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Fuel problem?

6K views 41 replies 6 participants last post by  knightrider 
#1 ·
Hello all. I bought my 1998 800vn in June I would say, it had sat at my friends dealership for about 8 months before he got tired of looking at it and we agreed on a price. I had to install a new battery, but it started right up and I drove it probably 2000 miles before I parked it a couple months ago to go out of town. I came back, it was dead. I recharged the battery this morning and was on my merry way. I'd say I rode a good 30 miles or so, came back home patted myself on the back and did a few Tim Taylor grunts. My GF came home, we decided to go out again. Everything went well, for about 15 miles. All the sudden, I noticed at a red light the bike was dying. I applied the gas a little more firmly, turned around to go home. Next red, same thing. As I was approaching the following Red, it was sputtering and felt like its moments were numbered, so I pulled into a gas station, got almost to a good parking spot, and POOF, gone. Frustrated, I was. I had put gas in it earlier when i reconnected the battery about a mile out, but didn't fill it to the top as I know this is a problem sometimes. I checked the gas at the station I was now stranded and looking foolish at, plenty of gas. Tried to start it, and all it did was click quite a few times and wound to a gasping death. Still had lights, but no turn over. I looked around and realized I wasn't looking very cool at this point, so in my shame I pushed the bike to the side of the gas station for less people to mock. Still dead, I called a friend up who was polite enough to bring me a jump box. While sitting there I noticed to the (if sitting on the bike) left side there was a small pool of fuel about a half dollar sized. My friend came, The motor roared back into life and off I was to drop it off to my friends garage for tomorrow. I'd say his garage is about a mile from where I spent quality time with the strangers at the station, it rode fine even stopped at the red, and continued on. I pulled up to the shop, eyed a decent parking spot and pointed the front wheel in that general direction. I almost made it too. I got about 10 feet from it before the bike died once again. Now, I have 2 other bikes, so I know a thing or two, but not everything. Also those bikes are fuel injected, I'm not much of a carb guy. I did read a few forums sitting out there in the moonlight via my smart phone, talking about pops and swooshes when opening the fuel tank, of which I got neither.I realize my battery is probably toast but I can't imagine it would cause such a slow death and fuel to leak out. If you have any advice, it would be very appreciated. I really enjoy this bike, and look forward to many many more miles on it.
 
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#2 · (Edited)
Don't know about other Vulcan models but the fuel pooling issue happens with the VN800 as I've read from all of my research. Along with other things that is. My first question would be is it a California model and if so are there any mods to the EPA system hoses or the tank?

Have you checked the tank or fuel cap vents to ensure they are not clogged? Have you checked to see if the float and carb fuel level or diaphragm are working correctly? Did you check to see if your carb manifold is seated or sealed properly, cracked or loose? Did you clean out the old fuel when you got your bike by using the drain on the bottom of the carb because sometimes water and debris accumulate in there so make sure the carb is well cleaned and working well before proceeding.

I can't find the thread right now about the fuel pooling issue(s) you are experiencing but one of the senior members should be stopping by anytime soon to point you to the right thread for that one.
 
#3 ·
You have two problems, bad battery, bad petcock (most likely)

Bad petcocks are very common on the 800, I'm assuming the fuel is running out the carb, this is generally the case on a bad petcock. From what most have experienced on here it is not worth the effort to get the rebuild kit, some have managed to get lucky and it worked, but many others still had problems only to buy a brand new one and have the problem solved. So the consensus is to buy a new one outright and be done with it. If that doesn't solve it then you will probably end up needing a new needle valve in the carb. Try moving the petcock to different positions to see if the fuel stops leaking, on run or res there should be no fuel leak, if it is on pri and there is a leak this would point towards the needle but you should not be running in the pri position normally anyway.
 
#4 ·
Hmm. Yes I see how the petcock would be a problem. A quick glance at JC whitney and I notice They have a K&L petcock valve for 32.30, a Bikers choice petcock for 13.05, and of course a Pingel petcock for 100.53. Any one have any experience with any of these? is higher cost always better?
 
