Missing cylinder while running

jnewell

Recruit
Joined
Feb 22, 2010
Messages
2
I have a 1995 yamaha 115. I recently bought this boat used and have noticed a problem when running. The motorhas a choke built directly into it and the push button has fallen of and the previous owner installed an electric choke that uses a toggle switch that you can hold up to choke. While i am running i can move the switch up and it will speed up to full speed, kind of like a boost, but then return to where it was at after letting go, now holding the switch up will cause to to flood out. It also will do the same thing if it is choppy and the boat comes down hard, it will start to run wide open, thought i had a fuel problem or something clogging the fuel line but have changed fuel lines, filters, seperators and the bulb to no avail. has anyone got a clue to what this may be caused by? or have had any similar problems?
 

jnewell

Recruit
Joined
Feb 22, 2010
Messages
2
Re: Missing cylinder while running

Also wanted to say that i have checked the plugs and even changed them to see if that would helped and it didnt, all cylinders have very good spark.
 

douglloyd

Petty Officer 2nd Class
Joined
Jun 13, 2005
Messages
147
Re: Missing cylinder while running

Dirty carbs. Search for it. You will get an education.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,195
Re: Missing cylinder while running

If you are running lean you will destroy pistons. Clean the carbs and make sure the fuel system is clean
 
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