2 stroke mercury outboard compression chart

BUY A COMPRESSION TESTER HERE http://www.amazon.com/gp/product/B004K2FSXI/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B004K2FSXI&linkCode=as2...

In the early 1970's, when you could still get good gasoline, outboard compression in the 180-190 psi range was common. If your 65 hp Johnson is running in the 100-150 psi range, this would be acceptable, and the engine should still perform well on todays fuel. The important thing to note with compression readings however, is that the difference ...Tips for Repowering Older Boats. Tips for repowering older boats: Scuppers above the waterline ensure drainage. Wide chines are one way to help float heavier power. Brackets with more immersion provide more buoyancy. Boating Magazine. Also, four-strokes are losing weight, which should help when repowering an older legacy boat.Verado 135-200 4-Cylinder. 835257K10. Mercury / Mariner 40-60 HP BigFoot and 90-115 HP FourStroke Outboards. 835257K9. Mercury 225 EFI FourStroke Outboards. 835274K1. MerCruiser 400 HP+ Bravo One Sterndrives (1" Solid Hub) 835258K2. Mercury V6 (1.00") used with Surfacing Propellers; Rev 4, Trophy Plus, Fury, Tempest Plus.This in-line 3-cylinder outboard provide all of the extra features you want and need without compromising Tohatsu's well-known ... Tohatsu 2-stroke benefits. Excellent reliability with proven 2-stroke technology; Simple in design; Fuel & oil automixing for optimum lubrication* Easy operation and handling. Loop charged induction for smooth ...Place your engine’s throttle in the neutral position. 4. May sure the key is not in the ignition. 5. Using your torque wrench with a spark plug socket, carefully remove each plug. 6. NGK spark plugs come pre-gapped. If you would like to check the gap, you can do so with a gap gauge.The 200 HP from Mercury comes as a 3.4 V6 and the Pro XS version is the 4.6 V8, making for a really powerful albeit heavy 200 HP outboard. Also, this means there are several SKU's in the 200 range because the 200 Pro XS is offered with a 4.8" (1.85) gear case or Torque Master (1.75).

On a 4 stroke engine, most mechanics and dealers will perform a leak down test, to see how much pressure escapes over a set period of time. On a 2 stroke engine, a …MERCURY OUTBOARD APPLICATION CHARTS Diameter Pitch Material Blades LH Rotation RH Rotation Model Application ... Mercury/Mariner 8/9.9 Hp (4‑Stroke) Outboard MERCURY PROPELLER APPLICATION . 9.9 HP Bigfoot Model Year 2005 and newer 9.9HP Pro Kicker 15/20 HP 2008 and newerJan 4, 2008. #3. Re: 1998 EFI 225 Compression. This is directly from the OEM service manual. COMPRESSION All Models - Using a fully charged battery, throttle shutters wide open and cylinder block warm. 110 - 135 psi. (753.3 - 924.5 kPa) Variance between cylinders should not exceed 15 psi (102.7 kPa) D.Re: 2002 Mercury 150Hp xr6 Compression and overall reliability of outboard From Mercury Service manual COMPRESSION All Models – Using a fully charged battery, throttle shutters wide open and cylinder block warm 110 – 135 psi (753.3 – 924.5 kPa) Variance between cylinders should not exceed 15 psi (102.7 kPa)If it is running good give it a good decarb and do the compression test again. Get a can of seafoam spray and bring it up to operating temp and at a high idle spray the seafoam in the carbs evenly until it starts smoking real good and quickly shut it down. Wait 1/2 an hour and then start it and run WOT for about 20 minutes.