#5 · (Edited)
Hmm. Yes I see how the petcock would be a problem. A quick glance at JC whitney and I notice They have a K&L petcock valve for 32.30, a Bikers choice petcock for 13.05, and of course a Pingel petcock for 100.53. Any one have any experience with any of these? is higher cost always better?

Now, I have 2 other bikes, so I know a thing or two, but not everything. Also those bikes are fuel injected, I'm not much of a carb guy. I did read a few forums sitting out there in the moonlight via my smart phone, talking about pops and swooshes when opening the fuel tank, of which I got neither.I realize my battery is probably toast but I can't imagine it would cause such a slow death and fuel to leak out.
I didn't mention the tap because you said you have 2 other bikes and know a thing or two. There are at least several reasons why this type of bike can leak and sputter so I just mentioned a few non-obvious ones to try and help you. Wish you success but post back when you get it repaired so that others can learn off your experiences. Only reason I say this is because many never post back once it is repaired.
 
#6 ·
Well it turns out the battery was dead, I returned it for warranty and got a new one. Bike runs great again, at least on that part. I haven't Looked very hard, but I see the gas is leaking on the right hand side, and making its way around to drip on the left (when sitting on the bike) I opened up the air cleaner to try to see anything obvious, and the filter is drenched on the bottom side. I could also see that gas was on the right side forward cylinder body, but not on the chrome. I looked at the pri/res/on switch on the LH side and noticed it was remarkably new looking, and no gas is around it anywhere. I intend to bring it home later today to further investigate, etc. Again I'm not much of a carb guy, the only one I've ever had any success working on was a gas powered RC car, the other bikes are FI. On a different note, My back brake is locking up. I looked all around for the problem, and noticed that when I depress the brake foot pad, on the back the metal arm attached to the hub and bar does not go back to its original place once released. I can manually pull it back with a little effort, but really thats about it. I saw the brake pad indicator which was mid way within range, and doused the outside as best I could with brake cleaner, then again with a spray lubricant (not wd40, think it was a graphite spray lube). No luck really. it still sticks.
 
#7 ·
It isn't a cali model, It has always been in KS. I will pull it all apart when I get it home later, Just asking all advice on what to look for. I did clean out the old fuel when I bought the bike, I changed out all the fluids just to be on the safe side. I will check all the things you mentioned before, comanche. The shop was too full today to do much there. Bamadrive, I have noticed when I put it in the PRI position before, it did indeed leak. I never run it on that of course. If we determine the petcock and needle are bad, where is the best place to get such things? I should also mention I did a visual inspection of all the hoses that weren't hidden, and didn't see any signs of wetness or damage to any, but I haven't pulled that side apart much so that still could be the case.
 
#8 ·
You can test the petcock by removing the fuel hose and see if it will drain. Obviously catch it in a safe container and don't light any birthday candles for extra light.

On the run and reserve positions it should not have any gas flow. On prime it should flow freely. You can test the small vacuum line also, fuel will flow in the run or reserve postions when a vacuum is applied to the small hose, it doesn't take much you can do it with your mouth if you don't have a pump.

These will indicate if the petcock is definitely bad. Several have replaced theirs with aftermarket valves with no issues.

If the valve is good then you will probably need a new needle and they are not cheap. You could probably find a whole used carb for about the same price as a needle. But no sense going there until you know if your valve is good or not.

I'm sure there are others checking this thread, feel free to chime in if I'm steering him wrong or if you have another idea. I still have the oem valve on my 99 but I've read about the issue enough times here to know my days are numbered also.

About the back brake, it is cable operated, check by the pedal you'll see where the cable enters a housing and goes underneath. More than likely I'm guessing the cable is frayed just inside the housing and is now bound up. If you can't see any obvious damage to the cable try to see if you can get some kind of lube down into it, it may just be rusty and you may be able to work it loose. Where the cable exits the housing it is attached to a long rod to work the brake. I'm guessing that is the rod you mentioned. I recently had to replace mine it was 39.00 shipped. I forget where I got bought it on the internet but that was the best price I found.
 
#10 ·
That image is a triple carb set up. Try looking on bikebandit.com or procaliber.com. both are good places for oem parts, but procaliber is def cheaper.

