acceleration problem

[fisherindark]

I have a 87 force 125 on a 18.5 bayliner. It has been sitting for about 5 years. I cleaned the carbs and took it out for the first time yesterday. It ran fine As I accelerated. When I got to full throttle it started to jerk and act as it was losing gas. Could be old gas That I didn't get out of tank? Electrical? Carbs?

Thanks for the help!!!!!!!!!

 

[eurolarva]

Re: acceleration problem

Could be a bad fuel pump diaphram, air bleed into the fuel system, defective primer bulb, fouled plugs, week ignition, motor is not correctly linked and sync. I am sure there could be other things like prop is slipping, Clutch dogs worn. Going to need more information

 

[fisherindark]

Re: acceleration problem

The plugs are new. The prop is approx 2 yrs old. Haven't checked diaphram. Put a brand new stator on and has maybe 10 hrs on it. Put new bulb in fuel line.

It picks up and goes like it should when i throttle up. When I get Full Throttle it goes just a little and then it seems to slow a little. If I back off on the throttle a little it straitens out and I keep on riding. The if I try to go faster it repeats it self.

 

[john from md]

Re: acceleration problem

You need to change the fuel pump diaphram if the boat has been sitting that long. You also should do a decarb on it to get the rings loosened up.

John

 

[eurolarva]

Re: acceleration problem

Also check the throttle plates on the carb to make sure they are not going beyond wide open. It is possible to have these set so when at wide open throttle they will start to close in the reverse direction

 

[S. Robbins]

Re: acceleration problem

I have been chasing the same problem for a couple of years on a 96sportjet120xr. I have put new carbkits, fuel pump and diaphrams, fuel lines, primer bulb, etc.. No Help!!!!! Then, I sucked a reed into the #2 cylinder and had to get a new powerhead $3000, old parts on new powerhead = same problem!!! Accelerates then it acts like the engine is cutting out. If I throttle back, it will run ok, but if I throttle up again, surging gets more severe and engine quits if you dont back out of the throttle, it will run fine at half throttle. I am considering ordering a new stator to see if that fixes it. Please let me know if you figure this problem out. sorry I cant help.

 

[chitownborn]

Re: acceleration problem

yep john from md is right, it sure sounds like your fuel pump diaphram went south, on lower speeds the demand for fuel isnt that bad and the fuel pump can keep up and keep the carb bowls full, but when you put the screws to it the demand for fuel is high and youll drain the fuel bowls in the carbs and youll lose power slowing down, sputtering etc untill you slow down and the carb bowls can fill again ready for another short burst untill they empty again thats how come it repeats itself, a fuel pump diaphram is under $20 and only takes about twenty min to do real easy good luck don

 

[S. Robbins]

Re: acceleration problem

Is there any air in your fuel line when symptoms occur? Bubbles in inline filter?