engine bearings source

ran49 · #1 06-30-2008, 11:33 PM

I managed to break my 70cc boy go fast down except for taking the crank apart.Looks like it wasn't meant to be taken apart.the large lower pin holding the two halves of the crank together with the roller bearing in the center almost look brazed on.Anyway I plan on replacing the outside crank and jack shaft bearings
On my motor they are both 15mm bore 35mm O.D. and 11mm thick.The jack shaft bearing are sealed and the crank bearings are open.both are marked 6202.Any good source to purchase these.Ron

misteright1_99 · #2 07-01-2008, 12:00 AM

Maybe this thread might help.........

http://motorbicycling.com/f30/bicycl...-down-391.html

wildemere · #3 07-01-2008, 12:41 AM

Take a sample to a bearing shop?

Popular Metric Bearings

They are available in open shielded and sealed.

Make sure you get the same type.

**Bikeguy Joe** · #4 07-01-2008, 07:28 AM

Any local bearing house will match them up.

Have you tried Boca Bearings :: Miniature Bearings for Hobby and Industry :: Steel and Ceramic Bearings ?

ran49 · #5 07-01-2008, 10:24 AM

Thanks for the links guys.
I did read Norman's tear down thread or I probably would never have got it apart.there seems to be a lot of slop in my lower bearing and while I'm in there I would like to replace it.I noticed Norman seemed to leave it alone and that worries me.I have found in the past that just because I can take something apart doesn't mean I can get it back together.Here's a pic [IMG]

[/IMG]
You can see the heat discoloration.I'm guessing they heated the wheel to ease installing the shaft?Anyway anyone ever take this thing apart.Ron

misteright1_99 · #6 07-01-2008, 10:50 AM

I'm glad Normans post helped. He has alot of good information, along with pictures, an awesome member for sure. I have seen things like that, they heat up one part and cool the other, then when they are together it is like they are pressed together. I would PM him and ask him, cant hurt.......

George....

**Norman** · #7 07-01-2008, 08:12 PM

I stoped short of takeing the crank apart as I would have to tear up the main bearing to get the crank apart, I think your right on heating up the flywheel and cooling the crank pin. Another problem is getting it trued up after it together so I left it the way it was.
Norman

**Bikeguy Joe** · #8 07-02-2008, 07:48 AM

Getting it trued up may be easy...if any does tear it apart here's how to "align" a pressed up crank pin.

SERIOUSLY- If you need to align the two flywheels, use a hammer. If you need to true them up for run out, use a hammer and a hardwood wedge.

If anyone is interested in more on this, look it up in the Harley Davison shop manuals.