yahama stalling question - The Hull Truth

bill1084 · 06-27-2009, 07:50 PM

Out on the water today and had my first problem with my 2004 yamaha txrc 150hp (carbed motor) while chasing schools of bluefish at low idling speed ( starting and stopping) my motor stalled and would not start. After trying to get it started for about 25 minutes it finally started and i was on my way after using the choke. Cruised about for 40 minutes with no problem . Tried turning it on and re-starting it with no problem. Decided to try porgy fishing anchored up and fished for a while. I started up the boat and while pulling the anchor the motor stalled and the problem happed again this time it only took me 10 minutes to get it restated. Fished the rest of the day with no problems. Got home emptied fuel filter no water or sedement and also no water or sedement in the 10 micron yamaha water seperator. Pulled plugs they looked good. Tried to get the motor to stall in the drive way on the hose and it would not. What could have caused this??? Is it a potential carb problem?? Does anyone one have any idea ????

A1 Outboard · 06-29-2009, 10:16 AM

It would be helpful to know what you did while attempting to start the engine. Did you pump up the primer? Did you push in the key to prime the engine? Did the engine smoke more than usual when it started? Did the engine start on all cylinders or on several and then pickup the rest? Do you have winter gas in the tank that could cause vapor lock? Have you run an internal engine cleaner, into the engine, through the carbs lately? Do you run E10 fuel? The answer to these questions could help solve the problem. It is possible that the problem is ignition related. To solve either of these problems you may have to have a tech ride with you and try to duplicate the problem.

bill1084 · 06-29-2009, 02:07 PM

A1

I tried to start it a bunch of times when it didn't start i pumped the primer and it was hard. I also pumped the trottle to see if it would start . It didn't start. I figured i flooded it out from trying to start it. I waited about 15 minutes and tried starting it but it didn't start , I then pulled out the choke on the motor and it started but not on all cylinders. I pushed the choke in and gave it full power and i guess i picked up the rest of the cylinders when i did this. As far as gas i filled it up and 2 weeks ago. I didn't do any internal cleaning through the carbs. My gas is ethanol here on long island ny .

A1 Outboard · 06-30-2009, 08:40 AM

Three things are needed to start the engine, fuel, spark, and compression. In a two stroke engine you need compression both when the pistion moves up in the cylinder and when it moves down to pressurize the carnkcase. Many times the bottom piston ring will stick, because of contamination from fuel, when the engine warms up. Running an internal engine cleaner through the carb throats will clean the bottom rings and may help your starting problem. The cleaner should be used on a warmed up engine. Spray through the carbs untill the engine dies or the can is empty. You should see a lot of smoke. Let the engine sit for at least three hours and not more than sixteen hours. Restart the engine and let it idle untill the smoke stops. Go for a ride and blast it out at WOT. Check your sparkplugs, they may be fouled with carbon from the rings. Give this a try, it may solve your starting problem.

bill1084 · 06-30-2009, 10:20 AM

A1

Will do just what you recommended. Will let you know if that solves my problem.

bill1084 · 07-06-2009, 05:10 PM

Did the dunks decarbonizing method. I changed the fuel line for the water seperator and fuel primer ball to the motor. It seem to be idling and running smoother. It also seem to cure the motor from not starting . I developed a new problem. Motor would run fine when in neutral and once i would put it in gear it would stall. It seemed not to be running on all cylinders. I am able to restart it and it would happen again. Once started I am able to rev the motor up in neutral and it has all cylinders firing and sounds great. This problem does not happen all the time. I used the choke to start the motor was able to shift from neutral to into gear without stalling and was able to return to home port with no other problems. Motor had full power and rpms under load.
What is my problem now?????

A1 Outboard · 07-09-2009, 05:00 AM

You may have a problem with the idle circuit in the carbs. Try have them cleaned with an ultrasonic cleaner, and have the sync and link properly adjusted.

bill1084 · 07-14-2009, 03:18 PM

A1

Your diagnoses is correct.
It was the idle circuit. I had them ultrasonic cleaned, rebuilt with yamaha parts and then linked and sync.
Now motor runs great.