Intermittent water stream 9.9 Merc

[FISH'N101]

Hello & Thanks in advance for any help you can provide. I have a 1999 9.9 hp 2-stroke Merc OB. The motor was purchase new but has 10-15 hours on it. I rarely use it. The water stream comes out of the top of the motor in an intermittent stream. Pretty steady & strong at low trolling speeds. When I speed up toward full power the stream becomes irregular. It will squirt for 5 sec on and 5sec off.<br /><br />I tried changing the thermostat and blowing out the rubber supply tube from the thermostat to the outside of the motor. No obstruction of any type noticeable.<br />I just picked up a new impeller to try. The local dealer said changing the impeller was easy even for the non-mechanic type. What do you all think.<br />Thanks Fish'n101

 

[alcan]

Re: Intermittent water stream 9.9 Merc

Hi Fishin<br />Changing a water pump empeller is a coman maint. job. This can be challenging for a first timer. how ever with the right atitude,a good manual and a little advice from this board, it should be more than do-able. Alot of time these empellers look good, the vains are not real worn, or they are not realy holding a set (bent over), but if you look closely and pull the rubber against hub, you will find that it has delaminated. Allowing the hub to spin or slip from the rubber. Good luck.