35 hp Johnson won't stay running

[Miller_Time]

Well, I've got problems again. When I first bought the boat, the motor would crank and idle fine but would not run at full speed. I cleaned the carb, put a kit in and ran the boat several times and the motor ran great. Took the boat out today and ran into another problem. While running at 3/4 throttle I felt what seemed to be fuel spray on my leg. Never found where the spray was coming from. Then the motor started cutting out and died. After trying to start and restart the motor, it wouldn't stay running. Looked as though the fuel line connector from the tank was loose. Took it off and on, primed it and cranked again, and it would run as long as it was choked. Got home removed and clean the fuel filter at the fuel pump and still will not run unless choked.<br />I know it could be several things, but can anyone help me out?

 

[NathanY]

Re: 35 hp Johnson won't stay running

I would replace all the fuel connectors and fuel line. If that does not help, check the fuel pump.

 

[OBJ]

Re: 35 hp Johnson won't stay running

Hey Miller_Time.....<br /><br />If ya' got to choke it to keep it running, then ya' got some blockage in the carb most likley. Try a couple things first, one....diconnect the fuel line from the fuel pump to the carb. Put it in a jar and crank the engine. If fuel spirts out the fuel line then most likely the pump is OK. Try laying a white cloth under the carb and remove the drain plug from the bowl. Let it drain onto the cloth. If ya don't see nothing, pump the primer bulb a time or to to flush the carb. If nothing comes out, I would pull the carb and inspect the jets for pluggage. The flushing routine is a last resort before pulling the carb. Make one more good inspection of the fuel lines for air leaks and make sure the gas line connectors fit snug to the mating connectors. If all seems OK, may need to pull the carb and check for foreign material in bowl or pluged jets. Let us know what ya' find.

 

[OMC-ALLtheWAY]

Re: 35 hp Johnson won't stay running

Its probibly either the fuel pump or your carb is pluged again, Most likely the carb if the fuel pump is shot it would correct itself when you pump the priming bulb, If it runs when the choke is on it means its running real lean not neccesarily starving for gas. I have 4 2cyl OMCs and the majority of the problems with them are the jets getting pluged. I realize you already cleaned it but it only takes 1 tiny peice of crap. Check your gas tank for rust if its an old steel one. If its rusty just buy a new one youl save yourself lots of headachs. It could also be your lines but not as likely as the carb. Try blasting it real good with carb cleaner.

 

[Miller_Time]

Re: 35 hp Johnson won't stay running

I'm going to take ya'lls advice and get back with you with the results. Think I'm getting air instead of fuel? The loose fuel line is what I hope is the problem. The tank I've got is plastic and the cap has a bleed valve on it, someone told me that if it's open the motor will not pickup fuel? I told him that I've run 2 tanks of gas through the motor with the valve open and it's ran perfect. <br />I'll get back to ya'll after I check it out.

 

[NathanY]

Re: 35 hp Johnson won't stay running

You will have to vent the tank to replace the out going fuel with air, other wise you will crush your tank, and your motor will not run.

 

[Miller_Time]

Re: 35 hp Johnson won't stay running

I pulled all the fuel lines and checked for blockage. Plenty of fuel and pressure. The fuel pump is ok, unless the line from the pump to the carb is clogged? I've got to pull the starter to get to it and the carb. Going to pull it tomorrow and clean and inspect. Hopefully that will fix it.

 

[22WRF]

Re: 35 hp Johnson won't stay running

Before you get into pulling the carbs as a last resort. Take off the air silencer start it up and spray some gumout in it the carb throat.<br />Don't put the gumout nozzle into the carb. Hold it back so the carb will suck in the gumout mist and don't spray enough to kill the engine. You don't want to wash all the lub out.<br />Do this several times and see if it don't smooth out.

 

[Miller_Time]

Re: 35 hp Johnson won't stay running

I replaced the fuel line and primer bulb, put a new fuel line connector on my tank and she cranked right up. The carb was starving for fuel so I guess the line or bulb was bad. Seemed like at full throttle, the line was leaking and sucking air. Hope this isn't a temporary fix! <br /><br />I did the gumout thing after I replaced all the old parts while it was running and it did seem to help. I'll definitely keep that trick in my memory. <br /><br />Thanks to everyone for all the advice and if I have anymore troubles, I'll be back here.<br />

 

[Miller_Time]

Re: 35 hp Johnson won't stay running

Well I thought it was fixed, but after replacing the lines and waiting two weeks till I could get to the river, she's still not running right! Still getting air somewhere. Going to replace all the lines from the tank all the way to the carb. Then take the carb off and clean the high speed jet. I can't understand why when I put the new fuel line on and ran it with muffs it cranked, idled, and ran fine for at least 15 minutes. Then today, two weeks later it would crank but wouldn't stay running. Then once it would run, it would run long enough to put into gear and then die when you gave it the gas. <br />I wondered if maybe the float is sticking starving it for fuel?