Yes, pretty hard to break a steel cage... maybe bearing was defective.

Maybe it's possible the spring came out of the seal and is stuck in the bearing, making it look broken?

I managed to ruin a good Koyo crank bearing early on when I was more incompetent than now by crushing the steel cage.  I think I got too aggressive with the drywall screw removal method.  $35 and more hours tearing down and scraping off what was a perfect application of Yamabond.  But in the end I got it right, you will too!

Heres some pictures of the bearing

Yep, something is wrong. Looks like the cage got pushed in at one spot?

BTW, instead of the drywall screw method of seal removal, picks work FAR better.

www.harborfreight.com/mini-pick-and-hook...E2WzhQBoChlkQAvD_BwE

I’m struggling with deciding whether to order the same rebuild kit I got before or to order a new bearing from somewhere else. The bearing that came with the kit before were Koyo bearings. I don’t think that it was defective. I must have damaged it somehow myself. Does anybody recommend a source for bearings?

Also, I was thinking about replacing the piston rings, since I didn’t replace them the first time, but I’m having a hard time finding them. Does anybody know where I can get them?

Good deal that you found your engine noise quickly.  You said your self you couldn't get the seal in all the way and beat on it pretty good. Noise started right after that? Can't tell by your picture but case doesn't look good either where the seal goes. Maybe it's the angle of the picture? Did you check the seal you removed and see if the inner spring came off into the bearing?

I would buy the bearings from Rocky mountain ATV. they stock them. Or if you have a  local Industrial place you can get the bearings there. I have a local store called Applied Industrial i get all my bearing from. 1/2 the price of Partzilla, same Koyo bearings. Just type in 6205 C4 in google. Amazon has NTN 6205 C4 bearings for $ 21.00.  For the amount of labor you will have re doing the bearings i would stick with Rocky mountain and just buy the yamaha bearings and crank seals. Your not talking that much more money and you will get them fast. Good luck the 2nd time around. 

Same with your rings. type in the stock part number into google for the ring set you need. You should see some listed either on e-bay or someone that has NOS parts. Don't remember if you said what bore size or piston you have in your engine? 



 

Contact Enduronut for rings.

Best deal on crank bearings and seals for a 175 is the All Balls 24-1073 kit from ebay.  Just over $40 for everything.

The ones I've bought have correct Koyo bearings and OEM brand seals...  mag side is the better dual lip/dual spring type. 

 

Thanks Mark,

Just so I'm clear, the 24-1073 kit is for the 77 IT175, that's why it has the dual lip seal. But the bearings will work on the 75 DT175, correct?

Hey MarkT will that kit fit my AT2 I know the seals will work what about the bearings?