trip313
08-12-2005, 01:56 PM
I have a 1987 Marlin Sidewinder with a 1991 Merc 200. I am running with 14" of set back and a Merc 25" pitch laser prop. I have put a straight edge on the bottom of the boat and there does not seem to be any hook in the hull. The boat does not have a pad. I have to use a lot of positive trim to "fly the hull". I can get the boat up to about 62-MPH (off a speedo) at about 5900 RPM. I would like to purchase a manual jack plate (can't afford the hydraulic ones). My questions are 1) When starting out what size increments should I raise the motor as I experiment with the jack plate? 2) I do not see myself getting a chopper or clever prop (over the hub style) but something like a Mazco HP4 or a Merc Trophy (both 4" diameter hubs). With this in mind how do I determine what engine height is best? 3) How can I choose a pitch for a new prop until I know my engine height? I anticipate that as I raise the motor (pull prop blade out of the water) I will be able to increase the pitch for more top speed & to keep my engine RPMs down. 4) Does any one have any suggestions on prop slection based on top speed and not wanting to go with an over the hub style?
In conjuction with the jack plate & prop questions I have some questions on what lower unit to go with. I know Merc has three lower unit housing to choose from. The stock one (which is what is on my 200), the torquemaster, & the sportmaster. If I am going to start to use a jack plate which lower unit do I want? I know maintaining water pressure is the main concern as you raise the motor. The stock lower unit has the water pick-ups above the bullet (housing for the prop shaft). The torquemaster seems to have the water pick-ups in the same location (I am not sure as I have never seen one in real life). And the sportmaster has the nose cone & low water pick-ups on the bottom of the bullet. I have read in several locations that you do not want the nose cone until about 80-MPH. So how do I choose a lower unit? If seems to me that I cannot get the low water pick-ups without getting a nose cone and without the low water pick-ups I cannot raise my motor as high as I might need to to get the best performance out of my boat/engine combination. Or due to the fact that I want to stay with a through the hub style prop will I not be raising my motor high engouth that low water pick-ups will be necessary? Also can anyone suggest some shops or websites that sell used or rebuilt lower units?
Sorry for the long set of questions.
In conjuction with the jack plate & prop questions I have some questions on what lower unit to go with. I know Merc has three lower unit housing to choose from. The stock one (which is what is on my 200), the torquemaster, & the sportmaster. If I am going to start to use a jack plate which lower unit do I want? I know maintaining water pressure is the main concern as you raise the motor. The stock lower unit has the water pick-ups above the bullet (housing for the prop shaft). The torquemaster seems to have the water pick-ups in the same location (I am not sure as I have never seen one in real life). And the sportmaster has the nose cone & low water pick-ups on the bottom of the bullet. I have read in several locations that you do not want the nose cone until about 80-MPH. So how do I choose a lower unit? If seems to me that I cannot get the low water pick-ups without getting a nose cone and without the low water pick-ups I cannot raise my motor as high as I might need to to get the best performance out of my boat/engine combination. Or due to the fact that I want to stay with a through the hub style prop will I not be raising my motor high engouth that low water pick-ups will be necessary? Also can anyone suggest some shops or websites that sell used or rebuilt lower units?
Sorry for the long set of questions.