Just cant figure this out...

[Cup420]

Per a few mechanic, friends of mine, I put two cans of marine seafoam in my tank and ran the absolute stew out of my boat the other day. I think I drove a total of twenty three miles straight. Ran the motor as hot as I possibly could and kept running on full throttle. She idols beautifully, but when i'm trying to get on plane, she starts bogging down around 4000-4500 rpm. She WAS staying there for about two minutes before heading up to 5000. That actually improved. But I still have the bog and the ever so slight push push...push push. Fuel filter is clean, spark plugs are new, getting spark on all four cylinders, compression is good, carbs we're rebuilt last february, fuel plump was replaced last february, coils were replaced last february, maintenance has been kept up 100%. Vacuum lines have been checked and are strong, fuel lines are all brand new, as well. I really don't want to go through the job of tearing those carburaders down again.But I guess if I have to I will. Also I have ran nothing but ethanol free in this boat, since i've had it. Yamaha 50hp 2003 4stroke

 

[Captain of the Double G's]

Correct spark plugs ?

 

[Chris1956]

When she bogs, hit the choke button for 1/8 sec and see if she picks up. If so, it is some sort of fuel delivery issue. If not, maybe an ign issue?

 

[boscoe99]

No choke in a 2003 Yamaha F50.

 

[Cup420]

Correct spark plugs ?

Yes

 

[Scott Danforth]

no such thing as a mechanic in a can.

 

[Chris1956]

So no choke on that carb? Interesting.

 

[Cup420]

So no choke on that carb? Interesting.

Nope

 

[jlh3rd]

When she bogs, hit the choke button for 1/8 sec and see if she picks up. If so, it is some sort of fuel delivery issue. If not, maybe an ign issue?

It does point to an intake leak/ temporary lean condition or some kinda restriction in the idle to main fuel flow.

I'm unfamiliar with outboard ignition advance, but needs to be checked.

 

[Cup420]

Yall...I may have found the answer and its simple....the stupid bulb! I went to the river the other day and for the first time, it wouldn't stay pumped up. Im gonna say it probably went bad about 2 months ago and I just figured it was something in the motor. Well...I guess we learn as we go...

 

[racerone]

Primer bulb on the hose does not stay hard when motor has started.

 

[airshot]

Yall...I may have found the answer and its simple....the stupid bulb! I went to the river the other day and for the first time, it wouldn't stay pumped up. Im gonna say it probably went bad about 2 months ago and I just figured it was something in the motor. Well...I guess we learn as we go...

Don't feel bad, the primer bulb is one of the last things thought about when an issue arises. If suspect, best to replace the whole fuel line with a new bulb. Forget buying those gray fuel lines from walley world or other discount places. Go to NAPA and get good quality fuel hose and make your own..

 

[Cup420]

Primer bulb on the hose does not stay hard when motor has started.

I hadn't started it or even had the boat in the water at this point.

 

[Cup420]

Don't feel bad, the primer bulb is one of the last things thought about when an issue arises. If suspect, best to replace the whole fuel line with a new bulb. Forget buying those gray fuel lines from walley world or other discount places. Go to NAPA and get good quality fuel hose and make your own..

Replaced...I had grey but changed over to black

 

[dingbat]

Go to NAPA and get good quality fuel hose and make your own..

Be careful with fuel lines from auto parts stores...been burned a couple of times before I started digging into things

For example... the Dayco hose marketed at a number of auto parts stores as 30R7 fuel line" is in fact "not suitable for gasoline/oil mixed and alcohol blended fuels" per the manufacturer data sheet.

A double whammy for those that premix their fuel