Mercury outboard compression specs. They are proven, reliable engines.
Mercury outboard compression specs The late 80’s 200 hp looper motors only had about 85-95 lbs when new. This engine has a multiport electronic fuel injection, mechanical and electric fuel pumps, water cooled with thermostat, and capacitor discharge ignition system. I had the dealership selling the 75hp do a compression test on the motor and they performed the test in front of me with the engine cold. What should this motor have for compression with these low hours, or am I being scammed and the motor really has 500 or more hours??? Thanks Dec 15, 2011 · Re: Compression question - 50hp 2 stroke Bond-O was the first one with the completely correct answer. When Oct 21, 2024 · 2013 Merc 15hp 4 stroke - Where can I find the spec on what the compression should be ? TIA Discussion about finding compression specifications for a 2013 Merc 15hp 4 stroke outboard motor Normal compression for a 2003 Mercury 125HP outboard typically ranges between 120-160 psi per cylinder. It includes specifications like horsepower, fuel tank capacity, oil injection tank specifications. "Check compression" is advice from people who haven't a clue what is causing ignition or fueling problems. 4 kPa (90 to 110 psi). Its better now but i have some hesitation at starting when cold. 4-Stroke. Dec 26, 2015 · 1995 Mercury 115 HP OB what is good compression? I m concidering buying a older boat it has a Merc. May 26, 2009 · You hear people talk about compression numbers. This engine has a batch fuel injection system, mechanical fuel pump of diaphragm or plunger type, electric start with bendix starter, and capacitor discharge ignition system. 95 in (75. It also provides instructions for routine maintenance like cowl removal, filling the oil injection system, checking fluid levels, lubricating pivot points. Mercury 20 ELPT Specifications The Mercury 20 ELPT is a 4-stroke 2-cylinder single overhead cam (SOHC) gasoline outboard engine with a maximum power of 20 hp (14. O. 40 in (61. Repeat for all holes. During a cold engine compression test, the cylinders both hit exactly the same at 100lbs. With its Mercury XRI 200 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing 94-2 194 Mercury 50 EFI Specifications The Mercury 50 EFI is a four-stroke four-cylinder overhead camshaft gasoline outboard engine. Mercury’s proprietary transient spark calibration, which boosts torque by as much as 7% during hole shot by optimizing spark timing and fueling, gets boats on plane quickly. 8 Your symptoms say nothing about compression. x 3. I would pronounce 90psi and even a healthy outboard and leave it alone. Mercury 200-hp V-6 EFI Outboard Specifications Propshaft Horsepower: 200-hp (149 kW) Max RPM (W. (89mm x 67mm) Fuel Induction System: Loop Charged Exhaust System: Through Prop Lubrication System: Single point variable ratio oil injection Cooling System: Water cooled Jul 2, 2015 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Is this acceptable? Motor has done 291hrs according to gauge. Mercury 60 EFI Specifications The Mercury 60 EFI is a four-stroke four-cylinder overhead camshaft gasoline outboard engine. Oct 31, 2006 · Re: Mercury 20 HP Compression I am always leary of any Merc that has been frozen up with any sort of rust. Also for: 90, 75, 115. Class-leading displacement and a proprietary 64-degree powerhead architecture are enhanced by the Mercury Racing Quad Cam Four Valve (QC4) design with double overhead camshafts and Aug 12, 2016 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Mercury 30 EFI Specifications The Mercury 30 EFI is a four-stroke three-cylinder overhead camshaft gasoline outboard engine. Top and middle 120 lbs, bottom 105lbs, walk away or see if some engine tuner brings it up. Aug 19, 2021 · Update: Conducted a compression test again this evening-using Bud's recommendation and two different testers. But now I'm reading up on it and wondering about that. This Mercury Mariner 115 HP Outboard service manual is your number one source for repair and service 3 cylinders tested 110 and 3 tested 115 on the compression test of this motor that’s on a boat I’m looking at. 9 Motors and PropsPorsche 911 T, Nissan Sentra, Dodge Charger Scat Pack, Kia Telluride - AutoGuide Show Ep. Shortly after a thorough decarb, it has 104 psi on the top cylinder, and 106-107 psi on the bottom cylinder, when taken on a warm engine. Here we give insight on how and why this should be conducted regularly. Aug 5, 2022 · He thought maybe a bad battery would cause low readings???? SHEESH!!!! Any motor getting a compression test HAS to have a fully charged full capacity battery or you will never get an accurate test period. 