Engine cut out in traffic

[AussieValk]

Hopefully someone here can help with this one.

I've had the engine cut out, as if it's run out of fuel, today after sitting in stop/start traffic for ten minutes or so. I was low on fuel, but not on reserve, and it has happened before (in traffic) with about 1/3 of a tank left. It seems that the bike gets warm and the fan cuts in which is normal, then it begins to cough and splutter. If I catch it in time and give it a few revs sometimes thats enough to get it running again. But today it died and it was hard to get started again. Tried it on reserve but no luck. When I got it running using the choke and reserve, it sounded like it was running on five cylinders. I jumped on it and a little way down the road it fired right up and I switched fuel back to normal and got to the service station to fuel up.

I've had the petcock off and put the kit through it, changed the filter (both in tank and one in-line), the vent hose is good with no kinks or blockages and I don't think it is the vac lines, or is it?

It seems fuel related as in some junk in the carbs, but it's strange that it only happens as described above, and I'm sure it's not water in the fuel. Could it be spark related? I'm happy to give more of a description if anyone can help.

TIA

[R J]

Try removing that in-line filter you added.    I mean totally remove & put it back like it was,

I tried to add an in-line filter in mine about 98 or so.    It kept acting like it was starving for fuel and cutting out cylinders,    Since that was the last modification I had made at the time, I took it out and only had 1 misfire since.   That was when I fried the starter relay connector,,

Let us know the out come.

[Robert]

Have you checked the alternator and battery? You may still have enough juice in the battery to kick it over but instead of say 10 volts at starting you may only have 8. Also at idle the alternator doesn't really put out enough to keep the battery up especially with the fan running. Sounds like the alternator is ok but the battery may not be. The only real way to check is with a load tester for the battery and alternator not with a volt meter. Most auto parts stores now have the ability to check batteries it may not be the best but lacking a load tester it may be the only way to check without replacing the battery.

[Grandpot]

Aussie:

RJ is exactly right about the in-line filter.  Get rid of it.

I had the same thing happen to me after I installed an in-line filter.  As soon as I removed it, the problem went away.

When I removed the filter, I blew into it and could feel some resistance.  Then I blew harder (no jokes please) and it cleared up.  I took the filter apart and it was clean.  I think the surface tension of the gasoline is just enough to stop the flow in a gravity fed system like ours.  This type of filter works on a car because the fuel pump is forcing the gas through at about 5-7 PSI.  The reason the bike started working again when you went to reserve is the additional head pressure caused by the reserve intake being lower than the normal intake. 

[Sharkey]

Try removing that in-line filter you added.    I mean totally remove & put it back like it was,

I tried to add an in-line filter in mine about 98 or so.    It kept acting like it was starving for fuel and cutting out cylinders,    Since that was the last modification I had made at the time, I took it out and only had 1 misfire since.   That was when I fried the starter relay connector,,

Let us know the out come.

+1 What Rj said

Also make sure your fuel line is fairly straight. I put a extra long line on to make pulling the tank easier, but it would make a s shape verticly and trap air in the lines, it the acted as your does.

[DFragn]

If you recently added a [smaller G3606 type] fuel filter I would agree with others. Remove it or change it out. Removal first then some near home ride time to quantify its removal. If it seems that was your problem and you still prefer a filter go to the larger G2.

I used the larger G2 [2" diameter] first and because it's clear I could see that the fuel level in it barely leveled above the outlet tube. I replaced it while doing general maintenance because the inbound nipple warped from heat [probably a non issue] with the smaller metal [1.5" diameter] G3606 to save room. I had immediate flow issues and stalling. I removed it and starvation & stalling ceased. My impression is the smaller unit moves too little fuel.
BTW I inspected thoroughly and my problem was not due to kinked or pinched lines. It was definitely the smaller filter. Kingbee had the same issues using the smaller G3606 filter.

I now run without a filter, but when I put one back in it will be the G2 and/or a fuel cut-off valve.

I suspect the smaller G3606 may work while only feeding 3 carbs if they're installed after the fuel line "T". If there's room, I haven't tried that.

[AussieValk]

Try removing that in-line filter you added.    I mean totally remove & put it back like it was,

I tried to add an in-line filter in mine about 98 or so.    It kept acting like it was starving for fuel and cutting out cylinders,    Since that was the last modification I had made at the time, I took it out and only had 1 misfire since.   That was when I fried the starter relay connector,,

Let us know the out come.

I've run successfully with the filter in the past. Originally it was smaller and did cause a starvation problem particularly under acceleration. The one I have now is a larger car filter, about 2" diameter and site vertically just near the petcock. I might try removing it totally as you suggest and see what happens. Thanks for the feedback.

[AussieValk]

Have you checked the alternator and battery? You may still have enough juice in the battery to kick it over but instead of say 10 volts at starting you may only have 8. Also at idle the alternator doesn't really put out enough to keep the battery up especially with the fan running. Sounds like the alternator is ok but the battery may not be. The only real way to check is with a load tester for the battery and alternator not with a volt meter. Most auto parts stores now have the ability to check batteries it may not be the best but lacking a load tester it may be the only way to check without replacing the battery.

I have a Goldwing voltmeter on the bike and it shows as having plenty of juice at idle and then charging over 12V under revs. Battery is also good and not very old. I was wondering if it could be a plug playing up under the extra heat generated whilst sitting in hot traffic. I'll pull them out and check. Cheers.

[AussieValk]

Aussie:

RJ is exactly right about the in-line filter.  Get rid of it.

I had the same thing happen to me after I installed an in-line filter.  As soon as I removed it, the problem went away.

