Johnson 150 Starting and Milage Problem

1996 Johnson 150 Fast Strike. She is a real hard starter but once it does it will GPS at 63 MPH. once I shut it down and try to start, it will take a lot of crank’n to start again. I ran a tournament last Sunday and it blew through 16 gallons on a 12 mmile trip . Something is deffinately wrong!! The ball has a squishy feel to it and the plugs (NEW at the time) were dark and burnt smelling. A Co-worker said my plugs were too cold and that i needed to buy hotter plugs. I am hoping to resolve this without spending $800.00 thorough a mechanic. Please give me some input . Thanks

The first place I would look is the carborater. I had a 30hp Johnson that had some of the same problems you described. The problem I had with mine was the when I was running full throttle the main fly in the carb was opening too much. I adjusted it so when the throttle was wide open the main fly sat at a perfect 90 when compared to the opening. It solved the problem in my motor. Hope this helps.

I can’t remember if this motor has an individual carb for each cylinder or not. It sounds like a float is stuck open?
Therefore it is flooded after you shut it off, making it hard to start. Once running is it smokey? Burnt, dark plug will signify to rich or to much fuel in combustion chamber. Time to clean all carbs. Always run Sta-bil fuel preservative in your gas tank if you dont go through a tank full in a 3 month period. Just trying to help.

I’m back out
Yeti

Sumo, I think that is the boat I sold you this spring. The trick is not to flood it on the restart. I had the same problem until I figured out what I was doing wrong. On restart (warm) NO fast idle and don’t push in the choke (key). Just turn the key let it idle for 10-15 seconds and you will here the motor idle speed come up than should be fine. I think you are flooding it out. As for Milage, wide open eats gas, try to back it down to 3/4 for long trips. Feel free to p.m. me with any questions.

Putt2Winn

Not sure what size rig you are pushing but @ full throttle you will burn a pile of fuel. Each engine has a mind of its own. Try starting it as instructed as the previous owner stated. DO NOT PUT ANY PLUG IN IT OTHER THAN THE RECOMEDED PLUG FROM jOHNSON. I do not know what brand you have in there but I have always ran Champion in my boats. (all Johnsons) Your ball should pump up hard and stay hard. You may want to look at the hose from the tank to the motor. Do you smell raw fuel? Replace if you do. A can of Sea Foam can help clean the carbs. 1 can / 26 gallons I beleive, read the directions. You should be able to average 2.5 MPG to maybe 3MPG @ 5200 RPM. Full throttle / loaded 1.5 MPG, if your lucky. If these do not help, bite the bullet and take it to a reliable mechanic.

My hunch is the carbs need to be cleaned and adjusted. Over the years I have owned several Evinrude and Johnson motors, and almost without exception starting problems relate to the carbs.