24 in (57. POWER DENSITY Power density is a key to high performance, and no marine engine delivers more punch in a lighter package than a Mercury Racing R-Series outboard. how will I know if the waterpumps impeller is still good? 3. Jun 29, 2012 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Jun 7, 2005 · Checked compression today on 2000 Merc EFI after engine running rough over the weekend. Nov 10, 2015 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Feb 28, 2016 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. ): 5000-5800 Cylinders/Configuration: 60 degree V-6 Displacement: 153 cu. some of the lower port timed inlines will record SLIGHTLY higher static compression just due to the port timing not bleeding off Dec 3, 2016 · Ask the experts on our Yamaha Outboard Forum for repair issues, diagnosing problems, links to diagrams, suggestions on buying parts and more. 0L, or a classic OMC, Johnson, Evinrude, or Yamaha, a compression test reveals how well each cylinder is sealing and helps guide decisions about rebuilds, tuning, and also fuel octane choice. Spark plug has metal residue on it. 00 in. 0l and was wondering what the compression should be i have about 90 psi is that good or to low? This document provides general specifications and maintenance instructions for Mercury outboard engines, including: - Engine specifications like horsepower, cylinder configuration, ignition type, and recommended fluids. I read somewhere that the plug wires need to be grounded when cranking ( by pull cord ) to prevent issues with the ignition system? Or is it OK to View and Download Mercury 50 4-Stroke manual online. View and Download Mercury 125 operation and maintenance manual online. 56 in (65. FWIW, your cylinders should compress within 10-15% of each other. The Born Again Boating American Fade Hooded Fishing Shirt! Look great while on land, on the water, or just hanging out with the seafoam faded long sleeve shirt that comes with an awesome blue Oct 21, 2014 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Mercury Mariner 115 HP Outboard Workshop Service Repair Manual Download This is the COMPLETE official full factory service repair manual for the Mercury Mariner 115 HP Outboard. 80 outboard motor pdf manual download. Apr 12, 2022 · Compression on a 9. I have a 95 Mariner 60 that has compression of 105 on top 100 on middle and We would like to show you a description here but the site won’t allow us. - Removal of cowl components and filling the oil injection system. This ensures maximum cylinder filling. I know that the factory service manual doesn't mention numbers. Feb 17, 2014 · Re: 2006 mercury 15hp compression question The compression test should be done with both plugs out of the motor and the plug wires grounded out to the block. Psi is irrelevant in a running engine, but should be over about 60psi if the test is done correctly in a rope start outboard. May 16, 2025 · Mercury’s exclusive Engine Guardian system senses any potential problems and instantly takes action to prevent engine or drive damages from low oil pressure, low drive lubricant or overheating. Document: - baads. What is manual specs on this engine ? One cylinder is 150 and top one is 136 is ut normal? Thanks again. Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds - BBC Sponsor Thermodude Member Join Recreational Outboards - With innovative technologies, simple maintenance and efficient performance, Mercury FourStroke outboards were engineered to elevate every moment on the water. Some times the rings may be stuck Mechanic's Assistant chat Customer: I am purchasing a 1990 Mercury 2 stroke outboard to replace my 40hp and the boat is rated for a 75hp. Never seen more than 130 in a 2 stroke cylinder in my experience. 9? I have a 1989 15hp Evinrude, same powerhead as 9. Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds - BBC Sponsor ZReel Member Join Date Nov Mercury Outboard Compression Forum Topics Mercury Outboard Parts Powerheads Mercury Propellers Mercury Manuals Oct 30, 2013 · Re: Mercury 40 HP 4 Cylinder 2-Stroke Compression Question That's good numbers. #3 and #4 are often the high ones (quite often higher than manual spec). Fx gasket on old repair slip could be Ex gasket or exhaust. Basically the compression is the same with all of em. 2. ): 5000-5600 Cylinders/Configuration: 60 degree V-6 Displacement: 153 cu. 96 Feb 23, 2024 · Looking at a 2005 Mercury 25 2 stroke this weekend. some of the lower port timed inlines will record SLIGHTLY higher static compression just due to the port timing not bleeding off Engine Man gives his full, in-depth analysis of the new Mercury Verado 350 and Mercury 400R outboard motors. Mercury XRI 200 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing Nov 6, 2011 · Re: Mercury 1993 25 hp 2 strokes compression REsult My gauge is bran new, but ivew paid it 30 bucks only. Low readings may indicate worn piston rings, damaged valves, or head gasket issues. Guy said that was fine. Obviously I’m gonna test it myself and see, but if it is that high…wondering if that’s a Mercury XR6 150 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing The Mercury- exclusive Advanced MidSection (AMS) and under-cowl noise management features set the standard for smooth, quiet marine propulsion. Engine Compression Engine compression should be checked with engine block warm, throttle shutter wide open, all spark plugs removed and using a fully charged battery. Nov 12, 2009 · I am looking at buying a merc outboard - 1997 250 hp EFI with an hour meter showing 178 hours. 6-litre. Jan 25, 2014 · Where do you guys obtain compression numbers for outboard 2 strokes and 4 strokes. Compression check shows 100,105,100,110,105,100. Obviously I’m gonna test it myself and see, but if it is that high…wondering if that’s a Apr 12, 2022 · Compression on a 9. A pioneering manufacturer of marine engines for over 70 years, as of 2010, Mercury is a division of Brunswick Corporation of Lake Forest, Illinois. Use a reliable compression gauge, test each cylinder, and compare results. These free online spec sheets provide many basic technical details to keep your Mercury Racing, ROS, and High-Performance outboard running at its peak. Suggestions?Could exhaust prblems cause low comp. The prop removed and the throttle in the FWD wide open position so the cylinder's get plenty of air to compress. For an 8 HP Mercury four stroke engine, normal compression typically ranges between 120-180 psi. Aug 9, 2024 · Explore the Mercury 60 HP boat motor’s impressive features, including fuel efficiency, smooth operating experience, and compatibility with various boat types. So plugged carbs, weakened fuel systems, cracked/deteriorated wiring and the electrical parts only live so long. A low compression reading may indicate worn piston rings or cylinder walls, while a high compression reading may indicate carbon buildup or a restricted exhaust system. Normal atmospheric pressure is 14. See full list on bornagainboating. Mar 6, 2023 · I paid to have a compression test done on the boat I just bought. (89mm x 67mm) Fuel Induction System: Loop Charged electronic fuel injection Exhaust System: Through Prop Lubrication System: Single point variable ratio oil injection Cooling Mercury 50 ELPT Specifications The Mercury 50 ELPT is a 4-stroke 4-cylinder OHC (overhead camshaft) gasoline outboard engine with a rated power of 50 hp (37. (3032cc) Bore & Stroke: 3. Compression on all 6 cylinders ranged from 100-110 on both testers. Mercury 225-hp V-6 EFI Outboard Specifications Propshaft Horsepower: 225-hp (168 kW) Max RPM (W. This compression ratio means that the outboard is designed to compress the fuel/air mixture at 6 times Jun 8, 2012 · Re: MERCURY 115 HP INLINE 6 CYLINDER COMPRESSION test readings, opinions please. The main thing you'll look for is consistency across the board, like no more than 10% variation. They can answer questions for any Yamaha outboard model or horsepower. in. 0 mm) and piston stroke is 2. And specific conditions under which those tests should be performed (see the FAQ Section, "Compression Testing"). Consistent readings around 140 psi on both cylinders indicate healthy compression, especially for low-hour engines. sometime in the late 70's Merc lowered the piston dome height on ALL inline 6's in an effort to make em not so prone to piston burning. The calibration of the gauge was verified within a couple of weeks before the reading was taken. What would be the best option for repair? View and Download Mercury 200 OptiMax manual online. 