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Honda bf90 loose power

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Baksana

New member
Hey.
The question has probably been here before, but I have not really been able to find answers. I have a Honda BF90 4-stroke from the year 2000 which has been standing still for a year. i have now got it on the boat and got it on the water today. but first and foremost it is hard to bring to life. it "shoots" and just generally has a hard time keeping up. when it finally managed to get it started it goes really bad and goes up and down in revs. it has a hard time going over 2000 rpm. it simply goes out. does anyone have an idea what might be wrong? Unfortunately I forgot to record a video ....


sorry my english. I'm from Denmark :)
 
99.999% chance of DIRTY CARBS!

You can't leave one of these sitting for more than a few weeks without running fuel treatment through them, draining the carbs, or best, doing both draining AND treating!
 
And likely old fuel, too.

I'm not at all familiar with the 90's. But here is what I would try given that it's a carbed engine. I would hook up a portable fuel tank with fresh gas, add Sea Foam (1 part Sea Foam to 5 parts gas) or YamaLube Ring Free (2 - 3 ounces per gallon), get the engine running as best you can, then shut it down when you know that the mixture has circulated through the whole fuel system and cylinders heads. Leave it shut down for at least an hour. While shut down, change your fuel filter(s). Restart. Don't be surprised if you get a bunch of smoke and crap coming out of the exhaust. Repeat the treatment a second time. If that gets it going, then change the oil because it will likely be contaminated.

If that doesn't clean it up, then you're probably looking at a carb rebuild, as Alan implied.
 
I agree with the other guys....carburetors are gunked up due to residue from old gas not completely drained from system before storage.

Good luck to you and Happy New Year!��
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thanks for the answers. I will try to get the carbs cleaned. I discovered that the gas supply — the plug itself is very loose. I do not know if it could be a possibility that it does not get enough gas.
 
What Alan said.

Also, don't ignore the advice chawk_man gave you. That method just might do the trick on an engine that will still start and run. It's easier and cheaper than removing and going through the carbs to clean them and, even if it doesn't get you the performance you want, it doesn't hurt anything and will act as a "pre-soak" prior to taking off the carbs.

Good luck.
 
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