2000 175 Johnson Fuel pump

[JJB]

2000 175 fresh rebuilt 2 hrs on it ! has vro pump! I am having a problem getting my 175 to idle smooth at the 600 to 1200 rpm range it did run good above that .I have cleaned and rebuilt the carbs set floats to factory spec. Set the timming and Throttle pick up to factory spec . Did a commpression check and it is good and even in all cyl . I connected a remote gas tank , new primer bulb and gas lines to the fuel connection on the engine to rule out my tank and still rough at idle . I notice if I keep pumping the ball nice and slow and it gets better . My question is that the engine was sitting for 6-7 months and only started on a stand for 5 min a week . It was using double oil during those months and still is . That why I rebuilt the carbs and they did have build up in them and it did help with the upper rpms and idle . I was wondering if the fuel pump needle and seat has build up on it also ? or maybe the fuel pump is starting to go bad ? It looks like it is the original vro pump unit . Sometimes I hear a click in the vro unit when I prime the carbs .
Thanks for your input .

 

[Gary H NC]

Re: 2000 175 Johnson Fuel pump

Buy pumping the bulb and it smoothes out would make me think you have a leak somewhere.Running double the oil would also make it faster to gum something up when setting the 6 months.
I'm sure the pros will chime in with ideas..
Was any Stabil used in the fuel when setting?

 

[Silvertip]

Re: 2000 175 Johnson Fuel pump

If you are running six month old fuel with double the oil that alone could account for the poor idle quality -- especially if the fuel was not treated. Top off the tank with fresh fuel and see what happens.

 

[HighTrim]

Re: 2000 175 Johnson Fuel pump

If Im reading his post correctly, I believe he tried running off a remote tank to rule out the fuel. Im assuming of course he put fresh fuel in the remote tank. If pumping the primer bulb improves things, I would look at carb floats improperly set or defective,failing fuel pump air motor diaphragm ,leaky or dislodged pulse hose between crankcase and fuel pump,etc...

 

[JJB]

Re: 2000 175 Johnson Fuel pump

Thanks for the replys , I always use seafoam and fresh fuel during storage and I am running fresh fuel now ! High trim , I have the carbs set 1/32 on the one setting and 1 1/8 on the drop setting . Which adj would you adjust and to what spec ? the book calls for 1/32 only on the one adj and between 11/16 to 1 1/8 on the drop . I notice if I put the remote tank raised up on the back of the boat it keeps primed ball nice and hard with good flow but still misses some . I going to check all hose connection on the pump now . Thanks for the input

 

[HighTrim]

Re: 2000 175 Johnson Fuel pump

For the drop, just set it somewhere in the middle of the specs, around an inch, it is not as important. Positioning of the float is. Turn carb upside down so weight of float closes needle. Float should be parallel to gasket surface and to the spec, 1/32.