50hp force help, with fuel delivery problems

[Fishermanfromks]

I have just recently bought a Bayliner bass trophy with 50 hp force and needless to say it is far from a trophy. I rebuilt fuel pump, put in impeller, cleaned carbs, and was heading problems with it dieing at wot. I replaced the fuel line and put in New gas tank without quick release. I took it out and it ran like a champ. I took it out the next day and it was doing the same thing. It was running better but nothing like it was the day before. It was hauling but, now I can barely pick up any speed. Thanks.

 

[jerryjerry05]

Re: 50hp force help, with fuel delivery problems

Mixed gas with oil?(sorry gotta ask)I know you've been working on this.
Do a comp test.Spark test too.
Comp/spark can change in 1 trip.

 

[Fishermanfromks]

Re: 50hp force help, with fuel delivery problems

Yes it does take mixed gas. I did comp test and they were both at 110# and the spark test was good. I did find a loose wire that the top plug runs too on the coil module #1. I'm hopeing when I tightened it it did the trick.

 

[Fishermanfromks]

Re: 50hp force help, with fuel delivery problems

Well New plugs and tighten that wire didn't work. I'm running out of things to try. Could it just be a problem with planeing as to why it wont open up and go.

 

[tater76]

Re: 50hp force help, with fuel delivery problems

My rule of thumb with these motors is keep it simple. Start with the basics, compression, spark, fuel delivery. Whereas you already installed a fresh pump kit, new gas line, and tank you need to look at your fuel line connections for air leaks and carb tuning.

Is the primer bulb staying hard when pumped?

Is your carb adjusted correctly?

Air screw turned out 1 1/4 turn from lightly seated?

Float adjusted level?

Fuel mixed 50:1?

These are all things that will cause issues with fuel delivery. Once you have it tuned properly, then you can go about setting it up correctly on the boat for optimum performance.

110psi is a little low, but it can vary with the tester. I have a 55hp that runs great with 110psi, but its about due for a rebuild as it has lost alot of power.
Don't expect too much from the 50hp. I put one on the 16ft tri hull in my avatar for testing, and only got 22mph out of it running and set up perfect. I now have an 85hp force on that boat, and it does close to 40mph fully loaded.

 

[jerryjerry05]

Re: 50hp force help, with fuel delivery problems

The comp at 110 like Tater said is low but both being at 110,that means the guage is probably the problem.
Now we need some more info?? Year,serial# model?Do a spark test.
If it's not getting to the higher revs? Possible bad coil,plug,loose connection?
Not getting the fuel?The compression runs the fuel pump.
Since your in Russia,gotta know they use Ethanol there?
Profile,Location?

 

[Fishermanfromks]

Re: 50hp force help, with fuel delivery problems

I figured out it wasn't dyeing at wot. When I pushed throttle all the way down the valve was shutting. So when i stoped at wot it just was running about half its capacity. But I wasn't for sure which was the air screw and I cant see it in my book. But the screw with the whole thru it that I believe is the air screw was seated all the way down.

 

[jerryjerry05]

Re: 50hp force help, with fuel delivery problems

The valve was shutting???
What motor we working on??
You say air screw all the way in?It wouldn't run good at low speed,maybe not start?
It's for slow speed running.Shouldn't affect high speed.
Pics of the motor,serial#s model#s
Screw with the hole??? Pics.
The air screw should be on the top front of the carb.

 

[Fishermanfromks]

Re: 50hp force help, with fuel delivery problems

507xbc is model serial is 1572. And yes the throttle valve goes past open and closes again at full throttle. I cant push throttle all the way down. I checked float and it was off, not parallel, so I fixed that.

 

[Fishermanfromks]

Re: 50hp force help, with fuel delivery problems

I was thinking the screw on top front was idle speed. Also maybe its called throttle shutter, not a valve

 

[pnwboat]

Re: 50hp force help, with fuel delivery problems

Screw on the top front is probably the idle mixture. # 27 in diagram. That should be 1 to 1 1/4 turns out from lightly seated. Actual setting depends on your particular motor.

Mercury, Mercruiser, Force, etc. - CARBURETOR - FORCE 1988 50 H.P. "C" MODELS

Idle speed is a screw with a lock nut on the tower shaft. Here is a picture of a 1996 or later 40HP motor. Yellow arrow points to the idle speed adjustment screw/nut. You should have something similar on your motor.



The throttle plate should go back to the closed position at WOT. Something in not right there???? Typically the throttle shaft has a mechanical stop that would prevent this from happening. Does your carb have one of the two piece throttle plates? There's a small spring on the plate (#23). Make sure it's there. See diagram above.