Masport mower running funny

[madderdog]

I have just bought a visually good condition Masport 480 mower second hand. It cuts fine but the engine seems to run funny. It doesn't run at a constant rev speed but appears to speed up and slow down. Don't think this is meant to happen. Can anyone explain what maybe wrong or if indeed it is strange but normal

[Batpig]

Dear Madderdog,

Any chance of posting a fotor of the motor? (well, a photo anyway...)

Best Wishes,
Batpig.

[Uncle Bob]

I believe that's caused by the governor. Possibly a spring has come off it so it's flapping around in the wind generated by the magneto fan. Or could a fuel starvation problem.

[Godzilla73]

G'day,

Check the air filter foam insert, prob only the side facing out will be dirty. You can either wash it out with plain old dishwashing detergent, ring it out, get some air filter oil and give it a coat then slap it back in or, buy a replacement for $10 or so. Your call...