engine problems

[DDanhour727]

I have a 1990 yamaha cv55 2 stroke and I was out on the water yesterday and it ran great then on the way back to the dock i would not go past 5 mph even with the trottle fully engaged i checked the throttle cables and they seen fine.

 

[waffles1]

Re: running on half throttle

Re: running on half throttle

How old is the gas? Has it been treated? Does pumping the primer bulb help? Are your filters clean? Check your gas conections. There could be several reasons why it isn't running good.

 

[DDanhour727]

Re: engine problems

the gas is a week old. the motor has not been treated and pumping the primer bulb does not do anything and it is a new fuel filter

 

[Knightgang]

Re: running on half throttle

Re: running on half throttle

Do you have a water/fuel seperator on the system? Is the filter full of water?

Sounds to me like you either have a fuel issue restriction, water inthe fuel, or a carb needle sticking and starving a cylinder for fuel. If you are down a cylinder, it can seriously affect performance...

 

[robert graham]

Re: engine problems

Motor may be operating in "safety mode" caused by a high temperature or oiling system problem. Motor's computer causes engine to drop to 2000RPM's to protect motor until repairs are made. Do you have any alarm buzzer going off? Good Luck!

 

[DDanhour727]

Re: engine problems

I do not have a fuel water sep. I have had that buzzer go off in the past because of a faulty water pump but not this time and it does seen like it is running at 2000rpm's is there anything i can check to see if it is safe mode

 

[robert graham]

Re: engine problems

Your motor is probably a pre-mix so no "low oil" signal, so it is most likely a high temperature signal. Check water pump, thermostat, motor temperature sensor. The "safe mode" may save your motor from serious damage due to overheating but it may be a false alarm...better check it out. Good luck!

 

[99yam40]

Re: engine problems

I believe the pink wire on harness side of the temperature switch when disconnected and grounded to the block with the switch in the on position should cause the alarm to come in for checking the alarm function.