Throttle Up Problems

[Bubba Prosser]

Good afternoon. I've got a 640 with a Jubilee engine I only use to cut around my pond and ditch bank with a sickle mower. I use it 3 or 4 times a year. It idles good but when I give it throttle it hesitates and stumbles bad until it seems to catch on then it runs pretty good until you throttle down and up again. What would you check first and how? I'm thinking it the carb. Thanks.

 

[Curt Cooke]

A rudimentary check on that situation would be to see if you can have an affect on the stumbling by manipulating the choke. If a little choke cures it, you may have a carburetor problem, dirty, passage plugged, or bad float level. If choking has little or no affect, then your trouble is ignition, points or plugs would be a good place to start the process of elimination.