1989 125 Force Rough at 2000 RPM

DJestes

Cadet
Joined
Jul 13, 2002
Messages
21
I have a 1989 125 HP Force Back in June just after purchasing the boat I found a wire off of a CD unit (the motor had no power then) and I re-attached it. The motor since then starts and idles fine but at about 2000 RPM the motor gets very rough and hesitates. The problem goes away once I get to about 3000 RPM. I spoke to my mechanic and he claims it is just the motor. The motor reaches WOT 35 MPH @ 5000 RPM and runs smooth. Could the CD unit be slightly damaged and causing the hesitation?
 

sony2001

Chief Petty Officer
Joined
Mar 17, 2001
Messages
607
Re: 1989 125 Force Rough at 2000 RPM

CD's either work or not. Not both. In the dark do you have electrical arching on the motor? 2000 rpm can be difficult for a lot of motors. Check timing. Can delay spark a bit with higher octane. :cool:
 

DJestes

Cadet
Joined
Jul 13, 2002
Messages
21
Re: 1989 125 Force Rough at 2000 RPM

Thanks Sony,<br /><br />I know the timing is right but not sure about the arking. What would be arking? When you say tough does that mean because of the load placed on the motor?<br /><br />Thanks
 

sony2001

Chief Petty Officer
Joined
Mar 17, 2001
Messages
607
Re: 1989 125 Force Rough at 2000 RPM

Possibly the engine is running on 3 at low rpm. Thus rough under load at 2000 and runs on 4 at 3000 rpm. Spark is grounding elsewhere than the plug then at 3000 it runs the coil wire to the plug. Thats the concept and can be approached in a few ways. :cool:
 

DJestes

Cadet
Joined
Jul 13, 2002
Messages
21
Re: 1989 125 Force Rough at 2000 RPM

Sony,<br /><br />Should I just run the motor at night and look for an ark? Do you think it may be a bad wire?<br /><br />Thanks
 

wvit100

Chief Petty Officer
Joined
May 6, 2002
Messages
416
Re: 1989 125 Force Rough at 2000 RPM

My '89 125 does the same thing. It idles good but when the RPM's start coming up there is a spot in where the motor has a shake to it, then it goes away and runs smooth. Everything runs good, all the cylinders are firing, carbs are clean, etc. It just seems to have that one spot in the RPM range where it has a shake to it.
 

Outrage 19

Petty Officer 1st Class
Joined
Jul 24, 2002
Messages
317
Re: 1989 125 Force Rough at 2000 RPM

Just a thought but could this be the transition point from the low speed jet to the high speed jet in the carb?????
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: 1989 125 Force Rough at 2000 RPM

Djestes,<br />What I did is take those crappy boots off the end of the wires that plug onto the spark plugs. I went to a Motorcycle cycle shop got some 90 Degree screw on NGK boots from them. These have like a wood screw in the middle that screws onto the wire, so it gets a good contact. They are also waterproof and used to the abuse by being used on Motorcycles. This got rid of every drop of miss that I had. You could give this a try. <br /><br />But yea, do as Sony said. Hook it up on the water muffs, run it at night and see if you see a blue spark jumping anywhere. If you do you know there is something that is broken in the cable or something to allow the spark to jump to ground.<br /><br />Hope this helps. I have an 88 Force 125 HP and Bayliner Capri 19 Foot Bowrider, and it will run right now 40 at 5000 Rpms. I am still working on getting my trim fixed, but I'm gonna try to push this boat to at least 45 if I can, lol. I am running a Hustler 17 Pitch Prop and this thing makes it jump out of the hole, also put boyeson reeds in it. They helped quite a bit to.<br /><br />She now runs smooth as a whistel at every RPM, and just goes when I hit the throttle no matter what speed I'm at, but full throttle, no where else to go yet.<br /><br />Thanks,<br />Bryan Cox<br />MTU
 

DJestes

Cadet
Joined
Jul 13, 2002
Messages
21
Re: 1989 125 Force Rough at 2000 RPM

Bryan,<br /><br />Do I just cut the boot right of the wire? What is there a screw down type of device the wire slides into? <br /><br />Thanks
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: 1989 125 Force Rough at 2000 RPM

You should beable to just pull out the wire, the boot will pop off,without having to cut the wire. Then what I did was found that I did have to cut some of the wire at the end to get back to a clean connection. It screws directly onto the wire, to give a good solid connection.<br /><br />Thanks,<br />Bryan Cox
 

DJestes

Cadet
Joined
Jul 13, 2002
Messages
21
Re: 1989 125 Force Rough at 2000 RPM

Bryan.<br /><br />Thanks,<br /><br />I will give it a shot.<br /><br />Djestes
 
Top