First time poster, I'm out of ideas and I'm considering just selling the bike now.

PO had the same problem and there was a major gas leak he suspected was the problem. I've repaired that.

Starts rough, once started the idle is fine. Revs smooth all the way up in neutral. But once I try to ride her, she dies at 3.5k rpm. No bog, no popping, just cuts power until she dies. Bike does not turn off.

Things I've done:

Cleaned carbs three times (the PO had jets all switched around)
Checked diaphragms
Checked air filter
Checked for vacuum leaks
Adjusted mixture screw, changes performance but still dies @ 3.5k
New plugs
​​​​​
Only thing not stock is aftermarket regulator/rectifier.

Do you guys have any ideas? What would cause problems only under load?

Thanks,

​​​​​Kevin

 

does it die if you try and ease through 3.5k?

mine did the same thing.. but didnt die, just wouldnt let me past that rev range. turned out i was majorly rich and putting smaller mains in did the trick.

First thing i can think of is the fuel pump.. as u drink what is gravity fed into the carbs it just runs out of fuel, as the pump is causing a sort of blockage ur getting less than pure gravity. connect the tank straight to the carbs and see if the prob gets better, then u know u need a new pump.

Another idea if its no that, If you pull the clutch in when u hit the problem does the motor fall back to idle or die totally? If its dieing totally, i would try and rig a voltmeter to the battery and watch it as u try and push past 3.5k.. if the voltage goes really high, i believe the CDI switches itself off to protect itself.

 

A couple things. One, is your Speedometer working? There is a signal from it that controls the Air Vent solenoid. It switches off after the bike reaches 12 mph. Do you have the little air vents attached that are below the headlight? One thing people do is to just disconnect the Air Vent solenoid all together. The connector is on the right side of the frame near the carburetors, 2 pin connector.