Hi has anyone any advice why my pull start has become jammed I have taken the pull start unit off and it pulls freely but the locating bowl turns freely in the opposite direction but is extremely difficult to turn in the direction it is supposed to go..i have removed the blade and all components under the deck just leaving the shaft and is still very difficult to turn and cannot be turned by the pull start..it was working fine when put away at the weekend.. I am at a loss as to what could have caused this..any help would be very much apricated