Bike won't start after running out of fuel in reserve?

Detonation · Wed Sep 11, 2013 6:01 am

I ran out of petrol as i was pulling into the petrol station, filled up, put bike to prime and Bike won't start, hour of bumping it later I walk it up the road home.

Today I took the airbox off
Added 4 drops of fuel to each air intake
Reattached the tank a vroom, starts up straight away.

I've had this problem once before when my electrics went, I ran out of fuel trying to start it up with fried coils then when I replaced the coils it wouldn't start with fresh fuel, 4 drops into each air intake and it started then aswell!

(Video is from the time I replaced coils)
http://youtu.be/pHuB_gMn4jM

Has anyone else had it that it won't start after running out of fuel?

The vacuum hoses where all sucking ok

The float bowls where filling

It just wouldn't start until I put fuel in the air intake and works fine again afterwards.

Am I missing some underlying problem?

Bigfeet51 · Wed Sep 11, 2013 7:15 am

It has happen to me twice to the point that I drained the battery trying to get it started.

1Oldman · Wed Sep 11, 2013 7:54 am

It's a pretty common problem and hard to do anything about out on the road. A can of starting fluid helps, if you can get hold of one.

Detonation · Wed Sep 11, 2013 7:57 am

Yer I'm going to try getting hold of some quick start and just keep that in my top box with the tools needed to get tank off just incase I manage to run it out again

1Oldman · Wed Sep 11, 2013 8:02 am

Detonation wrote:Yer I'm going to try getting hold of some quick start and just keep that in my top box with the tools needed to get tank off just incase I manage to run it out again

You know of course, once you do that it will never happen again. But maybe you'll be able to help a stranded buddy out. :brow:

cicatriz63 · Wed Feb 22, 2017 6:55 pm

I know this is an old thread but anyone have any new ideas what might cause this? I had a similar thing happen today. Had the bike out and it ran FANTASTIC since I rebuilt the carbs and all that good stuff. Then I am going down the highway and go to turn off and it starts sputtering then stalls out in the middle of the highway

. I switch it over to reserve and I am able to get it started enough to get me into the parking lot of where I'm going. Thinking I definitely have enough gas to get me to my house up the road, I start it up and it starts going but I can tell something doesn't feel right, running very sluggish. Then I get to the bottom of my hill and it just dies. Refuses to start. I drained the battery trying to get it started. Looking in the tank I can clearly see that there is gas just below the main tube. I just rebuilt the petcock and I know gas flows freely while in prime, but the thing just would.not.start. If I pull the choke all the way out it will start for a second and then try to run and then die. I had my buddy bring me some gas and once I filled it up, flipped it to ON and it started right up. WTF?? Could it be the fuel filter? I used the one from autozone from another thread and its the only thing I can think of getting in the way.

xjardin · Wed Feb 22, 2017 7:34 pm

Sounds like the problem I had with my petcock. In my case, the 90º vacuum fitting on the petcock was loose and popping off. Engine sputtered and died just like you described. JB weld solved that problem in the long term. In the short term (on the side of the road) I got it running again by turning the petcock to "PRIME," letting it sit for a few minutes, then cranking it while fiddling with the enrichment knob. This was the fix after almost killing the battery cranking it.

If you didn't know, the petcock is vacuum operated. When the petcock is turned to "ON," fuel only flows when there is a vacuum on the petcock, i. e. the engine is running. "PRIME" allows fuel to flow directly. My guess is some problem with the petcock system, then the carb bowls are drained and it's a b***h to start again.

Check the vacuum line going to the petcock for cracks and make sure the ends are secure. If those are good then there could be a problem with the internals of your petcock (clogged or blown out gaskets). In that case, check out the petcock rebuild thread on the wall, in Fuel Systems howto's.

Shimonu · Thu Feb 23, 2017 3:06 am

xjardin wrote: ↑
Wed Feb 22, 2017 7:34 pm
Sounds like the problem I had with my petcock. In my case, the 90º vacuum fitting on the petcock was loose and popping off. Engine sputtered and died just like you described. JB weld solved that problem in the long term. In the short term (on the side of the road) I got it running again by turning the petcock to "PRIME," letting it sit for a few minutes, then cranking it while fiddling with the enrichment knob. This was the fix after almost killing the battery cranking it.

If you didn't know, the petcock is vacuum operated. When the petcock is turned to "ON," fuel only flows when there is a vacuum on the petcock, i. e. the engine is running. "PRIME" allows fuel to flow directly. My guess is some problem with the petcock system, then the carb bowls are drained and it's a b***h to start again.

Check the vacuum line going to the petcock for cracks and make sure the ends are secure. If those are good then there could be a problem with the internals of your petcock (clogged or blown out gaskets). In that case, check out the petcock rebuild thread on the wall, in Fuel Systems howto's.

But if the petcock was the issue, shouldn't the bike have started when he had it on PRIME?

I would be very interested in hearing thoughts on this. I have been trying to start mine with the tank off and just putting gas in the carbs and I've been thinking the carbs have been blocked but it still won't start after I tried cleaning them. Now in my case they could still be filled with dirt but this behaviour could also be affecting.

cicatriz63 · Thu Feb 23, 2017 8:17 am

I rebuilt the petcock when I rebuilt the carbs so it "should" be working properly now. Before when I took the tank off to get to the carbs, gas was flowing while in the ON position. The petcock rebuild kit fixed that. When I have the tank off and the petcock in PRIME, gas flows freely. I had it set to PRIME for a good 10 minutes and it still just would not start. Once my buddy brought me some gas, I turned it to the ON position and it fired right up like nothing was wrong. I will double check the vacuum hoses. I did notice that the elbow fitting did move slightly when I was putting the hoses on and off, but it was still tight. But why would it work perfectly fine with a full tank in the ON position?

xjardin · Thu Feb 23, 2017 12:14 pm

Hmm yeah it didn't make sense to me either but what you described sounded exactly like what happened to me. If it's not the petcock it does sound like some fuel delivery problem. Mine had a full tank but still would not start right away after putting the vacuum line back on. Like I said, my theory is the carb bowls get dry then then it's a b***h to start.