The Pineapple Racing Yoohoo Belt™ is a proven means to avoid a slipping water pump(1974-1991) on a Mazda rotary engine without an air pump†. The alternator belt alone does not provide enough contact with the water pump, so it tends to slip when properly tensioned. If overtightened to stop the slipping, the belt may break and/or cause damage to the engine from side-loading the end of the eccentric shaft, as well as cause damage to your alternator and water pump bearings.

Dual belt alternator pulley setups are a poor alternative because most nominally correct sized belts vary in actual length, making them impossible to tension equally. So, either one belt is too loose and slips or one is overtightened and eventually breaks. Further, if one belt breaks, it usually takes out the other belt at the same time.

The Yoohoo Belt™ runs from the main pulley to the water pump and back. There is no tensioning adjustment. You just walk the belt onto both pulleys and the tension will be correct. It can be a little loose because there is so much contact area that it will not slip. Also, if the alternator belt happens to break, the water pump is still driven. You can drive a lot farther without an alternator than without a water pump, which can be important in order to reach the next exit or the nearest parking lot.

†Product is intended for off-road use only. Do not install on emissions controlled vehicle.