so i hav a problem that ive never ever come across in a 240....... when i start it it shakes very very violently then cuts off on me and it sounds like a lawn mower sortve when u give it gas. it stays idling very very low . i talked to someone bout it and they said theyve only seen problems like that in Rx-7 and rotary engines. its very weird. think its my spark plugs? or i need a tune up.....very very bad?