Today my wife and I and some friends took a little trip down to Daytona. We went I-95 on the way down (SUCKS with no windshield!!!) and then came back US1. We were basically running between 65-75 the whole trip. We filled up before we left and as we were coming back I noticed I was getting really low on fuel and was thinking I need to stop at the next station. But I only had gone 115 miles on the tank so I figured I had a little more since I usually go around 130 before filling up and have never had to go to reserve.
WRONG! She started coughing and sputtering so I pulled over to a side road. I figured I would just switch to reserve and go to the next station that was less than a mile away. Wrong again. I switched to reserve and no crank. Tried and tried but no luck. I switched to off thinking something was just wrong with the petcock, no luck. So my buddy went on up to the gas station and bought a small can and some gas and brought it back to me. I dumped it in the tank, put the petcock on run and was good to go.
Now, I have two issues. I can't crank the bike up at all without giving it some throttle. And after a bit the idle drops and it stalls. My thought is that I probably got some crap from the tank in the carbs and it's clogging something, right?
The other issue is with the petcock. Why did reserve not work? When I got home I moved it to reserve and it cranked up fine, with me giving it some throttle. But any thoughts on why it will work off of reserve but not when it seems like it should? Could there be something wrong in the petcock so that reserve is acting like normal run and vice versa?
I really don't want to pull the carbs off but I have been contemplating doing an ear shave. If I have to pull the carbs to clean them I might as well re-jet them and pull off all the emissions crap while I'm in there I guess.
Glad you got the bike running again and got home ok with the wife.
Several times you use the term that the engine would, or would not, "crank" or "crank up".
To me that means the starter motor would not crank the engine over. In your situation that seems illogical.
Just running out of gas should not affect the electrical system of the starter motor.
I think what you are actually trying to say is that even though the starter cranked the engine over, it would not start and run.
Is that correct?
I had a similar experince with running out of gas and the petcock "RES"(erve) function not working.
As a rule I refuel before I have switch to reserve, but mistakenly thought I could make one more commute to work and fuel up on the way home one day last summer.
I have run on the reserve position purposely several times when the tank's fuel level was between 1/4 and Full, just to be sure it was functional and there was not any water or debris sitting down there waiting to plug the reserve pickup tube when I needed it.
On the day previously mentioned I believe the gas gauge was probably closer to 1/8 rather than 1/4 full when I fired the bike up after work, about 4 or 5 pm. It is about 6-7 miles to the card lock station where I usually fuel up. It was warm enough ride in a T-shirt and jeans, but not really hot, perhaps 70-75*F.
I had ridden about 2 miles when the engine began to lose power. It took a few seconds of the engine stumbling before I really believed I needed to switch to reserve and rotated the fuel valve/petcock lever ahead. The engine continued to stumble as I coaxed it on down a slight grade wondering how long it was going to take for the reserve gas to get to the carbs. The Vulcan had stumbled and coasted about another mile before I had to pull over and park on the side of the road.
Here is a question for the carb gurus out there. Should there be enough vacuum developed in the engine, to keep the petcock operational, when the bike is stumbling along at 15-20 mph in 5th gear and the clutch still engaged so the rear tire is keeping the engine turning over?
Seems like it should be enough vacuum to me, but the reserve function did not work on that day.
I then opened the tank and rocked the bike side to side to determine how much gas was still in there. It seemed there was enough that the bike should start, but would not on either RUN or RESERVE
. I QUIT CRANKING BEFORE RUNNING THE BATTERY DOWN, as that would have just caused another problem. After an hour or so, I finally got a gallon of gas to pour in to the tank and the engine fired right up and would run in either RUN or RES position.
I still do not know why RES would not pick up fuel when the fuel level got down to where I really needed it to work.
First thing I need to do is some re-testing by switching the fuel from RUN to OFF on a deserted road at 30 mph with plenty of gas in the tank and riding for a mile, more or less, until it starts to stumble. Then switch to RES to find out how long it takes for my engine to regain power. 3 or 4 similar repetitions should be enough to discover at least if it consistent.
Then if needed I will empty the tank and take it off so I can remove the petcock and examine it for any damage, dirt or corrosion I guess. (Also noticed earlier a little bit of paint chipped off the bottom of the tank right next to the petcock. Will be a good opportunity to fix that little problem too
If I leave the house now with less than a 1/4 tank of gas, I throw a 1 gallon plastic jug of gas in my saddlebag. It fits perfectly. I don't trust the "Bad Girl" not to strand me again until I figure out why she did the first time.
EDIT: OK. Four more guys have posted since I began this long winded piece. It seems from their experience that I may have just given up cranking the starter too soon when the petcock was set on RES(erve).
One winter I ran the carbs dry after pouring Seafoam in the gas. IIRC, in the spring I cranked the engine over for 30 seconds (timed) with a new MF-AGM battery, then let the starter cool for a minute or so before cranking the starter again. I think the engine started within 5 or 10 seconds during that second try.
In the event I do run the battery down, I do carry a set of light weight homemade jumper cables at all times.
Made from 10 feet of 16 GA lamp cord and a pair of battery charger clamps.
Weighs less than a pound, and rolls up small enough to carry in my pocket, but usually rides in the saddlebag.
Got the idea from Gadjet's fix it pages here: