I have something going on with my 2018 50HP Tohatsu.
Here are the symptoms:
On two occasions the motor would not start. The first time it happened I thought I flooded the engine - although I didnt smell gas. This was some time in August. Second time I was in Muddy Bay this weekend. On both of these occurrences I let the motor sit for 30-40 minutes and it started up like normal.
On the trip this weekend while leaving the boat ramp the motor died on me twice. It also did the same thing back in the spring. It is not a slow death but a hard cut off…like no fire is occurring.
When I checked the fuel pump the line to motor there was pressure. The fuel filter appears to be clear too.
Let me know if more information is needed. To make it interesting anyone who properly diagnosed the issue gets a bag of Real Mullet lures…your choice of color.
water in gas? i don’t have a seperator on my latest boat, but i’ve had that problem before in my other boat. also, i had this issue with my generator lately and replaced with good gas and purred like a kitten.
@hammurred thanks for asking about the separator! I have one inline on the fuel system before connecting to the motor. I checked it both times by pouring the gas into a glass jar. It was clean. No water or contaminants
There are 3 necessary legs for a boat motor to run.
Fuel
Spark
Compression
Sounds like compression is good, fuel sounds good, so a remote diagnosis would point to spark, especially with the abrupt shut down.
Places I’d start to look are the lanyard kill switch, the key switch, and perhaps the low oil safety cut off, (not familiar with T motors, but it’s there id wager)
Without being able to lay hands on the beast, that’s all I got
How bout it Cobia?
I have a 50 tohatsu like yours and it sucks
Intermittent problems kill me
I wish it would just die
Mine runs on two cylinders for about twenty minutes and then everything clears up by the end of my trip.
For the first 20 minutes
It’s back and forth between two and three cylinders
Good luck
I feel your pain and frustration.
You could just stick a Phillips head screwdriver in the plug wire and hold it close to the spark plug and see if you have fire.
@sman I am scheduled to drop it off at Muddy Bay in Newberry SC on Tuesday. And I will do some troubleshooting tomorrow after church. Its definitely frustrating to have these types of problems!
Good news bad news…I discovered something interesting that I had a hunch about. The motor started up fine when I started troubleshooting so I decide to pull the cowling and let it sit in the sun. In both previous cases when the motor would not start it was top of the day in the hot sun. See this video of the motor not starting after sitting in the sun for 30 minutes.
Then I backed the motor into the shade and let is sit for another 30 minutes…Once it cooled off it started just fine.
@Mixed_Nutz Probably. I found some posts on other forms last night with similar issues on Tohatsu motors. Something called heat soak is the root cause for vapor lock. I don’t understand either of these possibilities so I’ve got some research to do
I get the boat back tomorrow. Tech could not get it to fail - started up just fine through all of his tests. What’s that saying about the definition of B.O.A.T? SMH
Anyway…looks like there is something heat related to summer time temps that is a catalyst to causing vapor lock. Its been killing me not to be on the water so I am gonna light it up in November! If you never hear from me again I will be stuck in the back of a creek somewhere on the Wando!
