Outboard motor loses power at full throttle. The motor is on an 18foot Jon boat. One such issue … Outboard Motor 1994 Johnson 90 HP - runs fine up to 2/3 throttle. Can sit there for a It would not go to full throttle. Limped back home at 30% throttle. The most likely cause of the 90-HP engine losing power at full throttle after a short time at that setting is due to loss of fuel, likely caused by a restriction in the fuel supply or a marginal fuel lift pump. Solutions and Fixes for Slow Speed at Full Throttle With a clear understanding of the causes, let’s look at some solutions and fixes for increasing boat speed, even when running at full throttle. The boat’s motor will still operate and function as it should, but the lack of a connection between the propshaft and propeller blades drastically reduces the boat’s top speed. I'd also go with fuel pump diaphrams and non-return valves in the pumps<br /><br />Verify this by pumping you hand primer bulb while at full throttle. Check the age and condition of the fuel. Includes an overview of the 4, 5 and 6 HP T Hello, I have a 1984 Mercury Black Max V150 2stroke Issues- Rough idle and no power wide open. Lately while driving around at full throttle the engine would bog down as if its losing power and will not run right the rest of the day. Should have more power I figured. However, as with any mechanical equipment, sometimes issues can arise that can cause the motor to lose power or run inconsistently. Shop said the new fuel pump might have been faulty - they warranteed it and The 70 hp 97 engine starts and idles fine. . The fuel pump is new all the hoses are new as well as one of the tanks. When working correctly, these engines provide an enjoyable and hassle-free boating experience. <br /><br />I don t think it could still be a gummed up carbs, but. We’ll talk about ten typical outboard motor issues in this article, along with solutions. Any ideas or suggestions? In this video I am cruising at a speed and RPM I was able to sustain and then applied full throttle. Jun 2, 2025 · If your outboard motor is not running at full power under load or bogging down at full throttle, the most common causes include a spun prop, fuel line air leak, spark plug corrosion, or debris in the propeller. What can I look at to get it to run at the standard 2000rpm? I have Limped back home at 30% throttle. Learn more. And can't go above 5mph. When open up to full throttle, motor loses power. I can back off to 2/3 throttle and it runs perfectly. Initially, the boat hopped right up on plane and the engine would run at 5000 rpm at full throttle. Why is my outboard losing power? Discover the top 5 causes and how to fix them for good. Ever what you should do when your boat motor loses power at full throttle? Have no fear we go over exactly what to do in this situation. You’ve had your boat out for a few trips and lately you have begun noticing a slight power loss in the upper RPM range – above 4000 RPM – yet when you throttle back the engine and cruise at lower engine speed it runs fine. Is there a way to We have a 98 25hp Evinrude that has an annoying habit of intermittently bogging down or losing power when we run at full throttle. And yes I know you said you replaced it but that's the indicator or partially plugged pickup tube in the tank. Now it starts fine stays running but I only get about 1/3 on the throttle before it chokes off and dies down like i lose significant power. This 150hp engine was designed to satisfy the needs of the recreational boating community looking for a quieter engine with fuel-efficient power for small to mid-sized boats. Jun 2, 2023 · Here are some possible causes of power loss in 2 stroke outboard engines at full throttle: Now that we’ve identified possible causes, let’s delve into troubleshooting and fixing the power loss issue in your 2 stroke outboard engine. Engine runs full throttle at 4000 rpm & only 18 mph Re: 15HP evinrude losing power at full throttle If and when you remove its carb, be carefull to keep the bolt inside all the starter parts when loosening, removing the manual pull starter as you don't want all that to come apart. I have a 25hp Evinrude that loses power after running at full throttle for few seconds. In this article, we delve into this common and vexing issue. This guide explains how to identify and fix each issue. I then replaced gas tank, fitting at gas tank, fuel line and bulb, fuel line fitting on motor side. Re: Motor bogs down when going to full throttle As you transition, or "tip in" from idle, the mixture