Logo
FULL SITE MENU

1990 Force 50HP sputters at more than half throttle

L

Lav6880

New member
I have a 1990 Force 50HP and the problem I’m having is when I go more than half throttle it will start to sputter. It runs great below half throttle and idles great. It will pick up speed for about few seconds but then sputter and even shut down if I don’t pull the throttle back. I’ve changed the spark plugs and the fuel filter. I’ve also tried the sea foam stuff to clean out the fuel line. Last time on the lake it picked up for about 2 minutes and then the same thing happened. Anybody has ideas? I’m a beginner to outboard motors but I can get by.
 
Water in the fuel?Do a compression/spark test.Then check/rebuild the fuel pump.
Clean the carb and while it's off check the condition of the reeds.
Any in-line connectors?They can leak and suck air.I remove them.
 
Thanks for your comments. I already did the fuel pump. Took it to a local mechanic last night and he noticed that the vent on the fuel tank cap was all the way closed which needs to be open while running. I also ordered a new carb so I'll replace it since it's 21 years old. If I do everything at once I wont know which one fixed the problem so I'm taking it one by one. The next is to replace the fuel line from the tank to the fuel pump.
I'll keep you updated on what happens.
 
It turns out they didn't have the carburetor so I ordered new parts, gaskets, nozzle, jets, float and replaced them. I also replaced the fuel line with new primer ball. Now it won't even go half throtle, bugs down right away if I give it gas. Idles ok although it looks a little rough. Now sure which way to go from here. Any sugestions?
 
You have a manual? Try to find the Force manual.
If the float isin't set right it will bog and stall.
boats.net Force Forum and the first thread.FrankA posted a thread:called a linc and sinc do that.
Later today i'll try to post a pic of the float settings.J
 
Last edited:
I noticed that the new float isn't the same size so I tried putting the old one back in and still no luck. I don't have a manual. I'll try and get one.

That picture would be helpful.
 
Picture 006.jpghttp://forums.iboats.com/showthread.php?t=449011 Here!! Really sorry about the pic.Worked really late yesterday and fell out early!!! Will try to get the pic today.J

Managed to get the photo.J
 
Last edited:
Thanks a bunch. I bought the manual yesterday and found the exact same page so I set the float like this late last night and haven't had a chance to test it yet. Once I run it and see how it goes I'll update you.
The carb sync instructions from Frank are great but they are for 75-150 hp and multiple carbs and my outboard is 50hp with one carb. He talks about the needle adjustments which I don't think I have on my carb. The only thing I can adjust while idleing is the idle mixture screw.
 
No you DO!! have an air screw,top front.The towershaft is to adjust the idle.
The air screw is in till it just bottoms and then out 1 and 1/16th.My camera screen took a crap.If you need help finding the towershaft look up your motor on a parts print out.The towershaft will be listed there somewhere.It's connected to the sgift cable and the top to the trigger.J
 
Right, I've tried setting the air screw at different positions but none of it made a difference. I know where the towershaft is but I have not messed with it at all.
I ran out of patience and took it to a mechanic today. He choked it while running, that seemed to really work which means that it's not getting enough fuel again. Not sure why as I've done or replaced everything around fuel but something is still not right. I'll see what the mechanic says and update you.
 
Ok, so the mechanic fixed it in a few hours. Says the carburetor main nozzle wasn't pushed in all the way and wasn't reaching the fuel, that was the last thing on my mind. Took it out to the lake and it ran execellent but started to shut down at idle even though it was idleing great at the shop. Why is that?
 
Back
Top