Outboard motor revs high. You need to do the hub test. Then it runs fine with choke pressed back in. have you looked at the throttle linkage and butterfly to see if it is closing off to the idle position? also check to make sure the timing plate is moving with throttle goes back to idle. Some boaters like to run an incorrect prop size to get a better hole-shot or top speed, but doing so places additional stresses on the motor. Great for aluminum fishing boats, inflatables, sailboats, or as a kicker, the 8hp and 9. Every time I do this, out of nowhere, I will hear the rpms race up and feel speed 2003 Mercury 50hp outboard revs high when started in neutral? Mechanic's Assistant chat Customer: Why does my 2003 Mercury 50hp outboard engine rev high when I start it in neutral? Is your outboard jon boat motor bogging down or losing power? We will talk about the most common items that cause this. Whether you need a lightweight motor for a small boat or a powerful engine for offshore adventures, we have the perfect option. (66kmh) Max rated rpm a 5,800. Here's how to identify and fix them. Follow the manufacturer’s instructions or seek help from a qualified mechanic. What would cause my outboard to rev up by itself and go full power and not go down even if i turn it off 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'm going to wrench on a 20+ year old Johnson 70 this weekend in the driveway, looking for a short that occurs at higher rpms (3-4K) so I would want to give it some short bursts while watching the circuit tester The Honda BF25 and BF30 are 4-stroke marine engines. Jun 2, 2021 · My regular mechanic has no time and I'm no wrencher, but it seems the problem is in the choke mechanism vs carb. The reliable, quiet 115hp, 140hp, and 150hp outboard motors are ideal for pontoons, center console, multi-hull, and bay boats. 01 mph. net Outboards that see greater use, multiple-trip-per-week recreational owners and fishing guides, should be serviced every 500 hours. Bad Outboard Engine Oil Another incredibly simple potential cause of outboard vibration is bad engine oil. Either your motor is too high and ventilating the prop, or you’ve spun the bush in the prop. A Mercury 50 HP outboard motor circa 1980 Six cylinder two-stroke engine in 1984 Mercury Marine is a marine engine division of Brunswick Corporation headquartered in Fond du Lac, Wisconsin. Will Frist step, does the engine reach max revs under no load (out of gear). Mercury four-stroke outboard engines are designed and built innovatively to ensure high-quality performances as well. Im thinking the prop is underpitched? The stamping on my prop Why is your outboard not reaching top speed?Maybe your boat has lost acceleration, top speed, or just seems to be down on power. Normal RPMs and throttle control in forward and it revs up on its own in neutral. This is a brand new engine with brand new fuel. In this video from Boats. 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. IDLE REVES UP REALLY HIGH ON STARTING OR SHIFTING FROM GEAR TO NEUTRAL THEN DROPS TO LOW IDLE AND STUMBLES OR DIES COMPLETELY. Tried new plugs. I understand that you should not rev your outboard up in neutral or on muffs. I shifted it back into forward and it idled normally. Test and repeat: Adjust the height, take the boat for a spin, and repeat until you find the sweet spot for optimal performance and handling. Re: Engine revs high but lower speed Only other thing I can think of is, that when shifted into gear the the shift mechanism in the lower unit isn't locking in all the way, causing the unit to partially disengage. Running 14x19 SS prop. At low rev was working until 2500 rpm and then start to struggle again. revs way too high in neutral 06-02-2021, 10:41 AM 1992 - Yami 9. YAHAMA OUTBOARD ENGINE SURGES WHILE RUNNING. This powerful, quiet outboard motors are ideal for pontoons, center console, multi-hull, bay boats, and more. the motor almost feels like it comes half way out of gear. When boat is on plane, usually 3300 rpm and over, I have on mulitple occasions tried to trim the drive up. The Honda BF350 are 4-stroke 350 hp marine engines. Find high-quality used outboard motors at affordable prices. These lightweight 40hp and 50hp outboard motors are ideal for flats, bay boats, inflatables, fishing boats, and pontoons. May 21, 2008 · When travelling at higher speed and hit a big wave etc. A friends outboard will only rev to 4000 when in gear, however when in neutral revs up to 6000. After 2-3 minutes turned off, the alarm goes away and all Searay 17 ft bowrider with a 1999 Mercury 115 2-stroke outboard, A sticker on the engine shows the RPM limits to be 4750-5250, im getting 5500+ RPM with speedo showing 42mph, it would actually climb higher if not for the rev limiter. Check out the solutions here to fix them. High idles are caused primarily by too much air entering the engine after the intake. Here are 6 common causes of outboard vibrations. 9 are 4-stroke portable marine engine. When the engine oil is bad or stale, it reduces the outboard’s ability to perform and causes vibrations due to that poor performance. The Honda BF40 and BF50 are 4-stroke marine engines. 9 ESHQ 2 stroke As stated, the motor screams neutral. 9. Oil changes are “Maintenance 101”, so this should never be the cause, but it happens. It runs great up to about 4200 RPM. The main product line is outboard motors. At that time an alarm sounds (steady alarm) and the motor starts shutting down. We also know that each inch of the pitch can raise or lower the rpm by 150 to 200 engine revs at WOT, a relationship that is inversely proportional. Prop choice makes a huge difference to outboard acceleration, top-end speed, handling and fuel efficiency. 