2007 Yamaha VMax 150 issue.

[Twilley]

I'm looking for some advice/help with this issue.
The motor will start up fine but seems to idle a little rough. When I attempt to rev it up it appears to "choke out" and dies. I can run all day at just above an idle speed but anything over that and it boggs down and ultimately shuts off. I have always been able start it right back up (with a lot of smoke). The motor seems to smoke more than it has in the past. I have taken it to a mechanic and they said it was checking out fine, changed fluids, plugs etc, however it was never water tested. The problem is that in the area I live, Yamaha is not a common brand and most mechanics are hesitant to work on it. The nearest one I could find was 4 hours away.
I have read that the issue may be an O2 sensor but I can not seem to locate one on this model. If anyone could tell me if this model has an O2 sensor and where it is located, I would appreciate it. I have also checked the fuel pumps, oil pump and the rest of the fuel delivery system and have not found any issues.
Any help would be appreciated.

 

[mjf55]

I do not believe that a 2007 VMax 150 has an o2 Sensor. I searched Yamaha parts diagrams for a V150TLR ( 2006 and newer) and the search came up empty.
I would suggest purchasing a factory service manual ( read, not SELOC or other) for your model. There should be diagnostics built in , but the service manual should help diagnose the issue.

Note that engines perform differently when on muffs vs in the water, due to the load on the engine from the water.

Maybe someone with direct knowledge of your engine can help/