02
Apr
I have a Johnson 70HP 3 cyclinder outboard that usually runs fine. In the photo below of my instrument cluster I was never able to get the engine over about 2300 with the throttle fully down.
Losing power at full throttle.
Boat motor loses power at full throttle. If the carburetor is clogged or worn it fails to efficiently balance the air and fuel mixture required for your engine to run properly at full throttle. This could cause stalling. Also your carburetor could be all clean but adjusted incorrectly preventing sufficient fuel reach into the engine and thereby causing power loss at full throttle.
Losing power at full throttle. Id also go with fuel pump diaphrams and non-return valves in the pumpsVerify this by pumping you hand primer bulb while at full throttle. If it picks up while youre pumping by hand its the diaphram pumps that are shot.
The boats motor will still operate and function as it should but the lack of a connection between the propshaft and propeller blades drastically reduces the boats top speed. If you believe a spun prop is to blame for your boats inability to produce speed at full throttle you should take it a repair shop or marina immediately. When I try to run the boat full throttle it will bog right down after a few mintues of running.
I tach out at around 4200 rpm and about 12mph. If I keep the throttle backed off a little from full it will run fine but I would like to get as much speed as I can out of her. My owners manual says I can run this motor full at 5400 rpm max.
One its starving for fuel. These pumps use the fuel to lubricate themselves and a blocked filter at the pump or your regular fuel filter will cause this to happen. Makes the same or worse sound as when you first turn the key on and the pumps primes itself.
Two they are in the early stages of failing. Brand new fc running rf1 brand new pdb with integrated regulators checked voltage plus the new motors and fcs only leaves the receiver and cameravtx as original. I am losing my mind.
The symptoms now are that it can still handle full throttle but will drop out of the sky when rolled. Went out Sunday and didnt even make it out of the harbour. Engine started fine revs fine in neutral but once over 3000 revs in gear loses power under load.
Has new plugs fuel lines all seem ok just seems it wants to kick on but splutters and drops back. Didnt stall at all just lack of power. The obvious effect this has on the engine is less fuel getting into the carburettor which can contribute to the engine bogging down and eventually it will cause the engine to stop completely.
Thats of course down to fuel starvation - if you suspect that the fuel tank cap is at fault slightly unscrew it to allow air to come through so its doing the job of the actual valve itself. At full throttle engine loses power. Loses power when throttle is all the way forward.
Loses power when throttle is all the way forward JA. Sometimes things that you think will be really complicated end up being easy to fix. Another possible reason your outboard motor is struggling to reach full speed is an air leak in your boats fuel line.
In case this happens there will be a constant fluctuation in the fuel supply pumped into your boats carburetors. As a result you will experience your outboard motors RPM fluctuating up and down. Like the title says 1999 50 HP Merc 2-stroke losing power at wide open throttle.
Things that have been suggested from bar stool Merc techs. Fuel filter fuel pump fuel lineprimer ball. Primer ball in the fuel line seems to be holding firm.
First time I pumped the ball this weekend it didnt release and stayed compressed. STOP running your engine until you find out why you dont have a full stream out the pee hole. It can cost you a pistonrebuild job.
Typical reason for less than full flow is a bug nest in the hose from pee hole to port cyl. I keep the pee hole taped over all the time except when using the boat. Top Reasons Boats Fail Sputtering or losing power In reality this problem can be caused by a variety of issues.
Everything from fouled or corroded spark plug wires to debris in the gas can cause sputtering or loss of power. Took it out and motor starts right up idles low power is just fine. Full throttle it cant get enough fuel and has the 34 to full power issue.
I then replaced gas tank fitting at gas tank fuel line and bulb fuel line fitting on motor side. Still the same issue. Shop said the new fuel pump might have been faulty - they warranteed it and.
Have a 2003 Honda 50 hp outboard- willrun good full throttle then bog down lower throttle picks back up. Then we had a problem where it loses power at throttle up over 2000 RPMs. The starboard engine does not have power between 2000 rpm and 3800 rpm.
That makes sense because of symptom of a spun hub is that as you increase power the engine will start to rev but the boat wont go faster because the hub is spinning. My engine wouldnt rev. In the photo below of my instrument cluster I was never able to get the engine over about 2300 with the throttle fully down.
GPS speed was about 235 mph. I have a Johnson 70HP 3 cyclinder outboard that usually runs fine. Sometimes it loses power to about 5mph at full throttle.
That may last seconds or 1 hour then fine for a week or loner. This has gone on for years. I can put multiple tanks of fuel through in a weeks vacation and it may run fine.
Ive taken it to a mechanic with no results. I also put a can of heet in it before I started out. Started up at first crack.
Got up to full spped and them lost power. Didnt run poorly just lost half power. Used my kicker then and it ran fine so gas cant be too bad.
Still think it is a fuel problem. Will drain 12 gas put in a can of sea foam and change the fuel filter. The correct propeller will allow your boats engine to reach its maximum recommended rpm revolutions per minute at full throttle trimmed up for best speed with a typical load in the boat.
I have a 2005 searay sundancer 260 powered by mercruiser 350 MPI. Noticed a slight vibration at 2000 RPM. Advanced throttle to full and could not get more than 3100 RPM.
Spin on fuel filter was clean. How engine loading and propellers interact with vessel performance Photo credit. When troubleshooting a LOW POWER symptom or a low RPM issue on any high performance marine diesel that uses mechanical fuel injection meaning NO Electronics or a true diesel that can run WITHOUT electricity this is how we go about it applies in 99 of the low power.
Sea Ray 290 Sundancer Port engine idles perfect. Anything more than 12 throttle it bogs down loses 300 RPM and constantly runs up a.