86 ratio and calculates at 4700 at 41. Unwanted vibrations could be more than annoying; they could be doing some real damage to your boat. Great for bay boats, aluminum fishing boats, pontoons, and more, the 25hp and 30hp outboard motors pack plenty of punch. Powerful and compact, the 60hp outboard motor is ideal for pontoons, inflatables, fishing boats, skiffs, and more. Any ideas? Thanks. All fuel lines, filters etc replaced. What’s wrong, will rev out to 6,000+ rpm on the flush hose, but put it in the water under boat load and it’ll only push around 2,500 to 3,000 rpm. As the pitch increases, the load on the engine increases too because the propeller “grips” a larger amount of water, leading to a reduction in rpm. I ran the engine for another 15 minutes to get back to the dock. There have been some queries on common issues with the Suzuki outboard Rev Limiter light. I use e-free gas, always run marine. Our selection includes top brands like Yamaha, Mercury, and Honda, all tested for reliability and performance. 9 Common Reasons Why an Outboard Dies at Idle (Explained) By Bryan Mullennix Outboard engines are a convenient and practical way of propelling your beloved boat through the water. However, like all engines, outboard engines are prone to specific issues. Its a 1995 200hp Yami outboard jet, 2 cyl. df 115 lose power at high rev 06-04-2021, 12:47 AM Hi there, Today I was cruising and all sudden the engine lost power , like was no enough fuel. My 1982 mercury 40hp 2stroke starts and idles for short time, then the motor revs high rpms by itself and I have to shut key off. When I start the engine it immediately starts to rev up a… Is your outboard motor not running at full power? Discover common issues and solutions with Rev Tech Marine, serving Virginia Beach and Hampton Roads. May 19, 2021 · When you say it revs high, for how long before you shut it down? It almost sounds like you pump the float bowl full, the engine runs the fuel level down, the engine leans out and the rpm increases. Jul 18, 2023 · Adjust the mounting height: Most outboards have adjustable transom brackets. Folks, I took my boat out for its spring shakedown cruise (been sitting since Nov). Frustrated with your outboard motor not running at full power? Here's all you need to know about these issues and how you can resolve them. If so, then that eliminates a number of possibilities (throttle linkage, governor out of setting). This extra air leans out the air to fuel ratio but raises the idle anywhere from 100 to 500 RPM based on the amount of air. I have a 2002 Sea Ray 225 weekender with a 5. At the dock the same problem persisted. For million $$$ sponsorships (or just Your beloved boat won’t go over 3000 RPM under load all of the sudden? Issues like this can be really annoying – everything seemed fine yesterday, but now, Outboard engine vibrations can be caused by a number of things, mostly related to basic maintenance. the Short shaft is 1. It also produces the MerCruiser line of sterndrives and inboard engines, as well as a lineup of electric outboard The Honda BF115, BF140, and BF150 are powerful 4-stroke marine engines. I can put it in gear and give it throttle to about 1,500 RPMs and it goes fine, but as soon as I try to raise the RPMs above around 1,500, it bogs out. I have a 1988 V6 Excel 225 hp Yamaha Outboard. 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. 42 ratio which calculator indicates 41. It is a good practice to squeeze the fuel primer bulb until firm before each trip to fully prime the system with fresh fuel. 0L EFI motor and Alpha One i/o. Any suggestions would be greatly appreciated. The reverse happens when we decrease the pitch. The Honda BF60 is a 4-stroke 60 hp marine engine. If I shut down the engine and then turn on/ off the key (without start the engine) I can hear the LP pump work. 9hp are reliable, compact outboard engines. At higher RPM (4500-5500), it will run of for approximately 5 minutes. One problem that many boat owners come across is the outboard motor stalling while at idle. What would cause my outboard to rev up by itself and go full power and not go down even if i turn it off I can put it in neutral and rev the engine up and it revs to high RPMs no problem. Re: Slipping through acceleration and VERY high revs at WOT It appears that the long shaft motor uses a 2. All went well, except it would not go to its normal 5,000 rpm-- would only go to 4,600 rpm. I just swapped out the lower unit and now I’m having issues. Tohatsu offers some of the best outboard two-stroke and four-stroke motors, which are also widely known as “bullet-proof” outboard motors. Have to prime bulb to Propeller pitch adjustment: Longer life for your motor, better fuel economy and improved performance are just some of the benefits of correct prop pitch. That is why Yamaha continues to push the technological boundaries in the design and development of our leading range of high performance props - ensuring every Yamaha outboard performs at its peak. 1986 Johnson outboard 70 HP. 01mph (66kmh) mph produces about 6,100 rpm w 10% slip. 9. Been bullet proof to this point. If I pull the choke half way out, it settles down fine and goes into gear. The Honda BF8 and BF9. Dec 16, 2025 · Why won't my outboard reach full RPM? Diagnose common issues like prop, fuel, ignition, or cooling problems to get your boat running smoothly again. It was suggested that I clean the carb. A serious student of the Honda outboard, Jacoby knew exactly what I was talking about when I mentioned a bogging BF90, and had some advice for BF90 owners: Get the revs u p: "The BF90 needs to be propped to run 6000 rpm at wide-open throttle, and that's with a full load of fuel, gear and passengers," said Jacoby. The speed cuts in half but the engine revs high and makes a loud sound as it does when out of water and you are revving in the backyard with just the water attachment on the back. In other words, an over-propped motor that lugs at WOT also lugs at quarter-throttle, just like an under-propped motor that revs too high at WOT does the same thing at quarter-throttle. 1en4um, fizeu, cqtt, hdiki, cgir, fcsy, i1uqp, 4gtg, z3ri, kl5yq,