Bearing removal

[Banshee330]

Well I finally had some time today to work on the motor. Cleaned a few gaskets . I got the 2 bearings out of the case the you can’t press or knock out. Just asking how do you guys normally get the bearings out of the case.

[2ndmoto]

Heat or bread crumbs and a punch or blind hole bearing puller

[The norm]

You can put the case halves face down in the oven at 200°F until you hear the bearings drop out.
Loren

[broken1]

I picked up an old nasty used oven for free about 5 years ago for doing exactly what Loren described. It's also handy to have a shop oven for curing painted or powder coated parts.

[Banshee330]

Any recommendations or tips and tricks on removing the counter balance gear and bearing, any advice would be appreciated.

[The norm]

So you have to get a very clear accurate scribe line on the counter balance gear or you will cause a big vibration issue. I have rebuilt a couple with success so it can be done. I use a center head for my combination square to scribe a line down the center of the gear and end of the shaft. Then I rotate the counter balance 45° and scribe a line from the edge of the gear to the center of the first line. That gives me three lines to get the gear on correctly. The line at 45° also prevents you from getting the gear 180° out. I set the counter balance up in my press and then warm the gear with a small propane torch and gently press it out. Once warm it pretty much drops off. The bearing is pretty much a slip fit so it should come right off. Then I let everything cool to room temperature. I put the counter balance in the freezer overnight.  Gently clamp the counter balance in the vise using cardboard or rags as softeners. Heat the gear to 200°f and drop it on. You will have about 10 seconds to get it timed correctly so don't waste time. If its off just give it a twist to line it up.
Loren

[The norm]

[Banshee330]

Great information Loren, thanks!

[broken1]

So you have to get a very clear accurate scribe line on the counter balance gear or you will cause a big vibration issue. I have rebuilt a couple with success so it can be done. I use a center head for my combination square to scribe a line down the center of the gear and end of the shaft. Then I rotate the counter balance 45° and scribe a line from the edge of the gear to the center of the first line. That gives me three lines to get the gear on correctly. The line at 45° also prevents you from getting the gear 180° out. I set the counter balance up in my press and then warm the gear with a small propane torch and gently press it out. Once warm it pretty much drops off. The bearing is pretty much a slip fit so it should come right off. Then I let everything cool to room temperature. I put the counter balance in the freezer overnight.  Gently clamp the counter balance in the vise using cardboard or rags as softeners. Heat the gear to 200°f and drop it on. You will have about 10 seconds to get it timed correctly so don't waste time. If its off just give it a twist to line it up.
Loren

You attempted this without the special Honda jig that was purchased directly from Honda & only available for use in Rancho Cucamonga California?

[The norm]

Yup

[broken1]

Yup

Good man!

[Banshee330]

Used this little jewel to remove the tiny clutch shaft bearings! Son asked last night, dad how comfortable are you building this motor, I said not sure never built one before.

[Banshee330]

Having a hard time finding this little spherical roller thrust bearing on or near the clutch. Any ideas where I can find this bearing?

[The norm]

Rockymountainatvmc.com has them. Go to the oem section and run through the drop downs. Select 1989 trx250r, then select the clutch parts schematic. It's #24 part #91001-147-003.
Loren

[The norm]

Don't worry too much about "knowing how" to build a 2stroke engine.  I didn't know how until I did it. I'm not afraid to take apart any engine. You have to be very methodical and organized. When you take something apart it's good practice to label things and to lay them out on your bench in the order they came out. Take lots of pictures and by all means ask this group anything! No matter how stupid you might think the question is, we have all probably asked it when we were learning.
Good luck with the build and most of all have fun!
Loren