2001 15hp 4 stroke idling problems

[dieselfumes]

hello all. I have a 2001 20hp 4 stroke kicker motor that wont idle smoothly. it will idle but it is rough and some times it will pop and then stall. however It will start right back up and run for a while. also, when giving it some throttle it hesitates a little. then after running at a higher speed it will sputter after letting off the throttle. not sure if it matters but the squeeze ball on the fuel line has fuel in it but it doesn't seem to stay hard. ( not sure if it suppose to or not ) I have had issues with dirt getting into the carb in the past and clogging the carb needle. so I have taken it apart twice since I have owned it and cleaned and both times I have put a brand new carb kit in. float and all. each time I have measured the float to make sure its correct. I also did buy a repair manual and have adjusted the linkages and rpms to factory specs. gone over it many times to make sure they are correct. I also removed the tank and completely cleaned it. in addition after repeatedly having dirt in the fuel I have installed 2 fuel filters. one before the fuel pump and one after. the only thing that I can think of is the boat is a 21' with the kicker motor fuel tank located towards the front of the boat. to me it seems a long way for the pump to draw fuel. The engine did run rough before I installed the filters. in addition. i put the right sized filters and also made sure to install the clears ones so I can see if there is enough fuel and to see if there is any partials in there. so far everything is good. anyways , sorry to ramble on but I wanted to list everything I have done. its frustrating because my sons friend has the same motor and it run like a champ. thanks for any help. one last thing. I do have a pretty good mechanical back ground and I also have a complete shop to work on things............

 

[Star]

Re: 2001 15hp 4 stroke idling problems

The carb on that motor seems to gum up more than most. The idle circuit also has a built in restrictor so you need a really strong chemical cleanner. Have you adjusted the idle screw? I bought a used 05 15hp that sputtered and spit alot like you describ.e. It would start well and rev ok, but there was a miss that would come and go at different rpm. It would run smoth on #1 or #2 but if I connected both wires the roughness would return. Compression was not what it should be for a low hour motor. I pulled the head used 300 grit wet sand paper in a heavy plate glass table until it was flat and put in a new gasket and that fixed the problem. That was 4 years ago. The last compression check was 175# and 170#. The leakage of exaust gas into the firing cylinder was causing the missfire. I would do the carb one more time with a good soak. Ground your plug that you disconnect when you do the test!

 

[dieselfumes]

Re: 2001 15hp 4 stroke idling problems

Thanks for the help. I have had the carb off at least 10 times due to the needle valve sicking. But I haven't had that problem since I have put in the double fuel filters. also, while I had it a part I soaked the entire carb in sea foam. plus I run sea foam at least once a month and I add some in the oil just before i do a oil change. I guess I'll have to check into the back fire issue next. frustrating because my sons buddy has the exact same motor and it purrs like a champ. have joked about swiping his with mine lol. again thanks for your help..

Terry

 

[Star]

Re: 2001 15hp 4 stroke idling problems

Seafoam is a wonderful product but it is not considered a carb soak. taking a carb apart 10 times may not make it better. the idle circuit is really tinny. Did you adjust the idle screw? when these motors are setup right they are good running and easy starting. Have you checked compression. There is another warped head thread above!!!