190E hard starting

My 1988 2.3 190E starts just fine in the mornings when the engine is cold. If you switch it off and then on again within a minute, it starts without a problem. If however, it has been switched off for a while but the engine is still warm, it starts only after the kickstarter has cranked many times (up to 10). It does eventually start every time but this is embarrassing and has already resulted in the loss of one kickstarter. Once started, the engine idles smoothly and accelerates smoothly. I would appreciate some help with this.