HELP bike keeps dying on longer rides

I am sitting on the side of the high way, my bike keeps losing power. I will ride along and then it feels like no matter how hard I rev it I can’t get anything out of it and I slowly lose power. I pull off to the side of the road and as I coast the engine dies. Is it not getting fuel? The mechanic said he bypassed the vacuum petcock. Appreciate any input.

 

Is air getting into the fuel tank? That will make it splutter to a stop due to fuel starvation. Open the tank cap to see if it starts.

 

Ok on my way home, just died after about 20 miles, I have been opening the fuel cap after each time it dies on me, on the way to my destination it was able to restart but by the 4th and 5th time it was struggling to restart

 

Well it’s completely dead now, either the battery is too low from me trying to restart it or the solenoid went bad but it just flashes the oil sign and won’t turn over. Wife is on her way to pick me up and I will take the battery home

 

Thinking of replacing the pet cock and maki g it a vacuum based again and cleaning the gas cap. Put in an inline filter. Pull the carbs, I want to change the jet size and air filter type anyway.

 

Does it restart after it sits a while? Or did it before the solenoid went out? Maybe a restriction in the new petcock or fuel line. You can pull the fuel line and switch it ON...just see how freely the gas flows as a quick check.

 

How about the tank breather?

 

It did restart if it sat for a while but each consecutive time it got a little harder, I got frustrated and tried to hold the start button and rev it back to get it going and then it died. Battery is fully charged but now just emits a singular click so the solenoid is probably fried.

the vacuum petcock was bypassed so whenever I pull the fuel line it comes out. Might go through and see if I can switch it back to vacuum, I have a broken spare and perhaps I can mix and match

 

Not sure what this refers to? The gas cap or opening it after it dies?

 

Is your fuel routed correctly?

 

Fuel cap and filter are good suggestions. Have you checked valve clearances? If they are out of spec on the tight end the valves will not close all the way once everything warms up and expands, results in a loss of compression which equals loss of power nad a hard or no-start situation. Will act fine once cooled down but the cycle will repeat.

 

To my knowledge yes, petcock is on, and goes to the t tube of the carbs

 

Yes, I completed a valve clearance check and got them into spec. I am talking the valve cover off since oil is leaking from the donuts on the braking side of the bike and applying RVT so I will recheck them while in there.
How long does it take to warm up? I have been on 15 min rides in the hot sun and it wasn’t an issue.
Carbs were synched and unfortunately it runs rich. Couldn’t get to the Bunsen blue without the air fuel screws all the way in.

 

I meant does the pipe have any high points where air could be interfering with fuel flow? I should have explained this better. @Melnic had a high point in the fuel line but not sure if that was the problem on his machine.

 

You'd know within 15-30 minutes of riding.

This isn't right, it should die with the screws all the way in.

 

My thoughts exactly. So when I changed a couple I was unable to get the bike to start. My next action was to back them a half turn out. The bike was able to start maintain idle and ride well. I am super confident that the mechanic jetted it too rich. So next steps I’m planning are to go over the petcock and check what numbered jets are in my carbs replace the air filter and switch back to original jets

 

The petcock originally was a vacuum style. It would have 3 settings
ON, RES, PRI (On, Reserve, Prime).
There would be one thicker tube to the carb set and a smaller tube to one of the vacuum taps between carb and intake on the intake boots.
Common thing (my bike was like this) is they pull out the vacuum tap tube and plug the end, then put a nipple cap where they unplugged it from the vacuum tap (all 4 of the carb boots then have nipple plugs).
To run the bike you would then have to leave it on PRI which is pulling from the REserve level, To turn off, you turn it to ON or RES.

Some people replace with a manual petcock that will say ON, OFF, RES. Again, the carb nipples are all plugged but there is no vacuum line.

Figure out which you have.
That being said, If you have fuel flow but the bike dies 10,20,30 mins into the ride, and if letting it sit 10-15 minutes allows it to start and run, you have a fuel flow issue. If its not the petcock, its likely gunk in the little screens under the carb needle housing. Get some extra fuel line to troubleshoot.
You also can troubleshoot fuel flow issues by having clear tubing connected to the bowl drains and look at the bowl levels at the beginning and then when the trouble starts. I had this issue when the screens I had were clogging.

 

Check your alternator output at about 2000 rpms. You may be running on battery which drains it while you ride. I had a similiar problem and found low alternator output. Replaced the brushes and that solved the problem. But if you have an old weak battery it may not be taking a charge and is too weak to start the engine. I've had that problem also, and a new battery solved the problem.

 

And that’s the part where I am confused about what he did. He put a nipple cap on the carb boot and I do not see any caps on the vacuum tube of the petcock. Along with that he said not to change the setting and to leave it on the “on” position.

 

The battery has been on a trickle charger but that’s a great idea. I will have to look up how to do this, I did change some components of the alternator years ago, but easily could have messed something up or something went bad since then.