I have this problem with my bike(79special), I'll ride for about 40 mins fine, than all of the sudden it will start running rough. It will act like its running out of gas but it has plenty of gas. it will sputter for about a minute then die.I'll let it sit for a few minutes and try starting. it will start and run fine after it died. Should I just clean the carbs? Any thoughts, comments or tips will be much appreciated
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Bike runs fine, dies, then runs fine agian
- Thread starter Jerritt
- Start date
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- Tags
- carburetors engine
pamcopete
Ride.Enjoy.Life is Simple
Jerritt,
Probably fuel starvation caused by one of several possibilities:
1. Blocked fuel cap vent.
2, Blocked fuel delivery hose from the petcock to the carbs.
3. Blocked fuel filter.
4. Low fuel in the tank.
The bike runs fine for 40 miles but then the carbs are starved by one of the conditions listed. You stop and wait a few minutes. The fuel slowly trickles into the carb bowls. The bike starts up just fine and runs until the carbs are empty again.
Of course, we remember the expression "if you think your have carb problems, check the ignition" and in this case it could be a bad coil that quits when it gets hot and comes back to life when it cools down, except you have a '79 with two coils, so only one of the coils and one cylinder would fail, not both at the same time, unless you have an aftermarket ignition that only uses one coil.
Probably fuel starvation caused by one of several possibilities:
1. Blocked fuel cap vent.
2, Blocked fuel delivery hose from the petcock to the carbs.
3. Blocked fuel filter.
4. Low fuel in the tank.
The bike runs fine for 40 miles but then the carbs are starved by one of the conditions listed. You stop and wait a few minutes. The fuel slowly trickles into the carb bowls. The bike starts up just fine and runs until the carbs are empty again.
Of course, we remember the expression "if you think your have carb problems, check the ignition" and in this case it could be a bad coil that quits when it gets hot and comes back to life when it cools down, except you have a '79 with two coils, so only one of the coils and one cylinder would fail, not both at the same time, unless you have an aftermarket ignition that only uses one coil.
Does it do that every time?
Also will it run fine after that...Or does it die again after a while?
My first thought is a bad coil... when it heats up it could start acting funky.
My second thought is a charging issue...where your battery is being drained over that time...then needs a few minutes to recharge...doing some testing with a multi-meter may be needed.
Also will it run fine after that...Or does it die again after a while?
My first thought is a bad coil... when it heats up it could start acting funky.
My second thought is a charging issue...where your battery is being drained over that time...then needs a few minutes to recharge...doing some testing with a multi-meter may be needed.
Good points Pamcopete: I forgot the dual coils...so that likely isn't the issue...disregard my post. Vapor lock could be it. Easy to test...simply open the tank when it happens...if you hear a "hiss" sound and bike starts back up (may need to prime) then that would be it.
NONclow
Confirmed Laquer Breather
If not a cap vent issue:
What's the inside of the tank look like (what you can see, of course)?
I'd clean the carbs, AND the petcock(s), AND the tank. New filters aren't a bad idea....
What's the inside of the tank look like (what you can see, of course)?
I'd clean the carbs, AND the petcock(s), AND the tank. New filters aren't a bad idea....
