2018 Tohatsu 9.9 Won't Stay Running

blackd

Petty Officer 2nd Class
Joined
Sep 27, 2013
Messages
152
This new motor with about 12 hours on it won't stay running. It acts like it is is running dry of gas. I have always run it dry after taking it out. After it stops I can not pump gas using the bulb. Yes, the tank vent is opened.

Any suggestions?
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
That's a 2 or 4 stroke 9.9 motor, which model ? So you can't prime it again when the motor dies ? The bulb's arrow must be pointing upwards when priming. The carb could have a stuck needle and bulb not priming fuel to carb ?

Happy Boating
 

blackd

Petty Officer 2nd Class
Joined
Sep 27, 2013
Messages
152
Thanks SeaRider. 4 stroke, I was considering it might be a stuck needle or hole/loose connection in the under hood fuel line. Bulb pumps OK when disconnected and at 1st feed. After running dry bulb will no longer pump. Everything is new and ran well last year. It ran for ~ 10 minutes before it happened. It is now consistent.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,509
If this is a 9.9E, you are under warranty. See your dealer.
 

blackd

Petty Officer 2nd Class
Joined
Sep 27, 2013
Messages
152
Now, this is embarrassing! Can't trust an old man's memory.
I just dug out my receipt, and I was wrong about year and HP.
This motor is a 2017 and 15HP.
Model number: MFS15DEFL-8

I bought it at the end of Oct 17 and installed in early Summer 18.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,509
MFS15D. OK, check that the passage in the bottom of the carb bowl that feeds the accelerator pump is not clogged.
 

blackd

Petty Officer 2nd Class
Joined
Sep 27, 2013
Messages
152
I've (I think) isolated the problem to the fuel line or tank pickup. It might just be the primer bulb one way valves. Today I will change tanks and or get a new fuel line assembly/primer bulb depending on the tank results. If there is gas in the carburetor then its starts and tuns well until carb is dry.
 

blackd

Petty Officer 2nd Class
Joined
Sep 27, 2013
Messages
152
FINAL UPDATE: It was the pickup tube. It had come unattached and what was happening was if the tank was full or tilted such that the pickup connector was under gas it would run and pump. Ran it for 15 minutes on the tank after fixing it this AM.
 
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