Hello everybody,
This spring I bought a new to me 1993 21 foot Mariah bow rider. It has a merc 350 mag and alpha 1 Gen 2. Boat and trailer together weigh in at 4200 lbs with full fuel (30 gallons ) all safety gear, tool kit spare prop extra flluids, and 2 batteries. Its a easyloader single axle trailer with surge brakes. Not sure of its weight. I would guess about 800 lbs putting the boat at about 3400 lbs. The boat had a Rev 4 48-857026-19 prop when I purchased the boat. On the water with two adults and full fuel could get the boat up to about 42 mph at about 3900 rpm. I thought it quite slow for the type of boat and engine. It had a whale tail on it and I took it off and checked the plugs, cap, rotor, throttle opening fully and timing. All looked good but timing was sitting at 0 at 650 rpm. I set timing to 8 and went back out to the lake. Now with just me in the boat it hit 47mph and just under 4300. Better but still slow I think and too low of rpm. Took the plain aluminum 19 inch pitch spare prop, I am guessing the original and tried it. This time out it was a little choppy and got it to 4600 rpm but only 46 mph. getting ready to load the boat at the ramp some Jack ***** passed by the loading area in his wake board boat plowing a huge wake, up went my boat and then down hitting the prop on the ramp....good thing it was the aluminum prop and not stainless. So much for that prop. After that I put the rev4 back on and enjoyed the boat for the next couple months. I had another prop from my Searay and figured to give it a try even though it was a 21 pitch 3blade Vengeance. Out to the lake 2 adults and one kid full fuel and was able to hit 53 mph but at only 4280 rpm. all speeds are by gps and tach readings from a snap-on digital timing light. Speedo has never worked on the boat and the tach is out by 300rpm according to the timing light. I am surprised at the top speed of 53 with 4280 rpm. the same rpm as the rev4 but 6mph more. I would like to know what I should be trying next. Is the vengeance a good prop for my boat type just needing a lower pitch?? or would something else work better. The rev4 was better out of the hole but thats it. The Vengeance taking about 3 seconds to get on plane. One thing I noticed is at about 30 - 35 mph just a little bit of trip and it would porpoise quite a bit. The boat really liked 40 and above then could trim it up quite a bit. Again speeds are gps rpm is from timing light. Leg is stamped 1.5 for ratio. Well thats a little long winded but I need to get the rpm up, I believe the WOT range is 4400 - 4800. Would like to hear what others think. Thanks for reading
This spring I bought a new to me 1993 21 foot Mariah bow rider. It has a merc 350 mag and alpha 1 Gen 2. Boat and trailer together weigh in at 4200 lbs with full fuel (30 gallons ) all safety gear, tool kit spare prop extra flluids, and 2 batteries. Its a easyloader single axle trailer with surge brakes. Not sure of its weight. I would guess about 800 lbs putting the boat at about 3400 lbs. The boat had a Rev 4 48-857026-19 prop when I purchased the boat. On the water with two adults and full fuel could get the boat up to about 42 mph at about 3900 rpm. I thought it quite slow for the type of boat and engine. It had a whale tail on it and I took it off and checked the plugs, cap, rotor, throttle opening fully and timing. All looked good but timing was sitting at 0 at 650 rpm. I set timing to 8 and went back out to the lake. Now with just me in the boat it hit 47mph and just under 4300. Better but still slow I think and too low of rpm. Took the plain aluminum 19 inch pitch spare prop, I am guessing the original and tried it. This time out it was a little choppy and got it to 4600 rpm but only 46 mph. getting ready to load the boat at the ramp some Jack ***** passed by the loading area in his wake board boat plowing a huge wake, up went my boat and then down hitting the prop on the ramp....good thing it was the aluminum prop and not stainless. So much for that prop. After that I put the rev4 back on and enjoyed the boat for the next couple months. I had another prop from my Searay and figured to give it a try even though it was a 21 pitch 3blade Vengeance. Out to the lake 2 adults and one kid full fuel and was able to hit 53 mph but at only 4280 rpm. all speeds are by gps and tach readings from a snap-on digital timing light. Speedo has never worked on the boat and the tach is out by 300rpm according to the timing light. I am surprised at the top speed of 53 with 4280 rpm. the same rpm as the rev4 but 6mph more. I would like to know what I should be trying next. Is the vengeance a good prop for my boat type just needing a lower pitch?? or would something else work better. The rev4 was better out of the hole but thats it. The Vengeance taking about 3 seconds to get on plane. One thing I noticed is at about 30 - 35 mph just a little bit of trip and it would porpoise quite a bit. The boat really liked 40 and above then could trim it up quite a bit. Again speeds are gps rpm is from timing light. Leg is stamped 1.5 for ratio. Well thats a little long winded but I need to get the rpm up, I believe the WOT range is 4400 - 4800. Would like to hear what others think. Thanks for reading
