1985(?) Force 125 backfiring when starting

Hi all,<br /><br />I am having problems starting my Force 125 outboard 2 cycle. I think it's a 1985 or 1986. When I try to start it it backfires I believe out of the exhaust. I recently acquired this boat and started fixing it up. It started fine when I first got it. I have changed out the gas (gas was old) and changed all the spark plugs in it. Ever since then it just backfires when I try to start it.<br /><br />I am thinking that either the timing got messed up when playing with it or possibly I connected the sparkplug wires wrong. Does anyone know the firing order and how the timing should be set on this? Any help would be greatly appreciated as I would like to get this out on the water this year without going broke.<br /><br />Thanks in advance.<br />Jim

Re: 1985(?) Force 125 backfiring when starting

Yes, Jim. It sounds like you may have two plug wires switched. The firing order is 1-3-2-4.<br />Did you mess with the timing linkage? If not, it should track with the throttle just fine. These hardly ever 'loose time', the way they are designed.

Re: 1985(?) Force 125 backfiring when starting

I did play with the timing a little thinking that was it. I am new at this and don't know much about motors. When you say the firing order should be 1-3-2-4, how do the wires hook up? I would guess that the top coil goes to the top plug, then the 3rd coil from the top (for the 3 in the firing order) goes to the 2nd plug from the top and so forth. Is this correct?<br /><br />Thanks for the help so far

Re: 1985(?) Force 125 backfiring when starting

signus,<br /><br /> I have a 86 125 and my sparkplug wires are all a different length. The longest one goes to the bottom plug the shortest one to the top plug. And so on.

Re: 1985(?) Force 125 backfiring when starting

signus-x<br />I have an '86 125 HP Force and it back fires sometimes when I start it, but not to the severity it once had. Once you get your motor started and it runs fine after warmup, I would not be concerned too much. Once you get it started, if there is excessive smoke coming out of the exhaust ports, it's getting too much fuel at startup. As for my engine, if I set the throttle (gear lever in nuetral) too high, the engine will 'pop', backfire and run rough. If I back off on the throttle and give it a quick choke while turning the key, the motor will eventually start with little or no backfire. This is my own experince. Your engine may vary. I've consulted a Force expert mechanic of why the engine was so hard to start (not that it was free-the mechanic was relacing a stator at the time). First, the carb settings were off, including the choke plate settings. Secondly, he performed a 'leak test' in each of the cylinders. #2 and #4 cylinders were leaking 90% due to heavy carbon buildup. The piston rings were not flexing the way they should due to the carbon. Yet what was surprising was that the compression range in the four cylinders was from 105 to 115 psi. The mechanic recommended a decarb. The decarbing helped make starting easier along with the carb adjustments.<br />Hope I didn't get too technical on you, but I would suggest taking your engine in to have the carbs checked/adjusted along with a leak test and a decarb. The more you know about your engine, the better for solving present problems and minimizing future ones.

Re: 1985(?) Force 125 backfiring when starting

I think I am going to take it into the shop. I'll probably play around with it this weekend before taking it in though. The local shop is backed up for about a week and a half. Some of the tests mentioned (leak test and compression test) I don't think I will be able to do on my own since I probably don't have the correct tools.<br /><br />I think I may try to take the carbs apart and clean them really good and see if that help. If worse comes to worse I'll just have the shop put it all back together. I do have a service manual so it shouldn't be too hard.<br /><br />As far as the spark plug wires and the lengths go, mine are all different just like yours revertmastec. This leads me to believe that the shortest one should go on first plug, 2nd on 2nd and so forth.<br /><br />Also I wanted to say how much I love this board and thank everyone for all the help. This board has been very helpful for me...the newbie boater. Not just with posting but reading all the other posts is some great education.

Re: 1985(?) Force 125 backfiring when starting

Hi,<br />My Force 125 regularly "sneezes" when starting hot or cold,then runs fine,but I wouldn't call mine a backfire.

Re: 1985(?) Force 125 backfiring when starting

Yes, they all sneeze a bit. This is why I quit reccomending Boyesen composite reeds on the 85-150HPs. This sneezing can damage glass reeds.

Re: 1985(?) Force 125 backfiring when starting

I thought I'd give you all an update on this.<br /><br />I found that the motor was 180 degrees out of time. Since we did have it in time before I was kind of shocked at this. I found that the flywheel key was gone and this was causing the flywheel to spin out of time. Last night I took the flywheel off and put it back on time...it fired up right away. Since I didn't have a replacement key it lost time again, but I'm going to pick up a key today.<br /><br />Thanks again for all the help!