When I removed the filter, I blew into it and could feel some resistance.  Then I blew harder (no jokes please) and it cleared up.  I took the filter apart and it was clean.  I think the surface tension of the gasoline is just enough to stop the flow in a gravity fed system like ours.  This type of filter works on a car because the fuel pump is forcing the gas through at about 5-7 PSI.  The reason the bike started working again when you went to reserve is the additional head pressure caused by the reserve intake being lower than the normal intake.  

I like the in-line filter because of additional hydrolock protection, even though the petcock has been rebuilt. If it has to go to get rid of the problem though, it will. It does feel like a vacuum problem when it happens, and switching to reserve has no effect. The bike only started today after I used full choke on a hot engine. I had one of the other riders ask me if I was trying to immitate a Harley......

[AussieValk]

Try removing that in-line filter you added.    I mean totally remove & put it back like it was,

I tried to add an in-line filter in mine about 98 or so.    It kept acting like it was starving for fuel and cutting out cylinders,    Since that was the last modification I had made at the time, I took it out and only had 1 misfire since.   That was when I fried the starter relay connector,,

Let us know the out come.

+1 What Rj said

Also make sure your fuel line is fairly straight. I put a extra long line on to make pulling the tank easier, but it would make a s shape verticly and trap air in the lines, it the acted as your does.

I have one of those quick disconnect hose attachments which lets me get the tank up a bit higher before removal. It does make a vertical loop so maybe that could be a problem. I'd hate to have to get rid of that because it makes it so much easier to get the tank off, and I dont have the fuel spillage either. I might have to see if I can re-route it.

[R J]

If you do not have too much EXCESS hose on your quick disconnect, I doubt very much if that is the problem.....................

I also like extra filters to get the crap in the gas from entering the carbs,  I had about 9,000 miles on MGM when I added a filter, 2" one.   Ran beautiful until the 1st time I got caught in stop & go.    We were on a funeral run for a fallen brother.......    I had to pull out & set on the grass like a damn idiot, & all these Harley's are poppin along no problem.         Tried to recreate the problem with no success.     Went on an extended trip, about 28,000 miles.    It acted up again in Vegas.   Messed with it and finally decided to check that filter, had some crud in it but not enough to cause a problem.   Removed the filter, lock stock & barrel.   Finished the trip, was in Arizona, New Mexico & several other Southern states including that one that is hot & humid in the summer, think it is called Floor-Au-Da.   Got back home, put on a larger diameter filter, About 7 weeks later, we got into the same problem, this was at about 35,000 miles.

Took it out again, replaced the hose with a new one that wasn't all spliced together.   It now has 242,000 & change with no more problems,,,,,

I'm telling you this so you will quit screwing around trying to get a filter to work.  I been there, done that & still have the 'T' shirt.

[Ricky-D]

Hopefully someone here can help with this one.

I've had the engine cut out, as if it's run out of fuel, today after sitting in stop/start traffic for ten minutes or so. I was low on fuel, but not on reserve, and it has happened before (in traffic) with about 1/3 of a tank left. It seems that the bike gets warm and the fan cuts in which is normal, then it begins to cough and splutter. If I catch it in time and give it a few revs sometimes thats enough to get it running again. But today it died and it was hard to get started again. Tried it on reserve but no luck. When I got it running using the choke and reserve, it sounded like it was running on five cylinders. I jumped on it and a little way down the road it fired right up and I switched fuel back to normal and got to the service station to fuel up.

I've had the petcock off and put the kit through it, changed the filter (both in tank and one in-line), the vent hose is good with no kinks or blockages and I don't think it is the vac lines, or is it?

It seems fuel related as in some junk in the carbs, but it's strange that it only happens as described above, and I'm sure it's not water in the fuel. Could it be spark related? I'm happy to give more of a description if anyone can help.

TIA

You might consider it is still the petcock.

At low idle speed, the petcock is seeing widely spaced vacuum pulses from the carburetor. If there is any problem with the petcock on the vacuum side, the fuel can slow to a trickle or even shut off. Speed up the motor and fuel delivery resumes, how well then depends upon other factors.

***

[AussieValk]

Thanks for all the reply's. I'll remove the filter and replace the fuel lines to start and see how it goes.




Ricky-D, I put that 'Cover Set' kit through the petcock and the bike ran fine. How do I check the vacuum that you refer to?

OK. just went back to shoptalk, and is that the check valve you're meaning re the vacuum? ie. a blockage.

[Ricky-D]

Thanks for all the reply's. I'll remove the filter and replace the fuel lines to start and see how it goes.




Ricky-D, I put that 'Cover Set' kit through the petcock and the bike ran fine. How do I check the vacuum that you refer to?

OK. just went back to shoptalk, and is that the check valve you're meaning re the vacuum? ie. a blockage.

Trying to explain.

The petcock runs off the vacuum from a single cylinder. A single vacuum pulse per two revolutions of the motor.
If the vacuum pulse allows enough gas to pass-through for the motor to continue to run for another two revolutions you are ok.
On the other hand, if there is a problem with the vacuum or the petcock, the gas passing-through may be limited.
At higher motor revolutions a vacuum problem with the petcock may be overcome simply due to the greater/faster number of vacuum pulses.
However at lower motor revolutions (like at idle) the pulses are spaced out and can exacerbate an existing problem with the vacuum/petcock and result in less gas passing through to the carburetors.

***

[Chillerman]

No offense to anyone who has added an inline fuel filter, I had one myself for awhile.  The screen on the OEM petcock is very fine and in my opinion stops any major debris from getting in the carbs.  There is an article somewhere in Shoptalk that asks why anyone would want to add an external filter when the OEM screen is so small.  I can understand with aftermarket petcocks with no screen you might want a fuel filter.  I will have to look for the article I found.

[Chillerman]

I found this from Tim Skelton's website.  Lot's of other info from his main page.

http://www.timskelton.com/valkyrie/tech/petcock.htm