2006 Yamaha 150 TXR bogging issue

[Saltyballs1]

my 2006 Yamaha 150 TXR starts and runs great for about 30 minutes, then bogs down to 4000 RPM. I've changed the fuel lines, water separator, fuel filter, VST filters, fuel pump, injectors, I'm at a complete loss. it runs great for 1/2 hour every time then bluuua

 

[Saltyballs1]

Wow, apparently I've stumped everyone.

 

[dingbat]

Wow, apparently I've stumped everyone.

The 30 minutes to act up would lead me to believe it’s an electrical/ignition issue

How is it acting up?
What troubling shooting lead you to believe it’s a fuel issue?

 

[Saltyballs1]

I made a few calls to repair shops to discuss the symptoms. That is how it became a fuel issue. Another reason is it dies when you put it gear slowly, common in Yamaha 4 strokes. That’s why I changed the VST filter. It is much more responsive now but after she runs for 35 minutes it acts like it’s starving for fuel. Feather the throttle and the RPM will jump a bot mostly stays 4000 I will look into ignition system also. For shits and giggles I’m changing the impeller this weekend

 

[mike_i]

Whats condition is the fuel primer bulb in when the motor bogs down? Is it firm or are you able to squeeze it? Is the fuel tank vent clear? Anyway to tempy run the motor on a portable tank?

 

[Saltyballs1]

Whats condition is the fuel primer bulb in when the motor bogs down? Is it firm or are you able to squeeze it? Is the fuel tank vent clear? Anyway to tempy run the motor on a portable tank?

ball is constantly the same firmness not soft or hard its new as well. i can not locate the vent but will try the external tank cant hurt

 

[Saltyballs1]

This issue was caused by a sticky thermostat.

 

[mike_i]

Thanks for the update, I learned something.

 

[99yam40]

This issue was caused by a sticky thermostat.

I see no way a sticky stat would cause it to bog down to 4000 RPM