The most common problems that we see with outboard motors of all sizes brought in for service at Highland Outboards are related to carburetors. Performance issues or failure to start/run are often the result of buildup of unwanted materials in the small passages, jets, and valves inside the carb. The effects that ethanol blend gasolines have on small engine carburetors are becoming widely recognized in the industry. The buildup of residues within the carb causes all kinds of problems that can potentially ruin a good day on the water. The typical symptoms of ethanol-related carb problems are:
* Hard/Impossible to start
* Motor starts, but dies at full throttle
* Engine does not idle or run without choke
The good news is that fuel additives are available to help neutralize ethanol and prevent the breakdown of today’s gasoline mixtures. We recommend the use of ethanol treatment and stabilizers every time you fill-up your outboard gas tank.
In this video we show a typical clogged carburetor diagnosis including disassembly and proof of root cause. This example is shown on a 2007 Mercury ME5M 4ST 5HP outboard, but would be very similar on Honda, Evinrude, Johnson, Yamaha, or other 4-stroke and 2-stroke outboard motors.
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Where is the video of rebuilding the carb? Great video. I have the exact same model and I think I have the problem mentioned above
Ethanol sucks!!
Thanks for this video, following your principles, I managed to fix my Tohatsu 3.5 2-stroke. Nice one.
Thank mate, good jobs.
Hey, I have a 1999 Force by Mercury 40hp and my carburetor get cold and sweat. Also some times it leaks gasoline. Any suggestions?
Good vid ! Question i have a 2.5 4 stroker with a brand new carb and it runs fine but ut leaks crazy amont of fuke through the vent hoses that are by the impeller hose why would it do that i mean i doubt the floats stuck or anything like that could it be the air flow screw to tight or loose ?
I really like your videos as i have learned a lot from them. I enjoy rehabilitating old Johnson Evinrude motors. Although I am at my whits end on a 1972 25 hp model 25R72R. i have changed out the powerhead, lower unit w/3 eared gears, seals, impeller, carb kit and even a rebuilt carb a "professional" installed kit. Now it acts like the carb is clogged and is dripping gas from what appears like its from the float bowl and does it with either carb i have for it. And the spark plugs seem to be dry. Also just replaced leaf valve gaskets as internal one was leaking. water into top cylinder. I know thats alot but any ideas and suggestions? ?
Thank You,
Kentucky Poor Boy
How come you never posted video showing how to rebuild this carburetor?
Thanks for the video. Do you have a video on how to rebuild the float? Cheers
where the rebuild vid?
I have a 1998 4.0 2 stroke Mercury engine I open up the carburetor I didn't find No Junk in it at all my engine has a good spark good compression but for some reason it turns on and it cuts off right away any idea but is really hard to get on to as well like if the fule not going into the system
Great video. Just had my carb rebuilt, motor started first pull and ran great. Second time, won't start at all. Fuel shoots out of the brass nipple on the top of the carb. Any ideas?
Hello, I have a Nissan 18hp 2 stroke, my luck with 2 strokes and carbs hasnt been good, 4 strokes im good… I think it needs some cleaning… When accelerating it stutters/ hesitates then runs like a screaming demon… all speeds are fine at steady, but if you go from just off idle to wot itll stutter for about 15 seconds then go, the whole time slowly revving, just not smoothly… Plugs good, new coils because the coil went bad last year.. It has been through several tanks of fuel now, and hasnt cleared of this issue… I havent found a place for nissan carb parts though… is it tohatsu as well?
Hi James, i have just bought a mercury 3.3 2 stroke… starts and runs very well, except i do notice that if tilt the engine up.. without turning off the valve and draining the remaining fuel in the carb, fuel starts to spill from the carb and in to my boat. is this normal?
thanks
D
I had this exact problem on a Tohatsu 5HP-Had to rebuild carb with new jets.Ran engine with TruFuel before storage and filled the gas tank with non-ethanol gas.Some marinas have non ethanol fuel available.
hello maybe you can help me i have a four stoke mercury 4HP more than 1 year i didn't star it. so when i try to start it. its nothing cannot start what should i do? i use only the internal fuel tank should i change the fuel? and check or clean the carborator? thanks
so how do you prevent gunking up with ethanol fuel as that is what's usually available?
really helpful video thanks I just like it
great video! and love the shirt!..lol