Force 125 that will not plain out

[gonefishing1]

Hi I have a 1987 force 125 that I put on my boat this year. My boat controls are Johnson?s. The motor starts and runs but in the water it will not take off and bring the boat up on plain. It will not turn more than 2500 RPM?s. I have done a compression test on all cylinders 120 to 125 psi. I have spark on all 4 cylinders. Today I?m going to clean the carbs out. I noticed the gasket on the bowl was torn in half and it?s missing one of the gaskets on the nut that holds the bowl on. Any help on this matter is greatly appreciated.

 

[pnwboat]

Re: Force 125 that will not plain out

There are quite a few problems that may cause the symptoms you describe. I would suspect that maybe a fuel flow issue may be the problem. Your initial tests on spark and compression seems to eliminate any obvious problems in that area. Doesn't 100% totally eliminate any problems here, but for now I'd move on to the fuel.

Make sure the fuel tank vent is not plugged up. If it's plugged up, the fuel pump will not be able to pump fuel to the carbs. After you fix the carburetor gaskets, double check the needle valves in the carbs to verify that they are not leaking. To do this, tilt the motor down to it's normal running position and pump the primer bulb 4 or 5 times. It should get firm. Check for any leaks from around the carburetor bowls and vents holes.

While under way in the water, does squeezing the primer bulb have any affect? If it does, then I would suspect a bad fuel pump diaphragm, or plugged pick up tube in the tank, partially plugged fuel hose, or maybe even a bad primer bulb itself.

 

[gonefishing1]

Re: Force 125 that will not plain out

Hi pnwboat thank you for the reply. I cleaned the carbs out and made new gaskets to replace the missing and bad ones. I found the lower carb was not getting gas at all! The jet was pluged shut. I'm going to test it out in a few. I will repost my findings later.

 

[gonefishing1]

Re: Force 125 that will not plain out

Hi I'm on the lake right now same thing 6.5 MPH. I'll get it sometime

 

[pnwboat]

Re: Force 125 that will not plain out

Do the primer bulb test, squeeze it while under way to see if it makes any difference.

 

[gonefishing1]

Re: Force 125 that will not plain out

Hi you got to love cell phones. I tried unhooking the rectifier. I herd that could be it. I tried the primer bulb. In neutral I could wined the motor up by hand but under a load nothing. I was adjusting the carb at idle to see if that would help and noticed that the lower carb didn?t affect the idle at all. So back home cleaning the carb I go. After cleaning I tested with the water hooked up and it ran just fine. Did the clean carb work or is there such a thing as to much prop. The guy that I bought it from said he messed the prop up and the one that?s on it might not be the right one for the motor. I ran into someone on the lake that has a force 85 and he said he had the same thing go wrong with his and it was the CDI and the stator. It had a burnt spot on it and was shorting out under a load.

 

[pnwboat]

Re: Force 125 that will not plain out

Cleaning the carb may have been the issue, however, the real test is out on the water. Too much prop will cause sluggish performance but I'm not sure it would cause you that much of a drop in performance. You need to find out what size prop you have.

There's quite a few problems that can cause your symptoms. One way you can check the ignition system at home is to pull one plug wire off at a time while the motor is idling. Motor should drop in RPM's the same for each plug wire pulled off. If you pull a plug wire off, and there is no change in the idle speed, that may be a sign that you have a problem with that cylinder.

 

[gonefishing1]

Re: Force 125 that will not plain out

Went out on the lake today same thing. Going to buy a book monday.

 

[pnwboat]

Re: Force 125 that will not plain out

Check to see if all cylinders are working correctly by pulling one plug wire at a time at idle.

 

[gonefishing1]

Re: Force 125 that will not plain out

I'll try that tuseday on the lake. I pulled the flywheel today to inspect the wires and everything looks brand new. Man that was fun.I noticed under the flywheel it had 2 burnt spots on it. Right by the key slot it has a round peace with two thing that felt like rubber. On the outside of it it had spots that looked like burnt spots kind of like spot welds.

 

[moparman]

Re: Force 125 that will not plain out

G.F.1,this maybe a stupid question ,but with the johnson controls did you check to see if you have wot when the control is all the way forward?I I know you said you had a carb stopped up [which will lean it out bad, don't run it to long like this as it will melt pistons quickly]but if it's running evenly under load it might be something to scope out. Just my two cents worth

 

[gonefishing1]

Re: Force 125 that will not plain out

Hi on my lunch I changed all the coils and the cdi boxs. After switching the plug wires around It's alive with power to boot. Thanks for all the help everyone.

 

[maxum_man]

Re: Force 125 that will not plain out

What do you mean by switching the plug wires around? I am having this same issue with a 92 120 hp ldrive!

 

[Hansolo99]

Re: Force 125 that will not plain out

Hi on my lunch I changed all the coils and the cdi boxs. After switching the plug wires around It's alive with power to boot. Thanks for all the help everyone.

So the pulg wires were going to the wrong plugs?

 

[gonefishing1]

Re: Force 125 that will not plain out

Hi I had a bad CDI and the wires to the CDI were hooked up wrong. It was sending spark to the wrong cylinders. After changing the CDI and switching the wires around I changed the plug wires back to 1234 and it's running fine.I had no idea what the guy did to it before I bought it to try to fix it. I hope this helps