1998 S200TXRW Problems

[Tucker]

Gents,
Fired up sbd motor first time since early March. Ran for about 5-minutes and died. Started again ran for 15-seconds and stalled. Now it just sputters acts like it's starving for fuel. Pulse pumps new and confirm fuel getting to carbs. Even ran it on a remote tank, same results. Got boat late Dec and had engine survey done. Yam tech said carbs needed rebuilding so had it done. Fuel was questionable so drained tanks and refilled with 30-gals fresh fuel each and added stabil blue and ring free. Acting like carbs are plugged but how can that be? Onboard fuel sep new, and engine fuel filter new. I'm stumped.

[rodbolt17]

cause the carbs are clogged again most likly.
dont care what the bottle label reads.
it actually says "up to a year".
problem is boat tanks prior to jan 2010 and carbs are vented directly to the atmosphere.
this tends to shorten the life of even treated fuel to a few months at best and several weeks at worst.
just depends on temp and humidity.

[Tucker]

Thanks rb. The tech left me the old parts. So assuming the carb internals are good, how would you recommend I go about cleaning? I can't find your post about how you clean carbs. I remember reading about some plugs, etc that you don't take out because of threads stripping.

[rodbolt17]

if the fuel bowl gaskets are not damaged I sometimes can reuse them.
its the two large plugs at the carb top I dont remove, unless it sank.
unless I have to I wont remove the pilot fuel or air jets.
I will fill both bowls with combustion chamber cleaner and soak them an hour or so followed by a spray out with CRC-06064 carb cleaner.
problem with dealing with 15-20 year old brass parts that I dont know what the last monkey did, the parts like to rot and break or the last monky used ill fitting tools and destroyed them.
they can be inspected with a good flashlight with a focusable beam.

[Tucker]

Another observation. Just ran port motor and she purrs. Testing motors in tubs. Bad motor splooched like crazy. Huge oil slick on top, lower unit covered in oil. Good motor water was clear, very little oil residue. Huge difference, does this confirm gunked up carbs?

[rodbolt17]

nope, just confirms its not burning the fuel its getting, for whatever reason.

like I keep hammering, test spark.
test compression.
fix the fuel system.