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Yamaha 2009 8hp 4 stroke won't start

SailingPriority

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I purchased a new Yamaha 8hp 4st (2009) and it has never run right. More time in the shop then on the boat. First it would race while in idle until put in gear. After a couple of weeks of this, it wouldn't start at all. I took it back and they rebuilt the carb. (at my cost). Immediately took it back to the boat and in order to keep it running you needed high RPM (too high to even attempt to put in gear). I took it back and it ran fine, idled right down. I took back to the boat, had good luck for a few weeks and now can't start again. I took it back to the shop, they have had it for 2 wks and say nothing wrong. I have no faith in the engine at all. The shop is a long drive from the boat and I honestly wonder if the drive itself isn't freeing something or shifting something that causes it to run. The engine has less then 10 hours running time. Any thoughts? I go to the shop to pick it up but really have no reason to believe it won't be in a state where I can't start it again. The shop will work with me, but they are offering no advice. BTW: I always bring my gas can with the engine, so it isn't the fuel which is fresh with factory suggested additives.
 
Read your owners manual.----------I have seen some Yamaha motors that will run at fast idle automatically untill they warm up.---------Then run normal.---------Always run fuel out of carburetor when motor is going to sit for a week or more.
 
never run the gas out of any carb, the o rings will crack and dry out
use a marine stabilizer and run the motor at least 1 time every 3 weeks

sounds like your PDI was never done right
 
what are you asking
once a o -ring gets soaked in fuel then there is no fluid around it, it cracks

your outboard skills are so-so

are you a certified technician or just an auto mechanic trying to go marine>
 
i had a very similiar problem. 9.9 2000 4str. brand new would not act right sometimes would not run at all. the dealer i bought from sent me to a different dealer. both thought nothing was wrong with motor. i finally found a mech. that tried hard enough to find the problem he had to call the yamaha headquaters in georgia i think.they were aware of the problem but problem was design and the owners manual and the dealers service manual neither had the info the techs needed to fix it. i have not felt good about my motor and yamaha did not impress me with their costomer service. while you might have a different problem an adjustment of the linkage arm under the carb is what fixed mine, again this differs from what the book called for. actually the instructions for starting the motor in the owners manual do not work and the yamaha tech gave different instructions. so dont think you did something wrong.
 
Always run fuel out of these 4 strokes when they sit -----Small passages plug up easily when fuel sits in them for a long time.------------From 40 + years of outboard repair " know how "
 
I guess I am guilty of not running the fuel of mine and it will sit for 2-3 months some times, sometimes longer. I do pump up the primer bulb when I walk by the back of the boat in the shop. Also pump my 225 Honda fuel primer bulb. My 2009 T.9.9 definately cold blooded, but keep the choke out for a little bit and then it runs great.
 
Saw some local folks with a brand new Yamaha 9.9 HP in the spring. Did not use boat all summer and in the fall motor just would not start.---Following year same problem after I coached them, so now when they have a problem I just chuckle quietly to myself.
 
if you run a marine stabilizer you never will need to the gas out of the carb
usually its the owners that do not close the fuel tank vent letting in moisture

also running the gas out of the carb before you trailer it you will wear out the needle in the carb and change the float height while you trailer down the road

if you plan on storing the motor, use the highest octane gas and stabilizer
seafoam works great
 
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