I have a 125 force outboard when its in neutral it revs up fine, but when in gear top speed is 15 mph any idea

Question

1986 force 125, duel carbs new coils ,prop looks good,water flow good,compression good

Answer 1

do you have a water sepperator ?if you do change it and is it the right prop on the motor?

Answer 2

Try checking your ignition system. I sounds like it may not be firing on all cylinders.  You might have to replace the cd box and trigger control.

Answer 3

The first thing to check is make sure that it has spark to all cylinders.Then check to be sure all your spark plugs are good.You say that your prop looks OK,are you sure it's the right pitch prop for your boat?You do not say whether or not the engine is revving up,so I am going to assume no.You should also check your fuel pump diaphragm and also the anti-syphon valve on your fuel tank.(If you have a built in tank)These are the things that will cause the problems you are asking about.If all of these are alright then you will need to do a more thorough check of your electrical system.Good luck.

Answer 4

This engine had a history of the #4 cylinder failing.  A quick compression check should tell the story, but you said it's good.....so the only other place to look is the lower unit gear-case.  If the bearings have failed you'd get the same problem.    Of course, make sure all 4 cylinders are firing, a simple spark checker, Champion spark plug makes one, is best.  Don't pull the wire loose and ground it to the block, unless you want to buy a new pulse pack.

Answer 5

classic symptom of clogged hi-speed jets.

If you have good compression & spark on all four, rebuild the the carbs using new kits.

Answer 6

Could also be youre timing advance?