Mercury OptiMax 200 is a two-stroke DFI (Direct Fuel Injection) engine. It is a sturdy, reliable engine made of strong alloys. It has been providing the best quality for a decade now. Mercury started making the OptiMax engines in 1995. The 200 has a V-6 3.0L engine. The engine's best specification is its hole-shot acceleration. This allows a ...Optimax Pro XS 250 HP. HP/kW 250 / 184. Full throttle RPM 5500-6000. Cylinder Configuration V-6. Displacement (L) 3.0. Fuel Induction System 2-Stage Direct Fuel Injection (DFI) Alternator Amp 60 amp / 756 watt (Belt-Driven) Gearcase Ratio 1.75:1. Steering Big Tiller Compatible.Apr 30, 2020 · I love my Mercury 4 stroke EFI, nice and quiet and don’t have to mess with a choke. I’m betting your manual says your motor is designed to be used with fuel with 10% ethonol. Jeremy. Participant. Richland County, WI. Posts: 653. May 1, 2020 at 1:36 pm #1939180. Mercury 250R / ProXS The 4.6 V8 platform is relatively new and is quickly showing to be a really flexible engine for Mercury Outboards. For the 250 HP range there are multiple engines available; the Verado 250, Sea Pro, ProXS, Racing 250R, and standard four stroke, all based on the 4.6L V8. There are a few different features on each to ...

Uva health portal.

The 2 stroke, 25 hp Mercury outboard requires a 50:1 ratio, this is roughly one pint of 2 cycle oil, to six gallons of fuel.SmartCraft Connect is compatible with all SmartCraft-capable Mercury outboards (2004 and newer, 40hp and above; 2022 and newer, 25hp and above). Learn More. Troll Control Troll Control eases the critical task of precisely maintaining a targeted trolling speed by locking in the engine rpm. Once set, adjustments can be made in 10-rpm increments ...The most likely reason why a two-stroke engine has lost compression is an issue with the piston or piston rings. The piston is the part of the engine that creates the compression needed to run. If there is a crack in the piston, air can escape and cause a lack of compression. This article will discuss the steps necessary to figure out why your ...MERCURY Outboard 2.5-HP Thru 150-HP PRICES: 2023- PY. Prices Include: 3-Year Mercury Marine Warranty, Plus Additional 2-Year MPP Gold Warranty; Total 5-Year Warranty, Pre-Delivery Inspection & 1st Hour of Engine Break-in and Grow Boating Fee. Per Mercury Marine Policy, we can NOT Ship Outboard Engines OVER 25-HP.

It's a substantial 11.5kg skinnier than the Yamaha F60. Interestingly, the Tohatsu 60hp four-stroke is also 15 per cent lighter than the old 60hp Tohatsu two-stroke outboard engine, which shows how far engine makers have cut weight and boosted four-stroke outboard engine performance.Mercury 115 EFI 4-Stroke User Manual (62 pages) 75/90/115 EFI 4-Stroke. Brand: Mercury | Category: Outboard Motor | Size: 2.54 MB. Table of Contents.If your fuel pump is whining or squealing, it is typically one of two reasons. First, the pump might be starving for fuel. Fuel lubricates fuel pumps; if your fuel filter is blocked or clogged, it may be prohibiting gas from getting to the fuel pump. In this case, the problem is likely a blocked fuel filter, not necessarily a bad pump.Oct 30, 2013 · 330. Oct 31, 2013. #4. Re: Mercury 40 HP 4 Cylinder 2-Stroke Compression Question. That's good numbers. #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. Crank the engine for a couple of seconds, wait overnight, and ... Optimax Pro XS 250 HP. HP/kW 250 / 184. Full throttle RPM 5500-6000. Cylinder Configuration V-6. Displacement (L) 3.0. Fuel Induction System 2-Stage Direct Fuel Injection (DFI) Alternator Amp 60 amp / 756 watt (Belt-Driven) Gearcase Ratio 1.75:1. Steering Big Tiller Compatible.Outboard Engine DVA CHARTS ... Mercury Yamaha CDI Part # 961-0003 Rev Q 2/8/2012 TECH SUPPORT 1.866.423.4832 CUSTOMER SERVICE 1.800.467.3371 www.cdielectronics.com. All rihts reserved Reroduction or use o content in any manner ithout eress ritten ermission y CDI Electronics Inc is rohiited CDI Part Rev //The high-power four stroke models F250, F225 and F200 are masterpieces of Yamaha outboard technology. Skip to Main Contents. Outboards Home; News; Japanese Site; Select Region; Top; Products. Products Top; Four Stroke. 450-375ps. 300-250ps. 250-200ps. 200-115ps. 100-75ps. 70-2.5ps. Two Stroke ...Oct 31, 2006 · Nov 1, 2006. #5. Re: Mercury 20 HP Compression. Compressions should be higher than that. aprox 120-140. Unfortunatly if the bore is scored may as well use it as a artifitial reef. These engines have a chrome bore. Precision engine rebuild will be the likely cost effective repair. Jan 6, 2006 · Apr 9, 2005. Messages. 80. Jan 7, 2006. #5. Re: What should compression be at for a ELPTO 90HP - 2005. 90 to 115 psi for those engines is just fine . The main thing is their within ( and here is big debate lies )15% of each other.Some say psi and not % and some say no more the 10 psi or %. P. Hi I have a 1999 Merc 2 Stroke 9.9HP that was under river water for 7 days. It was not running when it went under. ... Mercury & Mariner Outboards . Poor Compression 9.9HP Merc 2 Stroke. Thread starter Luv_Fishin; Start date Aug 25, 2010; L. Luv_Fishin Recruit ... Poor Compression 9.9HP Merc 2 Stroke Ahoy, Rick.1987 1993 Mercury Mariner Outboard 2 Stroke 70 75 80 90 100 115 Hp Motors Service Repair Manual Pdf Preview Highly Detailed Fsm Perfect For The Diy ... 2. Install compression gauge in spark plug ...Your Mercury serial number is the key to finding the correct parts for your motor. Mercury serial numbers are usually found on an ID tag on the engine mounting bracket. Mercury Parts Inventory. MarineEngine.com keeps thousands of Mercury parts in stock. We offer the largest selection of old stock, Quicksilver original parts and quality discount ...

