# gummed up carbs in a yamaha



## formerWAflyfisher (Sep 5, 2008)

So I went out and was unable to get my Yamaha 70 2 stroke started.  I played around with it and ended up pulling the carbs, they were filled with goop.  I think I got some bad gasoline, or just a lot of water in in my tank. I usually start my boat once a week and have never had problems with it before.  Well I have cleaned them out thoroughly and replaced the seals and the metering pins.  Do you guys know any products I could soke them in to dissolve any gunk I can't get to?  

Also I talked to the owner of a marina here in town and he told me I have to replace all three carbs because once this happens it will continue to happen again in short period of time.  To replace all three carbs would cost about 950.00 after tax .  What are your opinions?  Personally I don't think its worth it especially on a 6 year old motor.  I figure I will just pull them every six months or so and clean them out again.  Am I being naive?


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## topnative2 (Feb 22, 2009)

BS.--- try running some seafoam fuel treatment thru it
and call a local shop and ask them what they treat/soak their carbs in---comes by the gal. about $30-40--can not remember the name of it...i will try to track it down for you


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## Brett (Jul 16, 2008)

Drain and clean the fuel system, from tank to carbs.
Rebuild the carbs, kits aren't that expensive.
Sounds like E10 has struck again.


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## mmjamp (Jul 3, 2011)

In 10 years as a service manager I have replaced about 3 or 4 carbs and only 1 of those was a 2-stroke. You can soak your carbs in any automotive carb cleaner, HOWEVER *make sure there is no rubber or plastic at all on them or it will swell up like a balloon!!!!* 

In our shop we would just use the spray carb cleaner from autozone, napa, etc, etc, and a torch tip cleaner to make sure you got everything. A shop should charge about $350 for a complete carb job on a 70HP. If you just wanted to take it somewhere.

Don't just run seafoam through it, it may cause the motor to run better in the short term, but can cause a lean running condition if any thrash is left inside the carb and burn a piston.


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## twitch (Mar 4, 2007)

Napa has it, $25-$30.00.


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## formerWAflyfisher (Sep 5, 2008)

Thanks for the responses guys. I will get the carb cleaner at Nappa or autozone. I have the rebuild kits and will put the whole thing back together tomorrow. 

I will say this on a side note. That carb cleaner in a can is bad stuff. I had a tiny little bit fly into my eye, well holy god, I thought a lit match head was in my eye. I was able to rinse my eye out immediately. But man that stuff burns. It hurt for quite a while afterwards too... I will never use that stuff again without safety glasses that fit tight to my face...


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## Frank_Sebastian (Oct 15, 2007)

I clean carbs by soaking them in a can of carb cleaner with a wire basket for 15 minutes. After rinsing (with water) and blowing them out with compressed air I soak again in engine tuner overnight. 

Respect what Brett said about cleaning out the fuel system. If your gas lines are very old, you may want to replace them with ethanol rated ones. Otherwise you could have problems again. The main trouble you can have with that 3 cylinder is lose fuel to a cylinder and continue to run it. When there is not enough fuel to run there is not enough oil going into the crankcase and you will burn up that cylinder.

Frank_S


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## formerWAflyfisher (Sep 5, 2008)

How can you tell that you don't have fuel in one cylinder? I am assuming it sounds different when running?  Is it obvious?  

The fuel lines are fairly new, but I am going to get the tank drained and lines flushed.


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## mmjamp (Jul 3, 2011)

There is a couple of ways. 

1 Start the engine and pull the plug wires off 1 at a time to make sure the cyclinder is dropping. ( Use the pliars that are made for this don't just grab the plug wire and pull it off, or it will give you a nice little shock)( Never do this test on an opti, hpdi, or etech as it will send you to the hospital, A computer is required to do a drop test.)

2. Run the engine and then pull the plugs and inspect for a lean condition. Here is a link to understand what your plug means. http://www.theultralightplace.com/sparkplugs.htm


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