Thread: 50 HP stalling out

Stalling out yamaha: Stalling out yamaha - YouTube

A little more background needed..........was you having the same stall condition prior to cleaning the carb's?

Did you do the sync using vacuum gauges?

Sounds to me like you have a fuel starvation issue......... Did you completely disassemble the carbs and run a torch tip cleaner or small wire through the slow speed jets?

Did you measure the float travel?

Mid Carolina:
same stall condition prior to cleaning carbs.
Only sinked the carbs together, set carbs 1-3 to match #4. Cannot do the complete sinc & link as I do not have a tach. I did use a carbtune pro to. I do have a tach on order, waiting for to be delivered.
Completely disassembled all 4 carbs, used carb cleaner, cleaned out with torch tip cleaners, blew out with compressed air.
Measures float heights, set per service manual. All were moving freely.
Engine is a 2004 Yamaha 50hp four stroke f50tlrc.

Skunked, this does not help you fix your problem but I have a stalling problem with the same exact motor. Usually happens after I run back to ramp, slow down then go to open it up and it will stall. Does the same thing at times when loading on trailer, back off throttle to neutral then throw in gear and it will die. Have not been able to figure it out. Seems those carbs at idle are real sensitive to the motor being level so the floats are level. If my motor is trimmed up any past level it will not crank. I have just learned to live with it because other than that it's the best motor I have owned.

Went back and looked at the video again. When I first bought my boat used it acted like that scratched my head for a month or so. Now it ran great when it came up to speed. Checked plugs and found #2 was bad. Replaced plugs and has run fine since except for the occasional stalling I explained before.

Like any shade tree mechanic, I have a million ideas and probably 999,999 are not it!

Dumb question but when it does this, have you ever checked your fuel bulb and see if it is squishy? I'm sure you have but was just wondering. Cray is probably correct with the motor trim having something to do with it. Just sounds like a pressure/vacuum type issue to me. Almost like a starved for fuel or bubble of air? Just a thought. Wouldn't hurt to check the coils. I know of a mercury that had a similar issue and it ended up being a bad coil.

Good luck

Cray: makes me feel a little better knowing I'm not alone! It doesn't do it all the time. As for the carbs being sensitive, your not liyng! It amazed me how little adjustment was needed when I sinked the carbs with the carbtune pro. A 1/4 turn made a difference! I have not noticed a problem cranking when tilted. I replace plugs once a year, regardless.

Wicklundrh: not a dumb question, I have not checked that. Now I feel dumb! I agree, fuel or vacuum issue. I will check the coils though.

The intermittent issue is what's bugging me. Had it out today, get on the throttle it spits sputters. Next time, it goes fine. I should be happy that I had the carbs off, cleaned them, put em back on and it worked! Oh yea, caught six keeper crappie today!

My Brothers problem was the Quick-connect at the motor, O ring. It did not leak fuel when the bulb was squeezed but sucked air when running. it was always Intermittent

I also say its fuel line or fuel tank cap issues. If the vent on your tank is blocked that will happen also. Or the check valve in your primer bulb can cause that issue also.
Try hitting the choke when your going to open it up. If it runs fine then, you know its fuel related.
Pete