force 125 timing/starting troubles

I have a force 125 that I replaced the stator and flywheel 2 days ago. It cranked up just fine with the old crappy battery in it that I had to jump with my truck. When I bought a new battery today I just backfires.:facepalm: What in the world could be going on? The old battery was 1000cca and the new is 800cca, could this be it? I am not a boat mechanic but know my way around all kinds of motors. This 1 has me stumped. Any clues out there??????


Ahhhhh the stupid battery the guy gave me is only 675cca. Its a little more than half the old 1. I will exchange tomorrow with the right 1 and let everyone know. ALWAYS check for yourself for the other person may not be paying attention. Lesson learned.

Re: force 125 timing/starting troubles

I would also watch the videos, and print the carb & timing tutorial stickys at beginning of the Force Threads. I followed those directions a couple weeks ago on my Force 125 and absolutely runs perfect now...no backfiring, easy starting, great running...

Re: force 125 timing/starting troubles

Your motor should turn over with a 450cca. The bigger doesn't always mean better.
There is a different problem than the battery.
Check all the connections?Clean/rebuild the starter.
Do a compression test.Low comp on 1 cylinder can cause problems.
Adjust the air screws.

Re: force 125 timing/starting troubles

675 CCA battery is not the problem. Although I recommend you might as well get a bigger one. Anyways, what do you mean by backfiring? Out of the carbs or the exhaust? Does it even ran and idle? If not follow mghoag lead by reviewing the synch and link and also the timing video. If problem persists post again.

Re: force 125 timing/starting troubles

I will defiantly start with cleaning carbs and timing. Thank u all for the info.




I cleaned the 2 carbs and fuel is definitely not the issue. I am gonna get the timing checked tomorrow. The backfiring comes out the exhaust. When I pulled the plugs they were wet like its a late fire or something. After I replaced the stator and flywheel I jumped the old battery with my truck and it fired right up. When I changed the battery to the new 1 is when the problems started. Now it wont even start. Starter hits the motor sending in going and...bang, backfire out the exhaust port. Due at the lake aug 3rd and this is not going too well. :grumpy: I just hope timing may fix this. I will keep you all posted.

Re: force 125 timing/starting troubles

Just changing of the battery should have not changed anything with the timing and firing unless there is some lose connections with the battery cables, both the negative and positive. Your description of backfiring to the exhaust sounds more of an engine trying to start but can't due to lack of cranking speed.Ensure cable connections are shiny clean and tight both on the battery end and to the engine block and starter solenoid.

Re: force 125 timing/starting troubles

The new info you posted,sounds like it sheared the flywheel key.
Remove the top plug, insert a small screwdriver in the hole.
Turn the flywheel until the screwdriver stops comming out.
That's TDC Look at the front of the motor,above the carbs.
There should be a timing mark.
It should be aligned with the single hash mark on the flywheel.
There are 3 other marks,disregard them for now.
Post the results????

Re: force 125 timing/starting troubles

You are correct jerryjerry. Are you telepathic or something? Lol. I pulled the flywheel earlier on a hunch and that is exactly what I found. First I pulled the top plug and got the piston to the top stroke, TDC, and just looked for my marks on the flywheel. The mark was way off. I am gonna get a new key tomorrow and I will let you all know how it goes. Very much appreciate the advice on the sticky threads too. Got everything synced up to the point of needing the key for timing. :joyous:

Re: force 125 timing/starting troubles

I got the new key in and vrooommmmmm, purrs like a kitten. Still not charging though. I ohm'd out the rectifier and the thing was toast. Lol. At least it is an easy fix and I should be good to go. Thanx for all your help everyone. I will keep you informed on how it goes.