<Ronald wrote in part: The only way for a max prop to have a blade that does not open at the same time and amount would have to be a gear failure."> In part this is true but in order for the Max prop to work it must open fully for either reverse or forward. To do so relies on the offset blade area from the pivot point and the gearset to be "free rotating". A failure to lubricate the gearset or using the wrong lubrication that gets washed out allows marine growth in the gearset which will prevent the proper operation. We have serviced many of these units and have even found some assembled backwards. I.e. you get really great reverse but weak forward propulsion. We've also seen them assembled with the wrong pitch which is adjustable and should be noted when the using is disassembled for it annual service. All in all a bit of a specialized device that needs to be serviced annually and by someone who knows the unit. The boat owner needs to know what the correct settings are for his boat so the service person can set it up correctly when he repacks it with grease. It is also imperative to change the zinc annually which is a proprietary zinc. We have also found that you need to pause when going from forward to reverse or the other way around for two reasons. One the blades need to reverse to their stops before the full thrust hits them and more importantly the transmissions are not designed for the shock load of a engagement of the blade. A non feathering prop loads the transmission all the time and the load ramps up as the rpm. With a feathering prop the rpm is coming up if the throttle is advanced while the blades are still rotating into position. As they finally hit the stops the rpm is already up a bit and the load hits the clutch pack. The trans pressure isn't high so there is slippage. We've seen transmission clutch packs fail in under a thousand hours directly traceable to this action of in and out of gear without the delay required. Operator error for the most part but you won't find it explained in anyone's manual so how to know? One of the by products of electric controls is that a delay can be set to allow for this. Set too long will drive an operator crazy as it appears that "nothing is happening" when the gearshift is moved. Set to low and the transmission is suffering. The folding props are a lot simpler, IMHO, require less service and you can use conventional shaft zincs. They do tend to be harder on the cutlass bearings if they do run with slightly different blade extension, however. Dave & Nancy Swan Song Roughwater 58