help '98 Force 120hp runs great on land, wont run on the water???

[Jiggz]

Re: help '98 Force 120hp runs great on land, wont run on the water???

The problem is intermittent so you will have to do many testing to pinpoint the source of the problem. You need to be prepared to troubleshoot when the problem starts showing up. First sign it won't start, use a spark tester and test for spark. Use the one that goes between the plug wire and the plug with a see through body so you can see the spark. Then be ready to switch fuel hose with an external tank with fuel ready to go. If there is no spark then you know where the problem is. If there is spark, disconnect the existing fuel hose from the pump suction end and connect the standby fuel hose with the standby fuel tank. If the engine still would not start, disconnect the fuel hose line from the inlet side of the fuel filter. Crank the engine and check to make sure fuel is pumping out to indicate the fuel pump is working. If it is working which means fuel is being pumped out, the only thing left to check are the bowls of the carbs. The probability of both carbs clogging is virtually non-existent. With a see through fuel filter you can avoid many of these troubleshooting steps by interpreting the fuel filter. if the engine will not start despite the fuel filter full of fuel, the problem is most likely in the carburetor. If the engine will not start and the fuel filter is empty or half full, the problem is most likely the fuel pump sucking air (indicated by bubbles in the fuel filter) or clogged suction lines or faulty fuel pump. To isolate problems related with fuel tanks, use an external tank.

 

[kobe24]

Re: help '98 Force 120hp runs great on land, wont run on the water???

Well i tryed it again today and found its not a fuel problem like i thought.. first time i tryed it, it started so i ran in and got the camera got it on video this time. Does it sound healthy to you?? RPMs where low, about 850rpm in N and the motor seemed to be running ruff. You can see the pulg wires shaking in the vid. http://youtu.be/W4dGxbe8kKs

This time when it started, it started with a backfire from the exhaust. Its never dun that before. After it ran for a while I shut it down and started it again. Then i shut it down for about 5min and tryed it again, wont start. motor is geting fuel, i pulled the fuel filter out of the lower housing so i could see it and it was full of fuel the hole time. There where no bubbles in it while it was running or while i was cranking it after it wouldnt start. Also after a few min of cranking when it would'nt start, fuel started dripping from bolth carbs.

I pulled the pulgs after it wouldnt start the last time i tryed it and thay where wet. Im going down to napa tomarow to get a spark tester to check for spark. The prob is easy to recreate, if i shut it down and let it sit for a few min it wont start back up. Ill post the spark test results sun or mon.

 

[jerryjerry05]

Re: help '98 Force 120hp runs great on land, wont run on the water???

Back to the tank,the fuel pick up,it unscrews from the tank.Look close.
Unhook the fuel vent,blow back through it.
If the squeezie goes flat and stays that way and the vent is clear then replace the squeezie.
Done a compression test?

 

[Jiggz]

Re: help '98 Force 120hp runs great on land, wont run on the water???

If the fuel filter if full the whole time then we can assume it is not a fuel problem unless there is problem with the carbs. But with all the plugs wet, it tells us there is fuel going into the cylinder. So now we know the problem is most likely a spark or electrical problem. Let us know of your spark test results. if after running and then you shut it down and then it won't start, first thing to check is to make sure the kill switch wire is disconnected and then try again. If problem persists, then standby to check for multimeter testings. If you can locate a wiring diagram of your motor it'll make testing easier.

 

[kobe24]

Re: help '98 Force 120hp runs great on land, wont run on the water???

Sorry for the long delay. i was hurt at work and out of commision for a while.

I finaly found the prob. who ever worked on the motor before i bought the boat did'nt install the choke correctly and it was flooding the motor out. so i reinstalled the choke (correctly) and problem solved. thanks for all the help fellas. its much appreciated.