checking compression on 1987 force 125

[gandl1988]

hello all, I bought a cajun 1987 with a 125 force outboard. I am in the process of restoring the boat, and I just got throught checking the compression on the motor. I tried to do it by the book , but when I pushed the throttle open all the way , it wouldn't let me crank it over . so I checked the compression on all the cylinders with out opening the throttle. they all check in at 145- 150 psi. my question is this . Is this sufficient enough to tell if I have good compression in all cylinders? I wanted to make sure the engine was good before I proceded with the restore. I have started the motor on the lake and it seemed to run strong. thanks for any help.

 

[maxum247]

Re: checking compression on 1987 force 125

hello all, I bought a cajun 1987 with a 125 force outboard. I am in the process of restoring the boat, and I just got throught checking the compression on the motor. I tried to do it by the book , but when I pushed the throttle open all the way , it wouldn't let me crank it over . so I checked the compression on all the cylinders with out opening the throttle. they all check in at 145- 150 psi. my question is this . Is this sufficient enough to tell if I have good compression in all cylinders? I wanted to make sure the engine was good before I proceded with the restore. I have started the motor on the lake and it seemed to run strong. thanks for any help.

When checking the compression did you pull the throttle lever out to the neutral start position and give it throttle before trying to crank the engine, if not you probably had the engine in gear, these engines are designed with a safety switch that will only allow them to crank in the neutral start position so the engine doesn't start in gear, and allow the boat take off unexpectedly?

 

[jerryjerry05]

Re: checking compression on 1987 force 125

If you got 145-150 your OK. Jerry

 

[gandl1988]

Re: checking compression on 1987 force 125

thanks guys for the help. I started the engine with the throttle lever in neutral. I would start the motor with the key. I tried to ground the spark plug wire like the book said. I cranked it about four complete turns. that is the reason I said 145 to 150,because I sometimes couldn't get the exact revolutions. because of that I checked it 4 times on each cylinder.any other suggestions would be appreciated. thanks

 

[baxtr]

Re: checking compression on 1987 force 125

Like Jerry stated, your compression is good even if it is not at wide open.

there is a neutral safety switch on the motor, directly under the throttle tower, it is just a small microswitch. When you go to full throttle,the switch releases and will not let your motor start, if you tape the switch down so it stays depressed, or just put a jumper of some sort on the leads of the switch, then you can crank the motor at full throttle, as you did before, make sure to ground the plug wires while doing this. But again as Jerry stated, your numbers are fine.