ZG327 RPM Fluctuation

[josephny]

I have a ZG327 and when the throttle is fully open (or 90%) the engine speed continuously varies, as if the governor allows it to rev up and then cuts it back in a continuous cycle.

The engine bogs down somewhat easily.

Can anyone suggest what is going on?

Thank you!

 

[100 td]

Besides the usual, air cleaner, spark plugs, fresh fuel, tank full, fuel filter, has the engine been left for any long periods with fuel sitting in the carby? If so, one possibility is that varnish may have formed in the main jet or nozzle, slightly reducing the orifice size, which will cause hunting and poor performance. If it is that, get an oxy tip cleaner and run it through the main jet and nozzles. You will not be able to see the varnish layer, the orifices will look clear, but a fine layer of varnish does reduce the size and flow of fuel considerably and cause these symptoms. Many other possibilities, this is just one.

 

[josephny]

Besides the usual, air cleaner, spark plugs, fresh fuel, tank full, fuel filter, has the engine been left for any long periods with fuel sitting in the carby? If so, one possibility is that varnish may have formed in the main jet or nozzle, slightly reducing the orifice size, which will cause hunting and poor performance. If it is that, get an oxy tip cleaner and run it through the main jet and nozzles. You will not be able to see the varnish layer, the orifices will look clear, but a fine layer of varnish does reduce the size and flow of fuel considerably and cause these symptoms. Many other possibilities, this is just one.

I kept focusing on the governour.

I guess I was in denial about having to clean the carb

Jets clogged makes perfect sense: Somehow (someone?) put paper in my gas tank and I've been cleaning it and the gas lines out since last Summer. I might have been in denial about the possibility of anything getting past the gas lines and fuel filter also.

I add Seafoam to each fill up, but I know it has it's limits.

If only I was as good at cleaning carbs as I am about avoiding doing what I don't want to do....

Thank you for the advice and setting me straight.