I still think it's the diaphram "O" ring sticking. I can squeeze the vacum line and feel the vacum pulses, so that's not leaking...

Thanks for the idea, though.

Buck
 

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my bike kind of did the same thing when I first got it a couple months ago. although I also had a problem of the idle hanging up and not coming right back down. However I noticed on hot days at the beginning of summer after work the bike would die in about the same spot a half mile from work. I realized every time it did it I didn't let it idle on choke very long before I took off. after letting it idle longer choked I never had the problem. as for the idle problem, my local kaw dealer offered to take the carbs apart for 275 bucks but couldn't gaurantee that was the problem. so after reading this site and talking with Tcat on here I opted for 2 cans of seafoam.. end result, running great for 14 bucks!
 

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Discussion Starter #5
Thanks borto. I haven't had to use the choke at all since winter. At 6:30 in the morning, at about 55 degrees, it fires right up. At 3:30 in the afternoon it's between 85 and 100 lately, and it fires right up. Yet it only seems to quit on me when I leave work in the afternoon. The owners manual even says to not use the choke when it's warm out. I'd like to hear some other thoughts about using the choke, even when it's warm... You might be onto something. Anybody?
 

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HAWK
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Makes sence, try the Choke a little, Have you used Seafoam?
That helps alot with Fuel related problems.
 

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Discussion Starter #7
Thanks Chad. I've used two cans of Sea Foam with no noticable results. I will give it one more try and ride it tomorrow to work and use the choke for a while. I just went out and started it and used the choke a bit. It died when I got the choke up to half closed, restarted it and it died again when it got to half closed again. That's totally different than when I was riding it to work when it was 23 degrees (I use a snowmobile suit and ride as long as there's no ice on the road or snow predicted). I guess I really don't know what to expect using the choke when it's warm. I've always just used it to get started when it's cold.

I'd still like to eliminate all of that vacum stuff at the petcock, though... I'm 59 years old and I've been riding since I was 16. The old style petcocks worked just fine as long as the screens were kept clean. Since all of this trouble, even if the choke trick works, I think I'll always be suspicious of that petcock. That doesn't make for fun riding if you're always wondering about it.
That, and it's kind of embarassing to have your co-workers seeing you pulled over to the side of the road every day trying to get your Vulcan to run...

Thanks for all of the replies folks. I'd welcome any additional ideas, as well. I'm going to get ready for bed and give it another shot in the morning.

Buck
 

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Must be somethin' goin around 'cause my '86 just started doing this yesterday. It happened to me twice after the bike sat in the sun for a few hours in the 95 degree (dry) heat here in Nevada. Let the bike sit for a few minutes and it started up again. Acted just like it was out of gas but had only gone 40 miles since filling up. I run seafoam in it. I tried opening the gas cap, switching to reserve. Nothing would work until the bike sat for 5 or ten minutes. I will try letting it warm up with the choke and see it that helps.
Cheman
 

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I always use the choke on initial start-up - just less time in warm weather. But it does sound more like a vacuum problem - just no fuel getting to the carbs once you've started out. Have you pulled the petcock yet to see what's going on? I rebuilt Orleans' petcock and it was a mess - those diaphragms are pretty cheesy and I could see that being the culprit. It's an easy pull and cleaning job - probably an hour, tops. You might want to get a petcock rebuild kit (new gaskets, etc.) to have on hand, though, since you'll already be in there.
 

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Mine does the exact same thing when it feels like it, usually when I'm in a hurry and don't use the choke. So far I've replaced the vacuum line, cleaned the tank, cleaned the vent in the cap, replaced the ignition switch, maintenance free battery, and new spark plugs. I can start it without using the choke and not have any problems but when it acts up it's a royal pain to get to refire. I think it has something to do with the orbit of the second moon around Jupitor.
 