needs to be substantially richer to avoid fuel drop-out and bogging. Background this motor was sitting for 6 years due to previous owner passing away. While some outboard motor issues can be resolved quickly, others call for more involved fixes or expert assistance. Learn More About Your Boats Systems By Joining The Born Again Boating Academy! https://www. Still the same issue. bornagainboating. I pushed the chock in, bam, up on plane and sailing so fast my hat flew off. In this article, we’ll explore the various reasons why this may happen and what you can do to prevent it from happening in the future. One of the problems is that it is completely unpredictable as to when it is going to happen. It’s a scenario that every boater dreads – the frustration of an outboard motor that was running smoothly one moment and then inexplicably loses power the next. Replaced prop with a new one. When the engine loses power at full throttle, check the fuel system first—inspect the fuel filter for clogs and ensure the fuel pump delivers adequate pressure. The boat has a large outboard jet unit on it. Open the throttle of our brand new Yamaha F25 and you’ll immediately feel the effect of Yamaha’s innovative technologies at work, delivering big-engine features with unique power-to-weight performance and outstanding economy. Took both aluminum props to the dealer today. The throttle was wide open from the 0:25 mark onward. Somewhere between the engine and the fuel tank. The Mercury Verado outboard engine has been known to experience back-pressure blowouts to wide-open throttle. I seem to get full power and it's not misfiring. Dec 5, 2025 · A boat losing power while the engine is still running is typically caused by a fuel delivery issue, an ignition system failure, or improper ventilation. I just bought a 1998 Mercury 40 hp outboard (serial # 0G660803, model 40M?). full throttle it can't get enough fuel and has the 3/4 to full power issue. You are likely experiencing the result of a boat that has been sitting for a period of time and debris Table of Contents About The Yamaha 150 Outboard Engine: Yamaha Marine released its new F150 four-stroke outboard engine to the market in 2004. Properly trim the boat: Utilize trim tabs or an adjustable outboard motor to fine-tune the boat’s trim, reducing drag and improving overall speed. Electrical components inside the housing of the engine. 2000 and older two-stroke-power-cycle models. This can cause the boat to lose power, and even stall. We can get the motor to full power by squeezing the primer bulb while underway. When it happens we stop the motor take it out of the water for a Re: 25hp johnson loses power after full throttle i concur with monte. 1995 Suzuki DT25 3 cylinder. Here are the best and quickest ways to troubleshoot and resolve this issue! What Are The Symptoms of An Air Leak?. If you believe a spun prop is to blame for your boat’s inability to produce speed at full throttle, you should take it a repair shop or marina immediately. Do you ever find yourself cruising on your boat, full throttle ahead, only to suddenly lose power? It’s not only frustrating but can also be dangerous. . Sometimes the motor will kill altogether and other times it will Spring is well underway and we are about to roll into summer. Could not go over 30% throttle without revving up like it is slipping. Why does my 2006 150 optimax outboard motor lose power and warning tone come on? Following a thorough service, including a full motor service and fuel drain, the boat has started to experience power loss above 4000rpm, despite having only approximately 900 hours of use. I have a basstracker pro guide v-16 w/60hp 4 stroke engine. 1. Took it out and motor starts right up, idles, low power is just fine. It will run at wake speed for about 10 minutes {With the throttle on max}then sputter to full power, it may or The engine loses power or gets weakened out in idle. For boat enthusiasts, outboard motors are a must, but they can be problematic if not properly maintained. This Bogging down of an outboard motor at full throttle can be caused by various factors. Jan 9, 2025 · Is your outboard motor isn’t running at full power? Learn troubleshooting tips to restore performance from OS Marine. Bill Cable ived owned about 9 outboard boats over the yearsout of those engines, the Yamaha was the best all around engine, and it was great on fuel. Re: Losing power at full throttle. When the problem is happening, the motor will run smoothly at idle and at low throttle while in forward gear. No Start to the Engine An … So, what causes a boat motor to lose power? Perhaps a frustrating question, but a highly important one to avoid losing time on the water. Not much. Starts and idles great but once I get to 3/4-full throttle I can run a couple hundred yards and it loses power. Regular maintenance and timely inspection can help identify the issues some of the reasons mentioned above. 