1997 force 125 thumping

[dave0120]

My 125 has started thumping when under way. It is normal to about 3500 rpm then every few seconds it makes a audible bump as well as it seems to jerk a bit

 

[las]

That's what mine did! Worn clutch dog and gear.
Found this video that shows it pretty clear

 

[dave0120]

Thank you very much for your response I will get parts ordered.

 

[las]

Your welcome.
By the way it's not my engine in the video, just one I stumbled across when I had the same problem.
I hope you get it sorted! But it's not a small task no matter how you go about it.
If you end up changing the gears and dog you would have to shim the gears again and that requires a lot of special tools for the specific engine.

 

[dave0120]

I ain’t scared

 

[jerryjerry05]

Is it a 125?? they didn't make a 125 in 97???
Some gear cases can be rebuilt without shim tools.
Just gotta figure out the model, year etc.

 

[foodfisher]

The dogs can be ground square again.

 

[dave0120]

Nice catch Jerry, it is an 87

 

[jerryjerry05]

The 87 will need special tools to rebuild.