I don't have much trimming to do, and I just gave up on gas-powered ones for that very reason. I picked up an el-cheapo electric one at Lowe's and slapped a protection/replacement plan on it, 3 years I think, and basically said just forget this.
Last summer, I had to go through a storage area and find some old-school gas cans that didn't leak for mower gas, because mine had some stupid springy mandated release to pour deal on it. The spring broke. And I had a hard time finding a regular old gas cap that would fit the tank.