XL. G303046 - UP. 135. 1996. XL. G303046 - UP. MODEL YEAR CHART FOR MERCURY OUTBOARDS MODELS 115 HP - 150 HP.

Place your engine’s throttle in the neutral position. 4. May sure the key is not in the ignition. 5. Using your torque wrench with a spark plug socket, carefully remove each plug. 6. NGK spark plugs come pre-gapped. If you would like to check the gap, you can do so with a gap gauge.07-04-2005, 06:52 PM. I have a 2001 Yamaha 200HP HPDI with 700 hours. I did a compression check and my lowest cylinder reads 100 psi and the highest being 107 psi. When I perform the compression check all spark plugs are removed but the throttle is at fast idle (due to the starter can't be engaged with the motor in gear and full throttle).Attach the pressure gauge hose to the outlet. Seal the inlet firmly with your thumb. Pump the pressure gauge a few times. Release your thumb. If the pressure releases, it’s a clear sign that the inlet is allowing pressure to escape in either direction and the valves aren’t in proper working condition.The WOT test is done in three simple steps: 1. Find out your outboard or sterndrive's WOT rating. 2. Run your boat at WOT. 3. Replace the propeller with a higher or lower pitch prop. To get the most accurate result from the WOT RPM test, there are a few things you need to do to ensure the data from the wide open throttle test is as precise as ...Mercury Mariner Outboard Forum . What is the compression pressure on a 40hp 2 ... What should I expect for PSI on a compression check on a 40 hp 2 stroke …Attach the pressure gauge hose to the outlet. Seal the inlet firmly with your thumb. Pump the pressure gauge a few times. Release your thumb. If the pressure releases, it's a clear sign that the inlet is allowing pressure to escape in either direction and the valves aren't in proper working condition.Of course, the 3/8″ fuel line will work for any of the outboards. But most smaller outboards have fittings or quick connects on them that are set for a 5/16″ hose. It's basically the standard hose for the smaller engines. Like we said in the beginning, the 3/8″ line is required on anything that is larger than a 115 HP engine.From their sensationally powerful Verado 300-hp, all the way down to their simple 2.5-hp portable, every Mercury four-stroke is smoother, cleaner, quieter, and more dependable than any competitor's engine. Plus, much like their two-strokes, Mercury four-strokes have never lacked in the power department. Two-Stroke Piston upstroke.Which is better 2 stroke or 4 stroke? Today we look into some of the pros and cons of the 2 stroke engines and the 4 stroke outboard engines. 2 strokes are f...The two stroke outboards are lightweight and compact yet deliver high power output. The engine structure is relatively simple and maintenance is exceedingly easy. Although we have lineup of four strokes, we also offer an extensive two stroke lineup to meet diverse global needs. 200-60ps. 40-25ps. 15-2ps.

