need help with a stalling yamaha vmax

[bigkuntry1282]

got a 2007 stratos 285xl with a yamaha vmax 150 and took it out this week for the first time in over a year and when in neutral it will rev up no problem. but when put it in gear, forward or backwards, it will only get up to about 2000 rpms and then stall out. if you let go of the throttle then it wont die but if you stay on it then the motor will die.
any help is appreiciated

 

[stratos21xl]

Sounds like a fuel or fuel supply issue to me. Check the clear bowl filter under the engine cowl, it will be on the port (passenger side) of the engine. V-max's also have both low and high pressure fuel pumps. The low pressure pumps are known for failing, the diaphrams crack which cause them to lose pressure and the amount of fuel they pump. I think your motor has two of them and they are also on the port side of the motor and are silver and kind of square. To test them, loosen the bolts so they pull away from the power head slightly then pump the primer bulb. If fuel runs out from behind them then that's your problem. If all this checks out and it has fresh or known good gas in it, it could be the TPS (Throttle Position Switch) needs to be adjusted which will require a trip to the shop.

 

[Sniperchoke]

One simple check could be line or some other debris tangeled in the prop. Remove prop to check..

 

[bigkuntry1282]

i was thinking it was something with the prop area since it only does it when its in gear. i figured that if it was the fuel system then it would do it in neutral too.

 

[bronzeback45]

If its like mine its carbureted. Could be a hole in diaphram in your fuel pumps and is sucking air. I'm no mechanic but I've heard this before. Ethanol in gas will cause that if you let it set up to long and don't run engine often, might just be dirty carbs from the old gas.

 

[Buoy-Master]

When mine did it, I drop a cylinder.