excessive vibration

[cuttinggrassiscool]

hi.
i am new here and already have a question. i have a toro 42 inch walk behind with a 12.5 Kawasaki engine. i believe it is the fb460v. recently i had trouble with it starting, after sitting for a bit. it was bit harder to start and ran rough, i took the carb of sprayed it down and tried again. the same problem occurs. it is possible that i missed something when i cleaned it but. it seems odd as i noticed almost no improvement. the problem gets worse when the blades are engaged. i took them of and balanced them (they were as perfect as one can get with a cheap cone balancer, which is what i always used). but it still seems to shake way to much and it wont run smooth. I'm gonna check all the basics like the plug and all filters in a few days. just wondering if anyone had a similar problem that is something beyond the usual. thanks

[Lawn Masters]

first off, get a proper balancer for the blades, that cone thing isnt what I would call a good one. its possible you've got a spindle going out or a flat spot on the belt. if the vibration isnt existant when the deck isnt engaged, check the other belts for flat spots and see if you can find any. if so, replace the belt and it should smooth out.

[Restrorob]

While checking the belts, Check the pulleys also for debris stuck in the grooves, For being warped or bent. Also if a belt does have a flat spot check the pulley for a layer of rubber stuck to the groove, A new belt could cause a vibration when disengaged from this layer of rubber.

[ed2hess]

I only had one of those engines and the starting thing could be a valve problem. The exhaust valve is sometimes the problem,. Now if this is a newer unit disregard this info because they don't burn in short time. This engine has the big conterweight on the crank and that eventually cause trouble but isn't likely the vibration.