JLarimar
Seaman Apprentice
- Joined
- Oct 19, 2022
- Messages
- 47
You are correct, there is a solenoid and prime starter unit and connecting linkage to the four carbs. I'm going to pull off the prime starter and test it as the manual shows.pull the stat and test in a pot of water as you heat it up, make sure it opens according to spec.
The only other thing that I can think of that could affect fuel to all Cylinders would be the prime start enrichment system.
make sure it is allowing the extra fuel when motor is cold and then closes off once the motor warms up.
Looking at a partes breakdown ,it lists a primestart and also some choke linkage.
so I am not sure what all that motor has on it.
just for the heck of it I will tell you my C40tlrx had the main jets drilled out by someone before I got it.
took me a long time to finally figure out why it had problems running high RPMs.
I replace the main jets and all was well.
if you have not owned this motor from new, you can not say if someone did or did not do stupid things to it before you got it.
Did this motor and boat set up ever run well for you?
if it has then you can rule out jet modifications, and just look for failing devices
![www.manualslib.com](https://static-data2.manualslib.com/product-images/6e5/909046/yamaha-f50a-outboard-motor.jpg)
Checking The Prime Start; Assembling The Carburetor - Yamaha F50A Service Manual [Page 119]
Yamaha F50A Manual Online: checking the prime start, Assembling The Carburetor. 1. Measure The Length Of The Prime Start Plunger. 2. Connect The Positive Prime Start Blue (L) Lead And The Negative Prime Start Black (B) Lead To A Battery As Shown. 3. Measure The Plunger Length A After...
this is the main thing, the motor was running GREAT for the last year, no issues or early signs of issues. After some cold weather in January got out on the water late in the month. The motor starts and idles fantastic, after putting it in gear and throttling up it starts choking badly and if run over 4 mph for a few minutes the motor will stall out when put back into neutral. Will only restart with WIDE OPEN THROTTLE. The plugs get black with carbon and it puffs black smoke on acceleration.