Sport Series. There is NO serial-to-year cross-reference chart for 1997 and later motors. The prop to use will be 4" in pitch less than the prop that was used during the test. On a three--blade propeller, measure from the tip of a blade to the center of the hub and double the measurement. I really appreciate all your help and info on the jackplate. The boat just feels safer. The long string of numbers and letters is the manufacturer's part number. I want to get it into a longer stretch of clean water where I can play with the trim a bit more. Powered by: Ultimate Bulletin Board, Freeware Version 2000Purchase our Licensed Version- which adds many more features! You can also help identify the propeller by giving some more detail about it, such as: --the number of blades--the diameter of the hub--the length of the hub--the arrangement of the supports between in the inner and outer hub--and, of course, it goes without saying in this digital age and global connected internet, you might give some thought to posting a digital image of the propeller. I am going to test it in 'real world' conditions, i.e. Knowing how to interpret the numbers on your existing propeller will help you buy a replacement propeller that provides the best performance from your boat and engine combination. Example: Mine is a 1985 inline 4 cylinder 140 Mercrusier, with a diameter of 14 inches, a pitch of 19, and a standard rotation. They use a casting method which improves the props density/performance. Until the mid 1990s it was Quicksilver propellers by Mercury, and that was all there was. I'll run the number when I go to work on Fri and see what it crosses to but I don't think that back in the rubber hub days they … While diameter and pitch will affect the performance of the boat, the material that the propeller is made of will not. The local prop shop gave me 2 used propelers try, and this was one of them. 4 - 6 HP 7.5 - 9.9 HP 15 - 25 HP A lower pitch will increase the acceleration of a boat, while a higher pitch will increase the top speed, Overton's explains. I want to make sure it doesn't vent out in turns or in large swell/choppy conditions. Since it's a Merc product I asssume it's actually 21" of pitch. profile | register | author help. turns, into swell, down swell, full load, etc. http://sites.mercurymarine.com/portal/page?_pageid=126,48417& _dad=portal&_schema=PORTAL. Aluminum is the most common material used to make propellers. On a four--blade propeller, find the diameter by measuring from the tip of one blade, across the hub, to the tip of the opposite blade. I am extremely happy thus far with the jackplate/ new prop combination on this boat. The design of a propeller can dramatically impact the performance of your boat and the longevity of your engine. There are no industrywide rules to interpret this number. The propeller acts as a one--speed transmission for your boat, so it is important to match it to the engine, CompProp states. Mirage Plus, High Five, Trophy Sport, Vengeance, Laser II, Black Max, Bravo Two ... Search by serial number to find the exact part you need. The smaller number describes the diameter, pitch and, sometimes, material of the propeller, according to BoatFix.com. The diameter and pitch can be separated by the letter "X," CompProp states. We WILL need your serial number to look up correct parts. Once again thanks Sal I'll send you some pics soon. It is a Mercury prop if the number starts with 48. Gauges & Controls ... browsing experience. ContinuousWave: The Whaler GAM or General Area. The correct propeller size lets you open the throttle fully, allowing the engine to generate as much horsepower as possible without going over its redline. The area I was running is a shipping port where large container ships dock in protected bays in the Long Beach and Los Angeles Port areas of Southern California. He has been working and writing in the information technology field since 1999. A propeller diameter that's too large will hit other parts of the boat. This prop seemed to work real well for this set-up. You can find your Mercury outboard serial number and model number on an ID tag on … I am not 100% on this prop just yet however. There are two sets of numbers stamped on every propeller. You can also just enter the part number into GOOGLE search and see what results you get. Find your ideal Mercury Prop in 5 steps or less. search | FAQ | serial numbers than listed in these guides. If yours is a Mercury, Mariner, or Mercrusier, write down the Quicksilver prop number it finds for you in the 3 bladed aluminum prop. If it is a current number it will probably turn up in a listing somewhere, and you will be able to make an inference about what model it is. Yeah that's what I thought. the number indicates you have an original Merc prop. I recently added a Bobs Machine Shop 5" Jackplate. Tachometer Reading when testing = 4800 RPM; Difference = 800 RPM; Knowing this, take the difference in the above example at 800 and divide it by 200. Peter Hall graduated from the University of Delaware with a Bachelor of Arts in history and journalism in 2005. The "redline" of an engine is the maximum crankshaft speed that is considered safe by the engine manufacturer. The result is 4. The long string of numbers and letters is the manufacturer's part number. The closest SOLAS prop is a 14 x 21 (SOLAS #1511-145-21). Locating MerCruiser Serial Number Tags Engine Serial Number: The serial number tag is located near the starter, by the flywheel housing; or, on the rocker arm or flame arrestor cover. Ultimately you may need to accept a compromise or be prepared to swap propellers. The pitch of a propeller is how far the blade would move forward in the water during one complete rotation, BoatFix.com explains. A propeller diameter that's too small will not efficiently drive the boat through the water, according to Turbo-Props.com. There are no industrywide rules to interpret this number. Arranged by Horsepower. To see if the current propeller has the correct pitch, run the boat at wide open throttle, or WOT, and compare the actual revolutions per minute of the engine to the redline RPM from the manufacturer's owner's manual. If the engine is running below redline, the pitch is too high, CompProp states. Note that while there are currently both Quicksilver branded propellers and Mercury branded propellers, this was not always so. Transom Plates: The serial number tag is located on the inner transon plate inside the boat; or, on the upper swivel pin. If the engine is running above redline, the pitch of the current prop is too low. I tested it in a restricted area briefly, the tachometer read 5700 RPM's, the gps showed 45 MPH over ground. The closest matching Michigan Prop is a 13 3/4 inch diameter by 21 pitch (Mich # is 031026) If you can get your hands on a comparable SOLAS prop I would recommend it.