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Yamaha 40HP Four Stroke motor
Manufacture date: 2005
Tiller model with electric start, has 3 carburetors.
I bought this in 2008, it has run fine for years. Last time it was out was in November 2011. I changed the oil, plugs and lower unit oil in the fall of November 2011. Tried to run the engine dry before putting it away, but I am sure some fuel stayed in the carbs.
Last year (2012) I sold my home, moved to the Minneapolis area, and then a number of things happened last year where my boat stayed in storage for 18 months...
So today is the first time out with it, did all my pre flight checks over the last couple days, oil, lower unit, you name it. (didnt shange the plugs, because I figured they were fine as I only had one trip on them.
I completely cleaned both fuel tanks (6 gallon and a 3 gallon) and filled with fresh new gas (with Marine StaBil and Yamaha ringfree) and flushed the fuel line and bulb. Fired it up in the driveway a couple times, seems to run ok, a little rough, but I figured once I get out on the water and open it up for a little while it will clean out.
I was wrong, in neutral I can rev the engine, a little bog going WOT but not bad. In gear, couldn't even get above 6 MPH. rough idle, wants to stall out, 25% throttle its kinda ok, but trying to get anything more would cause it to bog down.
So I beached it on some sand I found, and swapped plugs (I always carry a second set, habits from my old two stroke days) The plugs I pulled out were wet, and possibly a little oil residue.
After changing plugs, it still behaves the same.
I think that it is running way rich and is flooding out, but I may be way off too. I just dont have much experience with multiple carb setups, so I am a little nervous about pulling it apart.
So a couple questions, would you think the problem is in the carbs? maybe some varnish caused parts to get sticky and hold open?
If I pull the carbs, do you need to do a special synchronization procedure like when working with multi carb setups on motorcycles? Essentially balancing the cylinders?
Any thoughts, let me know.
I will post pictures of my plugs that I pulled after about an hour of running, hopefully they will help describe part of the problem or might be able to point me in the right direction.
Manufacture date: 2005
Tiller model with electric start, has 3 carburetors.
I bought this in 2008, it has run fine for years. Last time it was out was in November 2011. I changed the oil, plugs and lower unit oil in the fall of November 2011. Tried to run the engine dry before putting it away, but I am sure some fuel stayed in the carbs.
Last year (2012) I sold my home, moved to the Minneapolis area, and then a number of things happened last year where my boat stayed in storage for 18 months...
So today is the first time out with it, did all my pre flight checks over the last couple days, oil, lower unit, you name it. (didnt shange the plugs, because I figured they were fine as I only had one trip on them.
I completely cleaned both fuel tanks (6 gallon and a 3 gallon) and filled with fresh new gas (with Marine StaBil and Yamaha ringfree) and flushed the fuel line and bulb. Fired it up in the driveway a couple times, seems to run ok, a little rough, but I figured once I get out on the water and open it up for a little while it will clean out.
I was wrong, in neutral I can rev the engine, a little bog going WOT but not bad. In gear, couldn't even get above 6 MPH. rough idle, wants to stall out, 25% throttle its kinda ok, but trying to get anything more would cause it to bog down.
So I beached it on some sand I found, and swapped plugs (I always carry a second set, habits from my old two stroke days) The plugs I pulled out were wet, and possibly a little oil residue.
After changing plugs, it still behaves the same.
I think that it is running way rich and is flooding out, but I may be way off too. I just dont have much experience with multiple carb setups, so I am a little nervous about pulling it apart.
So a couple questions, would you think the problem is in the carbs? maybe some varnish caused parts to get sticky and hold open?
If I pull the carbs, do you need to do a special synchronization procedure like when working with multi carb setups on motorcycles? Essentially balancing the cylinders?
Any thoughts, let me know.
I will post pictures of my plugs that I pulled after about an hour of running, hopefully they will help describe part of the problem or might be able to point me in the right direction.
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