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Cindy-
Is the petcock rebuild kit a dealer item or is it available as an aftermarket product? I would like to give that a once over. Also, on my bike there is no vent line that runs from under the gas cap to under the seat or to anywhere else. There is a nipple under there and two small holes on the bottom of the lock mechanism but no tube or anything. I have made sure these are clear. I have seen on the parts microfiche that it shows one or two lines(depending on the year) coming off the rear of the tank, mine does not have these either? :confused: thanks
Cheman
 

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Hey, there -It was an aftermarket rebuild kit, but seemed fine by me (and probably cheaper). I'll look for the thread in which I'd posted the link - it didn't cost much. http://stores.ebay.com/Sirius-Consolidated-Inc


There should be a vent host coming off the nipple on the left, back side of the gas tank - it's probably a 3/8ths hose, and needs a clamp. Orleans didn't have one (I'm shocked!), but McKnight does - there's a hole in the frame right about where the exhaust cannister is, and the vent hose threads right through there. It's maybe 12-18 inches long.
 

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Is it just me or does everyone seem to be having problems with there gas tanks lately.

Makes me wonder if the gas quality is going down (even though the proces are sky high). Especially since it is a wide range of years that are having the problem.
 

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Now I am really confused about my tank because it has no nipple at the left rear of the tank:confused: There is a nipple on the plastic cover for the fuel guage sender on the bottom of the tank, (I guess thats in case the gasket there leaks) but no tube coming from it. There are no other nipples or line connectors other than those on the petcock itself. I think mine vents thru the cap itself. Anyone else have a tank like mine???:huddle: BTW the bike ran fine on the way to work, I'll see what happens after sitting in the sun all day.
Cheman
 

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I just looked at the parts diagram at buykawasaki.com and it does show a tank with no nipples/fittings on the rear of the tank. #51002/k/l/m/n and #51003/a, but it does not list these in the parts list, I guess I have one of these tanks.
Cheman
 

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Is it just me or does everyone seem to be having problems with there gas tanks lately.

Makes me wonder if the gas quality is going down (even though the proces are sky high). Especially since it is a wide range of years that are having the problem.
Yes. "They" are adding ethanol to the gas, which attracts more water. I saw a carb the other day when I was at the shop - a fairly new carb - and one inside piece of it had actually rusted itself shut. Whatever we're putting in there isn't good - I don't know how much Seafoam can do to beat the system, but it can't hurt.

Cheman - if you don't have any vent (noun)...then...how does your tank vent (verb)? :confused:
 

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Cindy-I dont know but I guess I am venting(verb) about my tank not having a vent(noun) to vent(verb). Yesterday I vent(accent)to the store.:D and today I vent(accent again) crazy.:doh:
Cheman
 

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Discussion Starter #19
Thanks Cindy. Yeah, I've already pulled the tank and rebuilt the petcock putting in a new diaphram and gaskets. It didn't help a bit.

I rode to work again today. Before I left for the ride home I let it idle with the choke about half way. Any more than that and it would die. I then rode about a mile and a half around the facility where I work to make sure that I was good and warm before I put it on the road home. I didn't have any problems. I stopped for fuel on the way home and put some more SeaFoam in it.

This whole choke business just seems counter-intuitive to me. The only time that I've ever used a choke is on cold mornings when that was the only way to get the motor started. Using it when it's this hot just blows me away...

I'd still like to replace my petcock with a standard, read: NO VACUM GADGETS. If I want the fuel turned off, I'll turn it off myself! I know that it's supposed to provide some level of safety, but I really don't want the nannies messing with my motorcycle.

Does anyone have any ideas where I could find a standard petcock???

Thanks,
Buck
 

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Buck,

if you're in Boulder, take it to Bob'n'Rolf's place... those two are wizzards for ancient bikes, not like stuck-up Colorado Powersports people, and not as naive as Rocky mountain Kawasaki guys in Longmont :)

BTW, I'm in Boulder too. We should get together sometime :)
 
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