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Discussion Starter #1
On the way home tonight from dinner, the bike started acting like it was running out of gas. I was getting lowish, so I switched to reserve. Well, it proceeded to keep running rough and I pulled in the clutch to pull into the turning lane and it died. I tried to crank it and it backfired but didn't start up. Then it started having trouble trying to turn over even. So I stopped and called a friend with a trailer.

So I waited a while (and peed in the ditch if it matters :)) and decided I would try it again. To my surprise it cranked. I put it in neutral and it even idled fine. The OL got back on and we rode it back home.

Now...could it be the battery that caused that? It is a wet cell battery that the dealer put in when I bought the bike over a year ago. Could it have gotten too hot and caused the bike to die and then when it cooled off, worked fine again?

It just worries me that it acted like it was out of gas, then backfired a few times trying to start, then acted like it was dead, only to end up starting again a short while later.
 

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Deviate, FWIW I went to buy mine. Battery was so far gone, no lights came on w/key. Jumped of the pickup for 15min B4 it would crank. Would not hit, so we used some starting fluid. Monster backfire. After more letting it charge it ran, but only w/jumpers connected.

Peace of mind is as easy as having the battery load tested.

Starts instantly, runs good since the new AGM battery 45 min after I bought the bike.
 

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Chasin' the blacktop
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Ahhh, I probably know your problem, delt with it twice myself when switching to reserve a little too late. Assuming that you've got the problem I had the little ball which allows fuel past when vacuum is applied (from the vacuum line from the front cylinder) is sticking. You can feel the little ball when sucking or blowing on the vacum line intake with the petcock removed.

When running the bike has enough vacuum to move the little sticky ball and diaphragm in the petcock but when the engine is turning slowly from the started there isn't enough vacuum to open the flow of gas. After a while of waiting a bit of fuel slips past the petcock, enough to start the engine creating more vacuum allowing even more fuel to flow.

Until I shot carb cleaner past the detached petcock cleaning the little gummy ball (cleaning gas film off it) I found that by detaching the vacuum line from the front carb and sucking on it to get fuel to flow got me running much faster than sitting around for 45 minutes to let the fuel seep by it).
With the petcock removed and sucking and blowing by mouth I could feel the little ball unstick and move inside the petcock. Even after some carb cleaner I never got the ball to move super freely but it now works much better with little problem after running out of fuel and needing reserve fuel.

Bottom line, first assure that there is no vacuum leak in the line going to the petcock. Then remove the petcock and blow carb cleaner through the vacuum inlet. Rebuilding the petcock doesn't hurt either. Like I had you probably have a “sticky” one way ball valve in the petcock and a petcock vacuum diaphragm that lets a little fuel leak trough.
 

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Dr. Vulcanstein
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Have you relocated the r&r? It's possible that got hot, and when it cooled it fired back up.
 

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Just a regular guy
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That happened to me once about 2 months ago... I was thinking it was poogs... it hasn't happened since so I don't know.
 

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Discussion Starter #6
Thanks guys...good things for me to check today. I'm pretty sure it's not POOGS because just last weekend I removed and cleaned everything on the gas cap and vent tube. I also hope it's not the petcock because I just replaced that with a new one a couple of months ago when I had to pull the carbs to clean them and did the ear shave. I did relocate my R/R to over by the passenger peg.

The only change I have made recently is to remove the goat's belly and put the stock mufflers on with some flex pipe. It has been running fine since I did that though. This just kind of came out of nowhere on me.

I reckon I will pull the battery and get it tested for peace of mind and go from there.
 

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My bike did the same thing and it was practically new. However I opened the gas cap and the bike started up. I would not totally rule out POOGS yet. If it starts happening again shut the bike off as soon as possible, the sooner better. Open the gas cap and see if the bike will start.
You've been on this site awhile and probably already know this. Good luck.
 

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Linkmeister Supreme
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I did not know about a ball valve in the vacuum circuit on the petcock.
That may explain why my reserve function does not work when I need it. :(

However, I am not convinced the following statement is 100% accurate:
When running the bike has enough vacuum to move the little sticky ball and diaphragm in the petcock but when the engine is turning slowly from the starte(r) there isn't enough vacuum to open the flow of gas.
I have stored my bike over the winter a couple of times with empty carb bowls after turning the petcock to the OFF position and running the engine until it stalls. In the spring when the fuel valve is turned back to the ON position, and the starter is actuated, my bike will start after about 30 seconds. That indicates to me that enough vacuum is created to operate the vacuum valve to allow fuel to flow and fill the carb bowls.

