[cloudniner]

My method.

I have a old toaster oven in my workshop to heat the engine. The crank and bearings usually end up just falling out when heated to 200F to 225F. If the front bearing refuses to come out a wood dowel from the rear will do the trick. The back bearing if stuck usually comes out with a smack on a piece of wood.

When putting in new bearings.

I put the bearings in the freezer or out side in the winter, the crankcase goes in the oven at 200F. Bearings end up falling into place. Then heat the crankcase with bearings in place and the crankshaft goes into the freezer. The crank will usually fall into place.

No hammering usually required.

[Flyinbullmax]

Unfortunately these links are dead, so if you search on google you should find some.

[moo]

Club Saito:
http://www.rcgroups.com/forums/showthread.php?t=1075443

[floyd]

I never freeze or heat any of my engines or bearings before an installation. Before you heat or freeze see how tight they fit by hand. They should need to be pressed in. If you run the motor with a bad bearing you can do extra damage. I've seen spun bearings in the crankcase, and on the crank. Plus the next weakest part is the lower connecting rod bushing. I've seen Saito's knocking at idle because the rear bearing was so bad the connecting rod hit the channel in the crankcase. Cheers Floyd

[hitechflyer]

Originally Posted by nahashmi

A helpful link. I might have to work on 2 of my engines but not sure what is the actual problem with them. One of them sounds OK so I assume bearings are alright. It does start up but does not respond to the needle settings. Gets too hot and then shuts down. At that time there is absolutely no compression that can be felt by rotating the prop. After it cools down I can feel the compression. Can anyone help me in understanding what's wrong with them ? What to do ?

Thanks.

Tighten your cylinder head bolts, when your motor warms up everything expands and you lose compression.

[Raptor30V2]

I use a heat gun to heat engine case bearing fall out easy. No need for torches or baking it in the oven. After all its not a cake.

[Raptor30V2]

If you hear any rattle at idle the bearings ahould be changed . This noise creeps up slowly so some people might not notice it.

[Rod Kelln]

Agree totally with Kopter that beating on the crankshaft to remove the prop drive washer from a collet type set up is a bad approach. All my pylon racing engines are collet type and I use a heavy duty battery terminal puller to "pop" off the prop drive washer. Princess Auto has this great tool for $13 CDN. No doubt you will find other uses for it as well. Once you have pulled the drive washer, simply slip off the collet and push out the crankshaft, but if it resists, then can use a block of wood and tap on the end, or, put on a spinner nut (to protect threads) and tap on the end of that directly.

[Rod Kelln]

There have been several comments about installing bearings but thought I would add one additional aspect about ensuring smooth running bearings. After installing the front and rear bearings and crankshaft, put on the prop drive washer and install a prop plus spinner nut. Spin the prop and see if it spins freely or if there appears to be any "stiffness" in the new bearings, and there often is, i.e., inherent preload. Regardless, warm the case with your heat gun and then give the spinner nut a hard rap with a block of wood or a mallet, and try spinning the prop again. Repeat as necessary until you have a free spinning prop. Then assemble the rest of the engine.

[Kl1952]

Thanks ! and Thanks ! It is what I am looking source for my Saito FA72 bearings.