Honda gxv630 surging at mid/high speeds

[FloridaRob352]

Engine idles fine at low idle. Give it throttle and it steadily surges. Engage the blade PTO and the surging stops. Pulling a plug wire off each cylinder causes a miss and stops the surging until replaced. Both cylinders identical effect.

This is what I've done:
-Disassemble and clean carb with carb cleaner and compressed air
-replace inline fuel filter and carb inlet filter
-replace air filter
-replace spark plugs
Any suggestions would be greatly appreciated.

 

[Tiger Small Engine]

Engine idles fine at low idle. Give it throttle and it steadily surges. Engage the blade PTO and the surging stops. Pulling a plug wire off each cylinder causes a miss and stops the surging until replaced. Both cylinders identical effect.

This is what I've done:
-Disassemble and clean carb with carb cleaner and compressed air
-replace inline fuel filter and carb inlet filter
-replace air filter
-replace spark plugs
Any suggestions would be greatly appreciated.

1) Clean carburetor again
2) Check for air leaks around carburetor
3) Shorten throttle spring
4) Adjust air/fuel mixture if available
5) Live with it if all else fails

 

[StarTech]

Carb needs a good ultrasonic cleaning as it will deep clean where just spray carburetor is a joke.

But first see if it is a lean burn issue by applying some choke when it is surging. And if a good cleaning it is still surging then a good carb tech should be able to re-jet it to correct for the lean burn issue if adjusting the mixture doesn't help. Note the mixture screws are hidden behind two welch plugs that must be removed to access them.