The new oem petcock is not that expensive, but obviously test yours first. If it leaks fuel when not running then you most likely have a bad petcock, or you left it on prime. If its leaking while running (which mine did when I first got it) I would recommend tearing it down and giving it a good cleaning. Also check the float and the float height.

These bikes are getting old and are often neglected, but its not too difficult to them running well again.

Oh and post some pics in pics thread.

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#11 ·
http://www.bikebandit.com/houseofmotorcycles/1999-kawasaki-vulcan-800-vn800a/o/m149601#sch74613

I had just looked it up when Phil posted.

There are several threads here on the forums on this same problem and most end up with a bad petcock.

If you have to go into the carb one of the carb wizzards can take over and get you going.

I didn't realize the oem needle wasn't a higher price, the dyna jets and cobra needles run in the 75 dollar range and I figured the oem would be much higher. But no sense putting the cart before the horse yet til you have ruled out the petcock valve.
 
#12 ·
Well friends, good news. I'm writing this for the second time as my computer decided it apparently didn't like my first comments because it erased them.

I checked the petcock, all was well with it, worked just like it should. After a good Google search I discovered that sometimes the float sticks on these. I took the air breather assembly off and could clearly see gas flow exiting from the bottom forward area of the carb. From there I took some decent carb cleaner and gave it a few good squirts. From there I worked the throttle a little, took a piece of wood and small rubber mallet and tapped gently but firmly all around the showing carb, of course not hitting the actual opening. Then I sprayed again, working the throttle again to move anything around that might be in the way. Afterwards, I cleaned up the carb with a clean rag, cleaned my forward cylinder housing off and dried it. I spent about 5 minutes bolting down the back of the tank (was easier to remove the air cleaner assy this way), bolted down the seat and really was just goofing off a little. I came back to it, completely dry. I read quite a few forums where this worked with great success, and it worked for me.

My back brake is still sticking. I removed the arm from the rod/cable assy and it moves freely when not attached. My question is there any way to lube those? I have seen a tool online that you attach to the cable and it mystically lubes the inside between the rubber and cable. Does anyone have experience with this? Or do I resign myself to buying a new assy?

On a different note. On the air box, back side there is a plastic clip attached at the 5 o'clock position slightly under and forward of the back bend of the exhaust. It holds some kind of cable that I really couldn't tell where goes. Anyhow, I kinda sorta broke it. I feel it was dried out kind of like on an 80's car wiring harness where you bend the clip to remove the connector and it just breaks. My question is of course how bad is this? I will be looking for a new box so it doesn't mess anything up, but is it ok for now? Remember I just bought this bike recently so I don't have a service manual just yet for it. Bare with me.

I really appreciate all your help guys. I tried to honor the forum by posting my results as best as I could. Thank you.
 
#13 ·
Honestly, if this solves your carb issues for any real length of time I will be very surprised.

As for the airbox, could you take a pic? Are you talking about where the idle adjuster attaches to the airbox? Or where the hoses attach to the back?

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#14 ·
Hey Phil, I agree but at least I know what it most likely it is. All else fails I'll just rebuild the lil guy. Here is a pic of it, dirty fingers and all. I'm thinking it probably just held it in place really. It's not to where it can fall out, its not broken that bad, you can just wiggle it a little with your fingers.
 

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#22 · (Edited)
Do you mean at the bottom where the drain is that holds the Idle Adjusting screw? I may have an extra complete housing to sell you that is in excellent condition if you need one. Let me know but if it is this and if you don't mind it being broken it really doesn't hurt anything and nobody will see it anyway. However, if it is the drain nipple then it can leak fuel from the air filter breather assembly and spill onto the bottom right side of your motor underneath the carb and that's not a good thing either. There is usually a small separator bottle drain type thing that goes on the end of the drain tube and I've even seen people put small inline fuel filters on the end of the drain line instead but to each his own.

If you want to repair it you could just use some plastic JB Weld. As for the Idle Adjustment Screw just hanging there it won't hurt anything if those two small prongs that hold it in place broke off because you can still reach it to adjust it. Nobody will know it is broken except you.

Just let me know if you want a new setup for the breather and airbox assembly. See, I told you to clean that carb really good since you already knew your battery was bad! Glad you got things squared away in short order. I might even have a spare OEM Manual to sell if you need one. I'll have to look for that too if you want it.