The reserve function on my scoot seems not to have functioned properly since I bought it 5 years ago, but I had not needed to use it until last year when I ran out of fuel on the way home from work. I was travelling along at 50 mph on a paved country road with very light traffic when I heard the engine sputter a bit and begin to lose power. I immediately reached down, turned the petcock lever forward to REServe and coasted for a mile with the engine still chugging and coasting, waiting for power to return.

Finally slowed to the point where I had to pull off. Cranking the engine over a couple of times for 15 or 20 seconds brought no joy either so I quit before draining the battery too. Called someone to bring me a gallon of gas and it fired right up. The bike seems to run fine in the reserve position when the tank has any gas it as long as I switch to reserve before the engine sputters indicating that I NEED to switch over. Not very helpful to have reserve gas if I cannot access it. :(

Pulled the tank off last week to check petcock. All seems well. Reserve position allowed me to drain 2 liters (1/2 US gallon)of fuel through either front or rear nipple when applying vacuum by mouth through another hose to center nipple on fuel valve. The gas drained was perfectly clear with no dirt, rust, water or other visible contaminants.

Pulled the fuel gauge sending unit off to check operation and condition too while it was conveniently available. Cleaned and painted bottom of tank in some areas around both petcock and sending unit base where surface rust was evident. Bottom of tank seemed not to have been well painted at factory. Suggest others be prepared to paint it too, if/when you take tank off the scoot. :) I thought it best to mask off or otherwise cover area directly covered by base of petcock and gauge sending unit so O-rings are not sealing off gasoline against a painted surface . I cut gasket like pieces out of cardboard cereal boxes, punched holes and used the bolts to hold them in place while I sprayed the paint.

I thought the reserve would work properly now, but when I tried to switch from coming up the river valley hill Thursday afternoon it would not run, nor start up until I poured the gallon of gas I was carrying into the tank. I am determined to get the reserve function to work properly for me this season so I can trust it and not have to carry a gallon of gas all the time.
 

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Chasin' the blacktop
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Next time you have the petcock off the tank use your mouth to suck and blow in the petcock's vacum inlet. You can feel the "little ball" (or maybe a tiny gate of some sort) click back and forth. I had tried to unscrew the brass vacum inlet but it must be glued or something. By spraying carb cleaner in the vacum inlet several times the "little ball" got much easier to get to move when sucking and blowing on the inlet. Before cleaning it felt like it was always stuck in whatever position I had blown or sucked it into requiring a lot of pressure to get it to move.
 

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Next time you have the petcock off the tank use your mouth to suck and blow in the petcock's vacum inlet. You can feel the "little ball" (or maybe a tiny gate of some sort) click back and forth. I had tried to unscrew the brass vacum inlet but it must be glued or something. By spraying carb cleaner in the vacum inlet several times the "little ball" got much easier to get to move when sucking and blowing on the inlet. Before cleaning it felt like it was always stuck in whatever position I had blown or sucked it into requiring a lot of pressure to get it to move.
The petcock diaphragm will have, for lack of a better word, a puck in the middle of it on the opposite side from the hose. This is what shuts the gas off. May or may no have an o ring. As the diaphragm seats/unseats is probably what you are contemplating. I was thinking about adding a check valve to mine until a member here pointed to the obvious danger.
 

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My bike backfired a lot trying to start it on a weak battery with a jump. With the new AGM battery it starts so quick, it's like turning on an electric motor.
 

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Discussion Starter #15
Well I'm not saying that the issue I had the other night was the battery, but I just took my old battery up to Advance Auto and had it tested. It was only showing 160 CCA and less than 12 volts saying it need a charge. So I went ahead an bought an AGM battery. It has been on my list of things to do anyway and buying it online I was able to use a coupon to get $25 off. So after core and everything it came right about $62. Worth it for the peace of mind I have knowing I've got a good strong battery now.

Now I'll just see if anything like what happened Friday night happens again.

And it was the backfiring that really made me question if my issue was the battery. Backfiring and and just seeming to drag a little while trying to start.
 

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Those AGMs just seem hotter, I just posted in another thread.. The AGM started my bike just fine with only 11.5-11.75v showing. With a full charge, it's held about 12.80v for weeks ... since I pulled the engine off.
 
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