Micah bigelow obituary.

My. unm.

gboy99. So maybe I have too much time on my hands but I was looking at the service book of my 2011 Mercury 75Hp 2 stroke outboard and I noticed the last compression reading (taken last week) for cylinder 3 was 130psi. From new it was 140psi. Below are the readings taken during scheduled services since new.Apr 10, 2010. #2. 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. Repeat for all holes. Anything between 100 and 140 is good but remember that actual reading is mostly gauge-dependant. The main thing you'll look for is consistency across the board ...On a 4 stroke engine, most mechanics and dealers will perform a leak down test, to see how much pressure escapes over a set period of time. On a 2 stroke engine, a …XL. G303046 - UP. 135. 1996. XL. G303046 - UP. MODEL YEAR CHART FOR MERCURY OUTBOARDS MODELS 115 HP - 150 HP.Replace the plugs and let it sit for a few days. Start the motor to burn it off then re-do the compression test. That might free up the rings and get you some compression. Option 2: Get a 1 gallon jug, mix a gallon of gas/oil to ratio in the jug. Pour a enitre can of Seafoam in there.Mercury Outboard Compression Nissan Outboard Compression Suzuki Outboard Compression Tohatsu Outboard Compression Yamaha Outboard Compression Related Links Enter the Forums Evinrude Forum Directory ... Stroke Switch Tach Tank Tell Tale Test Troubleshooting Used Water Pump Wiring Evinrude Outboards by Horsepower 2 HP 3 HP 4 HP 5 HP 6 HP 8 HP 9.5 ...Mercury Outboards. Horsepowers by Year ... 3.5ML 3.6M 3.6ML 300E 300ELPT 300M 300S 300XLPT 30E 4-Stroke 30E EFI 30E EFI 4-Stroke 30EHO 30EL 4-Stroke 30EL EFI 30EL EFI ...Converting to the U.S. System How do you calculate the gas to oil mixture for a two-stroke boat motor in the United States? 1 U.S. Gallon (Gal) = 4 quarts (qt) = 128 fluid ounces (fl oz) = 3.785 Litres (L) For a 50:1 ratio each gallon of gas requires 2.6 oz of two-stroke engine oil. Here is a quick chart for a 50:1 ratioJan 6, 2006 · Apr 9, 2005. Messages. 80. Jan 7, 2006. #5. Re: What should compression be at for a ELPTO 90HP - 2005. 90 to 115 psi for those engines is just fine . The main thing is their within ( and here is big debate lies )15% of each other.Some say psi and not % and some say no more the 10 psi or %. P. The 30-plus Yamaha four-stroke outboard engine range kicks off with a 2.5hp portable outboard and tops out with an apex predator, the 425hp V8 XT Offshore 5.6-litre V8 launched late in 2018. The engines come in different performance bands, starting with the 2.5hp to 70hp models, the 115hp to 200hp in-line four-cylinder models, the …Page 12 SPECIFICATIONS Propeller Information Charts Mercury/Mariner 4 (4-Stroke) Wide ... GENERAL INFORMATION Compression Check 1. Remove spark plugs. 2. Install compression gauge in spark plug hole. ... 25. Prime the oil pump by pouring approximately 1 fl oz. (30 ml) of engine oil into the oil pump inlet side. 4-Stroke Outboard Oil (92 ... ….