2 hours into the new prop, same thing happened, cabin cruiser wake came along and the engine revved up like a spun prop. Limped back home. Probably 30 hours total on engine. Let the chock out back down to half throttle, all with the throttle lever at full. today we dive in to find the culprit of a outboard running really crappy, and the outcome really surprised me personally but was super simple and maybe simpl A discussion of outboard motor starting problems, some of the causes and quick solutions, aimed at non-mechanics. 10 Reasons Why A 2 Stroke Engine May Lose Power Now regardless of whether it's on a garden strimmer, lawnmower or chainsaw, whenever we pull the throttle on a 2 stroke engine and get a bogged down sound it's almost always caused by an insufficient amount of fuel reaching the engine. Get expert tips to diagnose and resolve engine issues, ensuring smooth rides every time. Suddenly, your outboard motor sputters, loses power, and leaves you adrift. Fuel Issues One of the most common reasons for a loss of power in a boat is fuel-related issues. So, with the throttle push to wide open it would run as if only at half throttle. Moreover, we’ll provide you with valuable insights into diagnosing these problems and offer practical solutions to get you back to enjoying the water with confidence. com/Get Your Born Again Boating Clothing! https:/ Re: Mercury (Classic) 40 hp loses power on full throttle Typically when a motor starts, idles, and runs well at full throttle for a bit, and then performance dies down it is a failing ignition component. The most common fix involves checking and replacing the fuel filter, inspecting spark plugs, and ensuring the fuel tank is properly vented. This is done to prevent corrosion. However, after approximately 1/2 hr of operation at high speed (35 mph) the engine had lost power so that 3500 rpm full throttle was all it had and it was difficult to get the boat up on plane. Maybe this fuel pump is in the early stages of going out and I am losing fuel pressure at WOT until the motor loses power in a very smooth manner at lower fuel pressures? If this is the case, then the motor is running lean while decreasing RPM to a rate that the Fuel pump can keep up with. Feb 4, 2022 · Is your outboard motor not running at full power? Discover common issues and solutions with Rev Tech Marine, serving Virginia Beach and Hampton Roads. they are great engines Sounds like a weak primer bulb or fuel pump. Below I give some advice on the operation of the Mercury outboard engine WARNING HORN or AURAL ALERT SOUNDER as used on many Mercury outboard engines, particularly c. Reason for the Problem: The fuel injection system failure may cause this. Hello, my 2+2 only kicks in around 3000rpm after a lot of throttle travel. The main relay is usually sealed with any potting material. Defects in the fuel injection system can also be the reason. Jun 7, 2024 · We’ll explore the various causes behind outboard motors suddenly losing power, from fuel-related problems to mechanical issues. Outboard motors are a popular choice for many boat owners due to their efficiency, reliability, and ease of maintenance. I do manage to get to 6000 RPMs this time with the motor trimmed up a good but at the 0:50 mark the power drops off again and its not able to get up much over 5000 RPM again. So what do you do, you ask? Why Does My Outboard Lose Prime? Outboard engines lose fuel prime because of an air leak in the fuel system. Any ideas? I did a carb rebuild, new gas tank and hoses, fuel pump is relatively new kind of at a stalemate with this work horse Did not strike anything, but after a cabin cruiser wake sent some water over the front, the engine revved up and it sounded and acted like a spun prop. Engine looks remarkably clean, but bogs down to the point of dying when I go from idle to full throttle. Ahoy all, Our motor will not run out correctly above half throttle we believe the new style plastic floats may be to blame. maybe fuel lines are closing up internally also, unless they are new , its basic maintenance, cheap insurance , replace them too. dsiv1, bkihrg, p6xf, epqh5, 35wy, 3w4osh, sfkj, alvyof, olht, fzkv,