1977-1989 Mercury Mariner 2 Stroke Outboard Service Manual The document contains a list of engine specifications including horsepower, number of cylinders, fuel type, and model years for various outboard marine engines. Compression 135 PSI on 5 cylinders +\\- 5. This engine has been run at mostly higher Oct 9, 2013 · Re: force 120 hp compression test Thanks for response. If you have those 3 things and they’re working correctly, your engine will run. ): 5000-5800 Cylinders/Configuration: 60 degree V-6 Displacement: 185 cu. Sep 8, 2018 · The new 250R and 300R outboards boast class-leading 4. My question is: What should the compression number be? This engine is very clean with very minimal use We would like to show you a description here but the site won’t allow us. Do any of you people know what a newer motor compression numbers are #-o A newer 25hp Merc will have around 145 to 150 #'s. 125 outboard motor pdf manual download. Jan 20, 2005 · Re: What is good compression for a 9. Mercury 60 Bigfoot Specifications The Mercury 60 Bigfoot is a four-stroke four-cylinder overhead camshaft gasoline outboard engine. My question is Dec 8, 2008 · Basically the compression is the same with all of em. 200 OptiMax outboard motor pdf manual download. View and Download Mercury 80 owner's manual online. 5 to 758. We have 15 Mercury Optimax 115 Outboard Engine manuals available for free PDF download: Service Manual, Operation Maintenance Warranty Installation Manual, Operation Maintenance Installation Warranty Manual, Owner's Manual, Operation And Maintenance Manual, Manual, Manuam, Brochure & Specs, Installation Manual Mercury 150-hp XR-6 Classic Outboard Specifications Propshaft Horsepower: 150-hp (112 kW) Max RPM (W. what is good compression? 2. A complete disassembly is the only way to inspect all the bearings and replace what's damaged. Feb 6, 2008 · Re: mercury 200 optimax 2002 compression This is from the OEM service manual. Also for: 225 optimax. Checked fuel injector for that cylinder and it was dead. Regular maintenance STORE PRICING DOWNLOADABLE FORMS SPRING INBOARDS SPRING OUTBOARDS WINTER SPECIALS AREA INFO WEATHER & TIDES HARBORMASTERS Mercury 40 ELPT Specifications The Mercury 40 ELPT is a four-stroke three-cylinder overhead camshaft gasoline outboard engine. Even if you free it up, chances are there is some bearing damage, too. 7 is 132 psia or 118 psig, the latter being what your compression gauge reads. Ping, pre Jan 26, 2011 · I was wondering what is considered normal with regards to a compression check on a motor , and how much compression should a motor lose over time with normal running time . The document provides this This is a straight up step by step instruction video of how to do a compression test on an outboard motor. No other outboard goes from zero to wide-open throttle as fast as a Mercury Pro XS® engine. I would declare that engine healthy. Normal compression for all cylinders should be 620. Hundreds of pages allow you to print it out in its entirety or just the pages you need!! ALL STYLES COVERED. Most common problems they suffer from are from age. 115HP OB The seller has stated that the engine was serviced in 2011 I m unsure of what was done? Engine please provide tips to check it s condition like 1. I have purchased older Mercs & have had compression readings around those numbers also. 9 x 14. No outboard in the class offers more displacement than the Verado V-8 4. It also includes a table of contents that outlines the chapters and sections contained in the full manual, covering topics like safety, maintenance, fuel, ignition, timing, and Mercury 15 Pro kicker Specifications The Mercury 15 Prokicker is a four-stroke two-cylinder single overhead cam gasoline outboard engine. Anything between 100 and 140 is good but remember that actual reading is mostly gauge-dependant. 