Bama, Russian Wolf is a good read. I especially like his use of referring to himself in the Third Person! I, The Russian Wolf! Haha!
 
#16 ·
Your finger is on the idle adjuster. It can just hang there. It shouldn't cause any issues.

Since its about winter, I would plan on just pulling the carb at somepoint and really giving it a go. Pull all the jets and clean out all the passages with carb cleaner and compressed air. I would dip all the parts you can.

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#18 ·
It's actually quite easy. I would recommend doing it yourself or at least with him. You will quickly become a "carb" guy. I am not the most mechanically inclined, but I learned quite quickly while rebuilding older CV carbs on my first bike, an old Suzuki GS twin.

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#19 ·
Yea I planned to help or do it myself with his supervision. I mostly refuse to take anything of mine to the shop if I can get away from it. I've been into bikes for about 5 years and have had several, but all I've ever had was FI. Like I said, the only success I've ever had with a carb was an RC gas powered car once, and I think that was a fluke..
 
#20 ·
Luckily, the carb in the 800 is pretty well documented as its almost the same, only slightly smaller, than what has been on Harleys. I recommend doing some web searching for CV40, what's on the Harley, and CVK36, which is on the 800.

The key to working on them is just taking your time, document what you do, use platic bags or cups labeled to where the parts came from and lastly, don't force anything.


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#21 ·
#23 ·
The cable lube tool is a great gadget! One disconeects the cable, place the cable lube gaget over the end of the cable sleeve with the wire cable sticking through it and tightened it down. Using a can of cable lube, stick the plastic tube into the provided gaget fitting and spray away. The gaget seals around the cable sleeve and the wire cable so when you spray the lube in it is forced down the sleeve around the wire. It really works great. I spray mine until whatever is coming out the other end is clean and then place a rag under the end for a bit to allow any/all excess to drain out. Now you know the cable is lubed for it's entire length. I think mine was around $10 (US) and the lube another $6-8. One can has lasted me for years, on two bikes, both with cable clutches. So 4 throttle cables, 2 clutch cables, 1 rear brake cable, all done 2X per year. Once before winter storage and again mid summer during a regular service routine.
 
#25 ·
An update: Turns out they were correct in saying that fix probably wouldnt last long. When working on it today I noticed gas still leaking, just a much smaller amount. I pulled the carb apart and sprayed the floats and have the whole thing a good cleansing. I'll update again if this doesn't fix it but so far so good.
 
#26 ·
If it persists I would remove the carb from the bike and give it a good tear down and clean it well.

Did you remove the jets and give every small passage way a good cleaning? I definitely recommend liberal amounts of carb cleaner followed by blasts of compressed air. The cans of the compressed air work well for this. I would also recommend getting carb dip like Berrymans and dipping all the metal parts.

It's a pain to do but it will most likely solve many issues. Really anyone buying a used 800 that is older or has a bunch of miles should go ahead a do a thorough cleaning/rebuild. Between that and a new OEM petcock I have a feeling that 90% of peoples issues with their 800's would be solved.

That and giving the chain a good kersosene cleaning and lube. :)

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#28 · (Edited)
KnightRider, any reputable well-stocked retailer should have what you need. Just give them your carb info and they will ask if it's stock or rejetted to whatever it is. Call your local Kawasaki dealer for pricing that you can then use those part numbers to shop around on the internet for the best pricing. Look up the OEM numbers here:

http://partsfinder.onlinemicrofiche.com/cycleparts/showmodel.asp?make=kawasakimc

If your carb has been rejetted then you'll have to know what your parts are so you can find what you're looking for. I rebuild carbs so if you don't have anyone to do that you can mail it to me via USPS and I'll mail it back to you when I'm done. You just pay for parts, shipping and labor but I can get it done (depending on not waiting for parts) within one day's turnaround.
 
#30 ·
Unfortunately no kits. You most likely need a needle which comes with the float can't get them separately and it's a dealer part.

Harley uses a 40mm Keihin CV but the needle is different. The accelerator pump diaphragm will work and it's much cheaper than the Kawai one if you need one.
 
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