Dying on the run

[roxy1124]

I have a 2003 Yamaha roadstar silverado 1600. It has 68,000 miles on it. Well I was riding the 3 sisters in texas today and when. I got to medina to start it my bike died when I was going about 30mph. Well i down shifted to 2nd and it started right back up. This happened 3 more times. So I bought a new fuel filter and put a thing of seafoam in it. Things seemed goood. Road 2 of the sisters and fixing to start the 3rd one. My bike died going about 70mph. Down shifted hit the start button and it came back on. Did this about 8 times in a matter of 15 min so I abandoned my ride and headed back to Fredericksburg as long as I kept it in 4th gear I could run about 60mph and was fine. Get 20 miles out if fredricksburg and upshifted to 5th again and was running 75-80 mph the last 20 miles with no problems. Any ideas of why

[Shores]

Crap in the fuel from sitting all winter?

[SKWEARpeg]

What Shores said.
Drain the carb bowl, and about a half gallon of fuel out of the tank at the petcock, with the petcock on reserve.
Capture the fuel in something with clear sides so you can check for the presence of contaminates in the fuel.

[Duke]

If you have contaminants in the fuel, the first place it's going to end up is on the fuel strainers on the petcock inlet tubes. The only way to check them out, is to remove the petcock.
This is what I removed from my petcocks and just rely on the main fuel filter.

[roxy1124]

Ok I'll try that. I've road it a few times a week all year to work and back and on weekends. This is 1st time it's done it. But I'll drain it when I get home from the honeymoon and see what I capture

[roxy1124]

ok went ahead and drained tank and everything. and replaced pedcock. ran good for the next dozen rides but the last couple times it would randomly die. once going 45mph and then again going about 70mph. drop it down to 2nd gear and hit the start button and she starts right back up. at a loss here. up until the dying part she runs great. then all of a sudden bam she dies.

[Txulrich]

Please take some time and fill in your profile. It helps us to know the current state of your bike when we offer advice. We can be that much more accurrate.

Did you also change the fuel filter? Are you still running the fuel pump? It might be going bad. You should carry a piece of rubber fuel line. You can bypasss the pump if it fails.

[SKWEARpeg]

Since you drained the tank, and it’s still doing it, I’d wonder if the tank is venting properly, or the pump may be failing.
How is your mileage?

To check the pump, simply get a piece of 5/16 fuel line and run it directly from the petcock, to the carb. Bypass the filter and pump altogether. Start riding it. If you have no more problems, then you know it was the pump.
As far as the tank not venting properly, there are two different problems that can cause it. One is the rollover valve getting stuck closed, or something blocking the end of the vent line, below the bike. The second, is at the elbow on the front right corner of the tank where the tank vent line connects. The latter is a bit harder to fix. Venting the cap properly usually fixes either problem...if that is what it is.

[Spydr]

Am I the only one that suspects an electrical problem?

[roadiemort]

Nope, Check coil connections.

[SKWEARpeg]

Battery connection maybe?
PU coil almost done. Not a common problem, but certainly possible.

[Spydr]

That's the first thing that came to mind with the behavior he described .

[Txulrich]

Am I the only one that suspects an electrical problem?

It's a possibility, but checking/changing the fuel filter and bypassing the pump are cheap easy things to do (and more probable) before trying to chase down an electrical problem.

[Spydr]

I get that Joe. But if the symptoms seem like electrical to Me, I'm not going to look for a possible fuel issue. Even if it Is the easiest to check & eliminate.

[Txulrich]

Don't forget that a dying fuel pump will act like an electrical issue. It will be intermittant before it fails completely.

[roxy1124]

hey sorry its been a while. bike ran fine for a while then started doing it again. ive replaced fuel filter and pump. bypassed fuel pump and still does it. usually only does it after bike has warmed up good and choke is off. the other day it did it after I road for about 70 miles and stopped and wouldn't start again 3 miles from house. towed it home and that is where it is sitting

[davej]

You are gonna have to determine if the issue is fuel or spark related. If it won't start right now give it a little spray of starting fluid. If it starts then it is a fuel related issue if it don't start for a second or 2 it is electrical

[Father Pobasturd]

Water in the fuel. Very humid where he lives and this year has been a banner year for rain. Check for water.

[roxy1124]

not water in fuel. it will start and run. idle for however long you want it to idle. I let it idle for about 30 min while I was poking at wires to see if I had a short somewhere. didn't die or anything. got on bike and road down road and about a quarter mile down road just shut off like someone turned off key. down shifted and hit the start button and it started back up. turned around to go home and halfway home did it again. like before coasted and down shifted and hit start button and came back on then drove to garage

[davej]

Have you disconnected the rubber fuel tank vent hose on the tank vent that is under the speedo cover? A partially plugged vent line/roll over valve could do what you are describing.

[Duke]

Just a thought, but check the kill switch and the kick stand switch. They might be having electrical intermittent problems?

[Scrap]

Sounds suspiciously like the kick stand switch. The jerk when restarting on the run is closing the switch until the stand drops enough to open the switch again.

Has the bike been serviced lately? Mechanic have a habit of spraying WD40 (or similar) on the kick stand to give it a smooth operation.

[Doc_V]

not water in fuel. it will start and run. idle for however long you want it to idle. I let it idle for about 30 min while I was poking at wires to see if I had a short somewhere. didn't die or anything. got on bike and road down road and about a quarter mile down road just shut off like someone turned off key. down shifted and hit the start button and it started back up. turned around to go home and halfway home did it again. like before coasted and down shifted and hit start button and came back on then drove to garage

FYI, when it's sitting, water doesn't mix with the fuel and effect running under mild conditions like idle or going easy, but when you open the throttle, it begins sucking hard enough that the water now gets sucked in too. Don't recall if you've already done it, but drain the *float bowl*, you could have water in there. Capture the fuel in a clear container and you should be able to clearly see if there's any water.

As for fuel vs electrical, start with the easy stuff to fix then move on to the harder. regardless if its fuel or electric.

Also, you never mentioned anything about the tank vent. If the vent is partially clogged, it won't show under light load, but when you open her up and start sucking more fuel, a vacuum forms inside the tank and you starve for fuel. Once it has a moment to catch up with the motor off, you're fine again until demand exceeds the ability for the vent to work. It wouldn't hurt to just pull the vent line off the top of the tank and see what happens. I wouldn't' do it with more than about a half a tank, to be safe.

Lastly, you never mentioned if you'd fueled up shortly before the problem started. If you got gas and the station had water in their underground tanks, it could have caused the problem.

[roxy1124]

ill have to look at the kickstand kill switch when I get off today. as for fuel ive drained tank 3 times and put new vent line on it. each time I put in clear container thinking maybe it was water in gas but it looked good each time. also replace fuel filter and fuel lines as well as the petcock thinking I might have crap in it. but still keeps doing the same thing. I will test the kickstand switch later and see what it reads

[Jclevesque]

Have you taken the float bowl off? Does it move properly? Could be a partially stuck float.....uses up gas in bowl, doesnt allow enough to go by, bike uses up what is in there until nothing then dies...just a thought.

[Doc_V]

What Jclevesque said.