I have a 2003 15 hp 2 stroke Mercury outboard. It cranks ok, idles ok, sounds a little rough, but idles with no problem, opens up to about half throttle and runs great until you try to open it on up. That's when it starts bogging down. If you open it all the way, it drops off and boggs way down, let off on the throttle to about half throttle and it runs ok. I tried spraying carb cleaner into the carb when I had it wide open and bogging down, it almost choked it out. After a few seconds, it would pick back up enough to keep running. Did it several times, same result each time. According to your video, this would rule out fuel delivery issues. What electrical component failing would cause this? We have rebuilt the carb, replaced all fuel lines, fuel filters, and primer bulb. I am not a mechanic and am at a loss as to where to go next. Switch box, stator, trigger, all are too expensive for me to start guessing. Help!!!
Too many things it could be... normally it is the carb that needs a clean, not sprayed into the carb, but taking apart and cleaning. I do note that the post is months old
My fuel filter is running dry at idle and bogs as I initially apply throttle, but the engine runs fine at speed. Recently cleaned the carb and replaced warn out fuel tank, primer ball, fittings and hose. ???
I’m having a bogging issue on my mercury 4 stroke 100 hp outboard engine but it doesn’t always happen. It occurs sometimes when a go full throttle and bogs down but most of the time it fixes its self and goes back to normal but other times it would just cut out and just won’t restart and I have to wait like 30 minutes for it to start again. Pretty annoying problem I have a feeling their might be salt water in the tank just ordered a new fuel filter aswell. Very rarely I get the smell of petrol which make me worry that their might be an air leak in the tank the most annoying part was spending all the money on a service that just didn’t help at all
thanks for the reply and advice using a relatively simple/cheap method. I have a big problem. Fixed a bad plug wire but I’m bringing a can just in case to check things out if the new wires don’t do the trick
Thought I watch this . Hey someone who knows something helpful and Real good ! But pull the trailer out next time from the bushes spiders bad LOL. like n sub
I have a question about a 2016 Mercury 3.5 4-stroke I've owned it for over a year I've taken it out and put so many miles on it I know it very well.... a couple weeks ago I was in it and I was almost home and then all of a sudden it hit a noticeable RPM change (higher) causing the Wake to shrink behind my boat.... it only lasted for about 10 seconds maybe a little bit longer and then it stopped and went back to running how it's been all along and I'm not sure what the problem is ....I've had the carburetor off and apart so many times I bought a brand new fuel pump brand new spark plugs....
Im fighting wit a heck of a bog on my 99 Merc 90 2 stroke. Took the boat out today and sprayed starting fluid in each carb. top two carbs seemed to have no change but the bottom carb would increase rpm. I forgot my timing light so I didnt try thatt yet. Anyy ideas? Thanks BTW great video!
Have you installed clear fuel line? Sorry for the late response. If all fuel is clear and getting to carbs without air. First thing to check is. After it runs for 5 mins. Measure the amount of fuel that comes out of the drains on each carb. That will tell you if its lack of fuel supply. Next if fuel level is the same from top two as bottom two. Asuuming spark isnt the issue. I would say there is a pluged main jet inside the lower carbs
Queistion: MY 1985 Mariner only boggs when I give power in the water , not out of water and/or when tests out of lake. What's my problem. It does not stop running but when given power from idle in the lake it boggs down as you have described. Help!
Sounds like all your testing needs to be ina lake or pond. Try to keep it on the trailer just incase. What happens when adding additional fuel during the bogg? Likly sucking air
Ahhh so adding additional fuel via aerosols has no effect. So the next trick would be to connect a timing light to each spark plug wire one at a time while bogging. Point the light at your face amd watch for a loss of light. Multi cylinder engines while loaded can have misfires seaming light a bogg but really a miss.
Mine bogs on take-off and then slowly picks up rpm and takes off. It doesn't do it when the motor is pretty warm, only when I haven't had it running for a bit while using the trolling motor. Does this sound like the same issue?
@@carlosvelasquez2774 try doing a compression test. It should be over 100 psi, most older engines have piston rings that are worn. If the pistons and rings get hot it could be loosing compression and causing the problem.
I have a 2005 40tlrd yahmaha 2 stroke it runs ok and I can get up to full speed for a while then it will either shut of or it will bog after a little while, I think I will rebuild my carbs. I noticed that two of the carbs just stop working then I turn it off and start it again and it works.
New tohatsu 2023 barely used started to drop in acceleration at high rpms. I have to drop throttle to 0 and then it restarts again, any higher load like a current or waves, causes it to drop acceleration to 0. Started happening after i took it to the ocean what a shame, thousands of suggestions from everyone and none worked so far
Clear fuel line right before the carb. Different hose and tank. Inline spark tester. Can of brake clean. Take it out. During the problem spay brake clean right into the carb. If it gets better look into a lack of fuel situation. If it gets worse watch the spark and see what's dropping out.
You most likely have water in your fuel. Check the fuel filter if the redring is floating there's water in your fuel. Also make sure your fuel lines from the tank are tight and not sucking in air.
