88 Force problems

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
My first time here, so be kind to an old man. Recently picked up a 88 Bayliner with a 125 Force on it. It ran great on the ears in the yard. Took it to the lake to try out. Water pump works, fine. Idles fine. Took off, after about a quarter mile at WOT, she started to cut out some and bog down. Backed throttle down to half, she ran fine, coughed a bit but ran fine. Went a couple hundred yards at half throttle, then back to WOT. Ran great for about a quarter mile again. Same situation all over again. Its got perfect take off, it seems only to be after running at WOT. Figured I'd start at the fuel pick-up tube and work my way forward to the pump then carbs. Also gonna check compression and replace the plugs this afternoon.

Anything else that someone who might have had the same issues, let me know.

Any and all help is always appreciated.

Thanks,
Todd
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: 88 Force problems

Fuel tank vent may have some kind of obstruction, mudaubber(sp) wasp, kink in hose, low spot in hose, etc.
 

aladin_sane

Seaman Apprentice
Joined
Jul 3, 2011
Messages
45
Re: 88 Force problems

I agree, either blocked fuel tank vent or bad fuel pump.
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,909
Re: 88 Force problems

It seems to be running out of fuel at high speed. So check the following starting with the easy ones while engine is running:
Check to make sure the primer bulb is not collapsing - if it is there could be blockage in the pick up tube, bad primer bulb with stuck check ball valve or tank vent is blocked
Check the fuel filter for fuel (if there is one installed after the fuel pump) if it empties or half filled then it could be a fuel diaphragm or air leak from the suction side of the fuel pump hose, i.e. quick disconnects
Finally, check if all of the above seems norm, then check the carb float settings.
 

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
Re: 88 Force problems

Fuel tank vent is clear, shot air through it. Fuel pick up tube was spotless, no trash at all or holes. Made a swab and checked tank, clean. Checked hoses back to fuel pump, with a vacum, all tight. Primer bulb, never really firmed up. Stayed squishy. Will change that this afternoon. Took pump apart and checked, no trash and all diahpragms looked good. Put back together, removed line and squirted gas through it. Gonna install a clear filter this afternoon between the pump and carbs. Removed both carb bowls, no trash. Checked floats and needle seat operation, couldnt tell any problems, but the floats could still be out of adjustment.

Can the spark plugs cause the original condition. Cutting out at WOT. Idles fine and mid range is fine for the most part.

Any and all help is always appreciated.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,074
Re: 88 Force problems

Plugs either fail or not.
Could be a coil breaking down(probably not).
If the ball doesn't get hard then somethings wrong there.
Replace it.It should get hard and after starting should soften.Not collapse.
Floats shoudn't be a problem.They would affect the performance all the time.
Replace the fuel line and squeezie.
Any inline connectors?Remove or replace.
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,909
Re: 88 Force problems

After making carb float adjustments and installing a fuel filter do a test run again. This time bring your tools with you. When it starts to stutter at high seed be ready to shut her down immediately. Do not even idle to see the current status of the fuel delivery system. If you have a clear fuel filter, it will indicate if the problem is in the carbs or before the carbs. If fuel filter is not be full of gas (its supposed to be full before you started the test), then the problem is upstream of the fuel filters. If fuel filter is still full of gas the problem is downstream of the fuel filter.

Check the level of fuel in each carb bowl. If the fuel is low on both carbs (and the fuel filter is full) it means something is preventing the fuel to fully stream into the carbs. Again this could be a float setting or clogged ports. If the carbs are full of fuel, the only thing I can think of is checking the timing at WOT.
 

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
Re: 88 Force problems

I plan on installing the clear fuel filter this afternoon, may even install some clear fuel line under the cowling. Could the main jets in the carb be stopped up causing this to.
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,909
Re: 88 Force problems

It can and it will show if the fuel filter is full and yet still stutters at WOT assuming the problem is in the fuel delivery. I use brake cleaner spray with that tiny red straw to clean my carbs.
 

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
Re: 88 Force problems

Everything looks good. Removed the carbs, cleaned with brake cleaner and air hose. No trash, nothing was stopped up. HOWEVER, the top carb mixture screw was set at a round and a quarter off seat. The bottom carb mixture screw was screwed all the way in, set it to match the top one at a round and a quarter off seat. Put the ears on and she fired up as soon as she was touched. Planning a lake test this afternoon. If these 2 screws arent set right somebody let me know please.

Everyone here has been a huge help so far.
 

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
Re: 88 Force problems

If the rain will hold out gonna take a test run today. Found a rebuilt tilt/trim pump from Caltric that was affordable. Tilt and trim are now working properly also.
 

lasso

Seaman Apprentice
Joined
Jul 9, 2012
Messages
48
Re: 88 Force problems

Took her out this past Sunday. She stuttered for a bit then began to open up. Trimmed the motor up and got to about 30 mph by the speedometer (which I know is off), Gonna take a GPS when we go back. Ordered a fuel pump rebuild kit. As soon as that comes in and i get it installed we'll try her again. What is the usual top speed for this boat/motor combo. Oh, by the way, compression check showed 134 to 135, consistent on all 4 cylinders.
 

SkiDad

Lieutenant Commander
Joined
Jul 18, 2010
Messages
1,518
Re: 88 Force problems

What is the usual top speed for this boat/motor combo.

our family has 2 of them - and they both will do about 35 with 6 people on boat and about 40 with 2 people. one is 18' and one is 19'
 
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