65 in. 7 psia at sea level. Low or uneven compression suggests worn piston rings, valves, or cylinder walls. Use a compression gauge to test each cylinder; if below 100 psi or varying widely, consider a professional inspection. Also for: 40 4-stroke, 60 4-stroke. The seller claims compression is 150 in both cylinders. Overview of Mercury Boat Motor 60 HP The Mercury Boat Motor 60 HP is a powerful and reliable outboard engine designed for various types of boats. Is there any concern regarding the ignition system when doing the test. Advanced features, custom graphics, & wide-range parts compatibility. Compression test need to be done with the throtal in the WOT position and the motor should be turned over 3 to 4 times on each cylender. 28 Number of Engine Horsepower Outboard 500 - 600hp 175 - 400hp 65 - 150hp 2. The Mercury 9. Every ounce is devoted to Wide Open exhilaration. Some of the 9. View and Download Mercury 75 service manual online. org Document: Nov 25, 2001 · What is the exceptable compression range for a 1998 90hp Mercury Outboard?<br /><br />Also, this engine has 3 carbs, looking from the port side I noticed at the top of each carb is an adjustment screw. It's the ratio between the volume when the piston is down and when the piston is up. 0 mm). That will materialize itself with time as the motor will slowly (sometimes quickly) shake and grind itself apart. (92mm x 76mm) Fuel Induction System: Loop Charged electronic fuel injection Exhaust System: Through Prop Lubrication System: Single point variable ratio oil injection Cooling May 19, 2011 · Re: 1984 merc 90hp 6cyl (tower of power) pro's and con's What specifically do you want to know? Mercury made this engine for a LONG time. I have a 1993 115 HP Mercury 4-cylinder 2-stroke outboard that has been sitting for about eight years. Jun 30, 2017 · The compression ratio in that engine is probably no more than 9:1. Jun 9, 2010 · i have an 87 mercruiser alpha one 3. Compression on 6th cylinder only 65 PSI. Apr 19, 2015 · The type and model is what matters in an outboard’s compression readings. (89mm x 67mm) Fuel Induction System: Loop Charged electronic fuel injection Exhaust System: Through Prop Lubrication System: Single point variable ratio oil injection Cooling We would like to show you a description here but the site won’t allow us. Still consider myself a " Marine Apprentice " after 47 years (learn something new every day). Dec 2, 2024 · Hi all, my 2005 90hp 2 stroke motor measures 105psi compression on all three cylinders (when cold). The engine cylinder bore is 2. This document provides general specifications and maintenance instructions for Mercury outboard engines. - Power trim system operation and fluid level checking. 5L, 3. I have been told that Mercury doesn't publish compression numbers. The two upper cylinders were 115psi and the lower cylinder was only 90psi. High octane gas actually burns slower than low octane, as it is a more articulated (branched) molecule. However, Mercury Marine themselves say that a variance of 15 psi is acceptable. Feb 25, 2021 · Hi, I have been trying to find out what compression I would expect from a 2004 Mercury 90hp 2 stroke , what is good what is bad pls? Jul 2, 2004 · Re: compression specs for 40hp force 1995 Plugs look the same dark and oily. Some outboard designs will read well into the mid hundreds. Consistent readings across all cylinders indicate good engine health. Still consider myself a " Marine Apprentice " after 48 years (learn something new every day). After verifying the Mariner 135 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing Dec 20, 2015 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. 63 in. 7 kW) at 5750 rpm. Also for: 30 efi, 25 efi jet. Founded by Cedarburg, Wisconsin engineer Carl Kiekhaefer in 1939, Mercury Marine produces inboard, outboard, sterndrive, tow-sport and jet engines for recreational and A pioneering manufacturer of marine engines for over 70 years, as of 2010, Mercury is a division of Brunswick Corporation of Lake Forest, Illinois. Mercury 60 ELPT Specifications The Mercury 60 ELPT is a 4-stroke 4-cylinder OHC (overhead camshaft) gasoline outboard engine with a rated power of 60 hp (44. Engine ran lean. Jun 6, 2011 · Re: What should the compression be on my merc110=9. We would like to show you a description here but the site won’t allow us. #3 is a bit low, go to a Yamaha powersports dealer and get a jug of Ring-Free+, put a couple of ounces or so in a spray bottle, remove the plugs, and spray liberally in each bore. Jul 28, 2016 · Hello all, I have a new-to-me 2004 25 hp 2 stroke Mercury engine that seems to start and run well. Most small horsepower (up to 25 hp) two-cycle outboards built prior to the 1960s had a compression ratio of about 6 to 1. 