Here are 10 reasons and fixes to help prevent lack of fuel to a 2-stroke engine. 1. Mixture Screws. The first thing to check before anything else is the mixture screws. The fuel air mixture screws on the side of the carburettor are marked H for High for the engines high speed adjustments and the L means Low for the engines low speed adjustments.There is NO serial-to-year cross-reference chart for 1997 and later motors. Mercury has never really used model years for much of anything other than "sales tools" in dealerships. We WILL need your serial number to look up correct parts. Arranged by Horsepower. 4 - 6 HP 7.5 - 9.9 HP 15 - 25 HP 30 - 40 HP (2-CYL) 40 (4-CYL) - 50 HPThe 60hp Mercury four stroke Big Foot has the same powerhead as its 50hp Mercury 50 counterpart and uses the same pistons and conrods from this engine and the F40. The simple SOHC powerhead is a non-interference type where the valves won't contact the piston crowns should the camshaft belt break. Because of the SOHC design, valve clearance ...Performing tests on ignition components requires that you have the proper equipment to do so. This chart assumes you have the adequate testing equipment to diagnose ignition problems. Understanding this chart: Example: Grn = Green Wht/Grn = White/Green Stripe. "Wire to wire" means take measurement between those colors of wires on the component.And when a head gasket wears out, it automatically causes poor compression in the cylinder. 4. Carbon-Clogged Piston Rings. The clogging of piston rings with carbon is another common cause of a low compression reading in your engine. Plus, the outboard motor or your boat goes through a constant combustion cycle.Mercury DVA (Peak Reading) Voltage and Resistance Chart HP Year Serial# Ignition Part Number Stator Trigger Read Ohms DVA Low SpdHigh Spd High Spd Low Spd High Spd Read Ohms DVA 4 1 CYL 1972-1975 3296137-A855096 336-4516 Green to Engine Ground (DVA only) 2100-2300 (a) 170-190 (b) 180-400V Points Brown & White N/A N/A 4-20 2 …Nov 12, 2009 · Nov 11, 2009. #1. I am looking at buying a merc outboard - 1997 250 hp EFI with an hour meter showing 178 hours. Compression check shows 100,105,100,110,105,100. 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??? HYDRAULIC SYSTEM TROUBLESHOOTING CONDITION OF TRIM SYSTEM PROBLEM Trim motor runs;... View and Download Mercury 225 EFI service manual online. 3.0 Litre Work, Electronic Fuel Injection. 225 EFI engine pdf manual download. Also for: 250 efi, 3 liter work 225 efi, 3 liter work 250 efi.This 90hp 4-stroke EFI features the same valve train architecture as Verado. The basis of the engine is a four-in-line, 1732cc powerhead, - the largest displacement engine in the 90hp 4-stroke class - dual overhead cam engine that provides excellent low-end power. It is also the heaviest of all the 90hp engines we tested, at 181kg. 2 stroke mercury outboard compression chart, XL. G303046 - UP. 135. 1996. XL. G303046 - UP. MODEL YEAR CHART FOR MERCURY OUTBOARDS MODELS 115 HP - 150 HP., Outboard Motor Mercury 225 HP Installation Manual. 4-stroke (17 pages) Outboard Motor Mercury 25 EFI Service Manual. (540 pages) Outboard Motor Mercury 25 EFI FourStroke User Manual. (161 pages) Outboard Motor Mercury Optimax User Manual. Gasoline motor optimax (121 pages) Outboard Motor Mercury 40 Service Manual., A two-stroke cylinder head only has two parts, so no big deal to go to a v-block and have two cylinder heads instead of one. The old Mercury 125-HP 2+2 has no balance shafts, large displacement, and plenty of vibration. That is why they limit the red line to a very curiously low 5,250-RPM. , Nov 25, 2001 · 8,217. Nov 25, 2001. #2. Re: Compression for 90 hp Mercury. You have a stuck needle valve in the carb. This needle valve is pushed up by the float,to shut off the fuel flow when the bowl is full. The carb must be removed,dssassemble at the float,needle removed and cleaned (or replaced if bad),and the carb re-assembled. , FORCE TORQUE SPECS. SPECIAL SETTINGS FOR 3-4 CYLINDER 1996-UP MODELS. 1995 & Older HERE. CYLINDER HEAD BOLTS THRU SERIAL # 0E138599. 225 IN. LBS. CYLINDER HEAD BOLTS FROM SERIAL # 0E138600. 120 IN. LBS. + 90° (1/4 TURN) FINAL. CYLINDER HEAD COVER BOLTS. 