I'm working on a 1990 Yamaha Moto-4 YFM350 that has a stripped drive pinion gear (#7 on the diagram - 1990 Yamaha MOTO-4 (YFM350ERA) Drive Shaft | Part Shark) and coupler (#30). To replace the gear, I've got to get the retaining ring (#11) out. This ring sits flush with four notches 90 degrees apart. I know it takes a special tool, but I cannot find mention of this tool anywhere.

Does anyone know what this tool is and from where it can be had ... or better yet ... Does anyone know of an alternative way to get this ring out. This thing is really rusted, so I am soaking it in PB Blaster until the parts get in, but...

Thanks.

 

If you have room you may be able to use a dull punch to loosen the retaining ring.Same thing a lot of people use to remove slotted nuts on Polaris atvs.

 

I was thinking a couple of dull chisels across from one another in opposite directions... Thanks