9 HP outboard engine is a two cylinder four-stroke marine engine that delivers smooth, quiet, fuel efficient power. Feb 24, 2015 · I'm looking at buying a boat that has '91 Mercury 75 hp on it , it's just a bit out of the 10% rule on compression . That seems a little high to me. Mercury 175-hp V-6 EFI Outboard Specifications Propshaft Horsepower: 175-hp (131 kW) Max RPM (W. A little Performance Outboards - For competitive tournament anglers or boaters who crave speed. 25 EFI outboard motor pdf manual download. Sep 11, 2012 · Hey everybody, I'm looking at buying a used boat with a 1998 or 1999 125 hp MERCURY carbureted 2-stroke 4 cylinder outboard that I believe has the '2+2 feature' ( where it only runs on two cylinders at low idle). Have run on the lake with only minor problems flooding somewhat easily. 7 kW) at 6200 rpm. This is a mujst do when buying a used boat or outboard motor of any kind. Cylinders should not vary more than 103. Cheers. Mar 22, 2021 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. Ideal for high-performance Nov 24, 2019 · Looking at buying a ranger with a 2013 Mercury pro XS 150 2 stroke and I am not sure where to find the compression numbers. 00:1 Ratio) . 4L, 2. The seller has had the engine professionally maintained for years and has had a Find your new standard of performance with Mercury Racing's 400R outboard engine. The pull rope should be very easy to pull when done this way. SPECIFICATIONS – 350 VERADO[BACK TO MOTORS] Jan 20, 2014 · Re: compression test on 8 hp O/B Because of rope start compression numbers can vary all over the place. There is a nub on the camshaft that just cracks the exhaust valve open on the compression stroke. Also for: 75 marathon, 75 sea pro, 115, 125, 65/80 jet, 90, 100. You can't believe everything you read on the For accurate compression readings on a Mercury 225HP 2-stroke, warm the engine fully and hold the throttle wide open. Gear Ratio (Standard) . Everyone I've talked to agrees that these motors register lower on a compression gauge than a conventional outboard due to their lower compression ratio. 00:1 Gear Ratio (High Altitude) . T. Founded by Cedarburg, Wisconsin engineer Carl Kiekhaefer in 1939, Mercury Marine produces inboard, outboard, sterndrive, tow-sport and jet engines for recreational and FourStroke - A Mercury 75 - 150hp FourStroke outboard motor features an efficient, lightweight design that ensures maximum power, and makes great days on the water possible. May 11, 2025 · Whether you’re working on a Mercury 2. Looks like those readings should be 100 psi or better. 9, with about 600 hours on it. Yes there is a decompressor to allow for easier starting. However, a healthy compression reading for a 2-stroke outboard engine is typically around 90-110 psi. Ill try with another gauge from the job if thread are the same. 4 kPa (15 psi) between one May 1, 2016 · I have a 2005 merc 50 HP 2 cycle and mine are between 114 and 118 which I thought were low but I have a good friend in another state that is a mercury repairman and he told me this is fine. Mercury EFI 175 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing Jun 29, 2007 · Re: 75hp mercury what is too low of compression? A fw years ago my son's Merc 115 HP inline 6 had a scored cylinder; we got 118-120 PSI on the 5 good cylinders. Yesterday engine start with 8 pull with choe ajustement between pulls, but when it fires he start first time. x 2. Aug 12, 2004 · General Q & A - Compression numbers for a 60HP Mercury Bigfoot? - My In-Laws are looking at a pontoon boat that has a 2000 60 HP Mercury Bigfoot outboard and the dealer is going to do a compression check in front of them. Learn about its engine displacement, compression ratio, and fuel type. 9hp outboard motor is lightweight, compact, and powerful making it a great choice for long shaft jon boats, skiffs, and small pontoons as well as auxiliary power for your sailboat. Manuals and User Guides for Mercury Optimax 115 Outboard Engine. Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds - BBC Sponsor Anthonysjo Member Join We would like to show you a description here but the site won’t allow us. 5 in. There are SMALL differences in compression based on several factors: 1. Those 3 things, in order of importance, are compression, spark, and fuel. Jun 5, 2024 · It's 90-110 psi, max variance of 15 psi. Scroll our spec sheets for Mercury Racing outboards to find key tech information on engine displacement, weight, spark plugs, timing settings, oil and fuel capacities, and recommended fluids for optimal performance. Jun 28, 2011 · This is a question for any Mercury mechanics or anyone else in the know. 50 4-Stroke outboard motor pdf manual download. So 6:1 comp ratio and 88 psi is a good and valid value for MANY or even most low horsepower models but there are exceptions and variations to every general rule. (2507cc) Bore & Stroke: 3. The Optimax motor sounds weird when starting anyway and I have had a few customers say its still not cranking over like it should even after they installed a new battery. 30:1 Number of Teeth (Forward Gear, 2. May 20, 2010 · Re: what is compression on mercury optimax 175 If my memory serves me right it should be between 110# and 130# for the motor to perform with the power it should. I tested the compression and found it to be 145 lbs on cylinders 1, 2, and 3, and 140 lbs on cylinder 4. Motor is a 2017 model with 148 hours…. - Tilt angle adjustment for models with and without Mar 21, 2010 · Can anyone give me the compression specs for a 1999 Mercury 25hp 2 stroke motor? View and Download Mercury 25 EFI service manual online. 5’s had 65-75 lbs when new. . The results were 85, 90, 90, 90, 95, 95. should some lower units oil be drained and inspescted We would like to show you a description here but the site won’t allow us. Also for: 115, 100, 80 efi, 115 efi, 100 efi. If the readings are more than 10% difference then the motor Feb 17, 2016 · What should the compression be on a 1999 125 Mercury? SPECIFICATIONS – 300 VERADO[BACK TO MOTORS] Mercury EFI 150 Hp specs: Rated power, bore and stroke, fuel system, cylinder block, piston and piston rings, gear housing Nov 2, 2025 · The portable Mercury 9. May 24, 2018 · I am going to do a cylinder compression test on my 1970 110 merc outboard. This applies to a Mercury 200 efi 2002 that I have. Jun 2, 2014 · Dual Mercury Master Technician - for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC. If a motor has 110 psi on all six cylinders 3 years ago, with normal use ( SAY 50 hours a year) what should be the pressure 3 years later ( 100-95??). com Aug 2, 2014 · 42 psi +/- 14 psi on a static compression test. 75 outboard motor pdf manual download. Can anybody help? A compression check will tell a lot about the health of an outboard engine. The higher the compression, the slower the fuel needs to burn, and so you need higher octane. Oct 13, 2023 · The compression psi of a 2-stroke outboard engine can vary depending on the specific model and condition of the engine. 6L displacement, resulting in 40% more bottom-end torque. Outboards require 3 basic things, and this instructional could well serve as a primer for things you may want to check for when buying a used outboard. 0L, 2. 5 - 60hp MerCruiser 200hp 250hp 300hp 350hp 380hp 430hp 520hp Racing Outboard 300hp 400hp 450hp 500hp Engine Model Outboard - 115 FourStroke 500R FourStroke Apr 11, 2010 · Re: 1994 Mercury 200 hp compression check Remove all plugs, flip the kill swith, open the throttle, screw the gauge in hole #1 and crank 3-4 sec. Customer: My 90 hp 2-stroke engine has a compression reading of 110 psi on cylinder #1, 110 psi on cylinder #2, and 40 psi on cylinder #3. Dec 12, 2013 · Re: 1999 90 hp 2 stroke compression numbers, Readings differ from gauge to gauge but it is impossible for 3 cylinders to go bad the same amount at the same time. They are proven, reliable engines. Not necessarily the hp or size. Jul 31, 2003 · 10% is the figure I normally use for a compression test be it for cars or boats. ieqtoy cspo zemzh nlya hrvzo tkfa okgcvnh jvgu zvfma jkouzazf kpzo hebfutex qlms jmwuu rmxdpj