70 IN. LBS., THRU 1996. Mercury did not publish model year information for 1997 & newer outboards. The year is now normally noted on the serial number sticker. NOTE: Mercury DOES NOT Use Model Years For Parts Lookup. This Chart Is For. Reference Only, Since Many Aftermarket Parts Manufacturers DO List Parts By Year. A "0" in front of the serial …, Data on the Mercury 2-stroke range has been retained on this page as a reference source: this reflects 2006 production, after the withdrawal of carburetted V-6 models. ... These ultra-smooth three-cylinder outboards with big-capacity 967cc powerheads will provide you with even better acceleration and higher top speed to take you wherever you ..., Mercury Outboards Product Handbook - Mercury Marine. This pdf document provides detailed information on the features, specifications, and benefits of Mercury outboards, the world's leading marine engines. Learn how to choose the right outboard for your boat, and discover the advantages of Mercury's innovative technologies and unmatched reliability., MODEL YEAR CHART. THRU 1996. Mercury did not publish model year information for 1997 & newer outboards. The year is now normally noted on the serial number sticker. NOTE: Mercury DOES NOT Use Model Years For Parts Lookup. This Chart Is For. Reference Only, Since Many Aftermarket Parts Manufacturers DO List Parts By Year. , Mercury Outboards Product Handbook - Mercury Marine. This pdf document provides detailed information on the features, specifications, and benefits of Mercury outboards, the world's leading marine engines. Learn how to choose the right outboard for your boat, and discover the advantages of Mercury's innovative technologies and unmatched reliability., I've found a sweet looking 2001 ELPTO Mercury 90 2-stroke that appears to be in good shape, used mostly in fresh water and well maintained. The seller claims it's had a recent water pump replacement, T-stat, leg oil, and fuel filters. Compression is said to be even on all three at 120psi., Re: 99 115 2-stroke vibrates/runs rough midrange. lugnutz426 said: This Started The End Of Last Season. Shakes And Runs Rough Off Idle And Up Worst At Around 3000 Rpm. Starts And Idles Okay. Will Run 5300 Rpm. Smoother At High Rpm. Prop Good, Carbs Rebuilt, Fuel Pump Rebuilt. 140-145 Compression In All 4., Mercury 250R / ProXS The 4.6 V8 platform is relatively new and is quickly showing to be a really flexible engine for Mercury Outboards. For the 250 HP range there are multiple engines available; the Verado 250, Sea Pro, ProXS, Racing 250R, and standard four stroke, all based on the 4.6L V8. There are a few different features on each to ..., Summary of Contents for Mercury 6. Page 1 6/8/9.9/10/15 Starting Model Year 1986 Serial Number 0A197112 and Up (USA) 09503295 and Up (Belgium) Page 2 Hazards or unsafe practices which could result in minor personal injury or product or property damage. Notice to Users of This Manual This service manual has been written and published by the ..., Messages. 4,845. Mar 10, 2011. #2. Re: How much does my 50 hp merc weigh? Depending on the model number and whether standard gear casing or Bigfoot, from the manual Specs section, 205 to 219lbs. To get an eyelet or not, how much is the engine worth to you? Gerry., A leading name in marine engines, Mercury is recognized for producing top-quality outboard motors as well as the MerCruiser line of inboard engines. Founded in 1939 by the talented engineer-businessman Carl Kiekhaefer, the Mercury brand of boating engines are found as factory equipment with many watercraft manufacturers., Mercury EFI TwoStroke deliver fast acceleration and smooth, reliable operation. Plus with the added power of 2.5 litre 'big block' engines, you know you have what it takes to move larger vessels with ease. The powerhead design is a slim 60° V6 that is ideal for twin-rig installations. Propshaft Rated Horsepower. 200hp (149kw), Like other 115hp performance motors, the 115 Pro XS is available in 20-inch and 25-inch shaft lengths, but the available Command Thrust gearcase is a feature no other outboard brand offers. The 4.9-inch-diameter Command Thrust case accommodates Merc's top performance props up to 16-inches in diameter. More blade area and the lift provided by ..., How to Compression Test on Mercury 2-Stroke Outboard Engine November 17, 2016 Repair Manual Do-It-Yourself Outboard Repair Guides 2 Its highly recommended to always use a outboard repair manual for your specific year and model outboard engine when preforming a cylinder compression test on your motor., 1987 1993 Mercury Mariner Outboard 2 Stroke 70 75 80 90 100 115 Hp Motors Service Repair Manual Pdf Preview Highly Detailed Fsm Perfect For The Diy ... 2. Install compression gauge in spark plug ..., Re: MERCURY 115 HP INLINE 6 CYLINDER COMPRESSION test readings, opinions please. 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. From the readings posted at 3 revs everything looks good as they are all lest that 10 percent overall diffrence., Embrace Possibility. Mercury FourStroke outboard motors are incredibly powerful and efficient, and they feature a wide range of applications. Crafted for less weight and high displacement, they generate abundant torque and immediate power. And because they don’t have to work as hard as heavier engines or those with lower displacement, they make …, Oct 9, 2020 · The most likely reason why a two-stroke engine has lost compression is an issue with the piston or piston rings. The piston is the part of the engine that creates the compression needed to run. If there is a crack in the piston, air can escape and cause a lack of compression. This article will discuss the steps necessary to figure out why your ... , 40ELPTO. This 40 horsepower Mercury outboard, manufactured in 1997, is a saltwater model. The engine weight is recorded at 177 lbs. This is a 4 cylinder model. The displacement for the pistons is 43.9. The bore for this outboard is 2.56 inches and the stroke is 2.13 inches. This engine has power steering and a electric-type starter., Fuel System Issues. One of the most common ways your Yamaha outboard motor will break down is a fuel system failure. Whether you're experiencing an intermittent bog down, poor performance, or complete engine failure, your fuel system is a common culprit. Ethanol gasoline: Only use premium low-ethanol gasoline for your Yamaha outboard motor., Handy Quicksilver oil change kits are available for many Mercury® MerCruiser® sterndrive and inboard engines, four-stroke Mercury outboards from 15hp to 400hp, many Yamaha® 30hp to 300hp outboards, and engines from Volvo Penta® and other popular brands. Each kit includes Quicksilver 25W-40 or 10W-30 Marine Engine Oil, an oil filter and instructions …, 8,217. Nov 25, 2001. #2. Re: Compression for 90 hp Mercury. You have a stuck needle valve in the carb. This needle valve is pushed up by the float,to shut off the fuel flow when the bowl is full. The carb must be removed,dssassemble at the float,needle removed and cleaned (or replaced if bad),and the carb re-assembled., Mercury Racing®. Mercury Racing® is known worldwide for its leadership in powerboat racing and production of high performance consumer and race marine products. Visit the Mercury Racing Website. Manufacturers of outboard motors and MerCruiser inboard engines, with over 4000 dealers in the United States., The 2 stroke, 25 hp Mercury outboard requires a 50:1 ratio, this is roughly one pint of 2 cycle oil, to six gallons of fuel., Re: 1999 Mercury 115 two stroke - 200 hrs. - Any opionons. MercGuy said: All 4 cylinders are moving all the time. During slow RPMs when 3 & 4 aren't firing, enough fuel & oil mix is pulled through the high speed jet to provide lubrication, but not enough to fire. It's a very, very simple system, with nothing to go wrong., Apr 9, 2005. Messages. 80. Jan 7, 2006. #5. Re: What should compression be at for a ELPTO 90HP - 2005. 90 to 115 psi for those engines is just fine . The main thing is their within ( and here is big debate lies )15% of each other.Some say psi and not % and some say no more the 10 psi or %. P., 2-Stroke Spark Plugs. Note 1: All NGK® spark plugs for Yamaha Outboards are sold in 10 packs. (Ordering 10 spark plugs will be equal to one box) Note 2: Refer to Technical Bulletin O2000-015A to ensure the correct spark plug and gap are used. Note 3: Refer to Technical Bulletin O2003-016 to ensure the correct spark plug and gap are used., Disconnect the Mercury Outboard switch and reset, if the engine fires, replace the Mercury Outboard switch. Check the voltage on the red and white Ignition wires at the CD Unit. If the voltage is less than 9 1/2 volts during cranking there is a problem in the battery s or the Ignition switch Box.