[mrrandyman]

I wanted to post this from rcmodelers.com on how to change the bearings in your engines.
There is some very good information there for everyone.
Randy

http://www.rcmodelreviews.com/bearings.shtml

[Dave Holmes]

The whole site looks really worth while! Thanks for pointing it out.

[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.

[Skidoo55]

I found that site some time ago, and used his process to remove bearings and crankshaft in one of my engines. Check out his review of the SK90. I have an SK70, and for the money it seems like a decent motor with TONS of power.

With respect to the overheating engine thread, I would suspect that your engine is drawing air from somewhere other than the carb and running too lean. Could be the front bearing or the gasket on the back of the motor. Pour some fuel into the carb and see if it drips out anywhere. You may need to set the motor on the back cover, with the crankshaft vertical to see if the gasket is leaking.

The other possibility is a gummed up carb...

[DO335]

Originally Posted by Skidoo55

Could be the front bearing ...

Defintiely the possibility of a leak. However, with all due consideration, it would not be from the front bearing. The bearing is not a seal and does not seal anything.

Many engines, my old Webra and HP GOld Cup included, did not even have any cover over the front of the bearings They are totally open.. That cover is only to keep debris out of the bearing. It is not a seal.

The seal at the front of the engine is formed by the fit of the crankshaft in the crankcase housing. If the fit cecomes excessive, you will develop a leak there and indeed fule can come out.

you will also find a small shaft or channel going from the carb to just behind the rear of the front bearing. This is intended to be a passage way for excess fuel that leaks out the front to be drawn back into the enine via the intake while it is running. If it gets clogged, which can easily happen with old, gummy fuel residue, you may also have an apparent leak as the excess fuel coming out the front can no longer be drawn back in.

[Flyinbullmax]

Here is a good one for Saito, too.

You Tube

You Tube

An other one for OS fourStroke

You Tube

You Tube

And before reassembling my engines I soak them overnight inthe garage in my Crockpot with prestone in it. Once well rinced you will find that it really brings back the youth out of it... Oh, and make sure the crockpot won't be used for cooking food after....

[mrrandyman]

Great info Flyinbullmax. Thanks

[chuebner]

Great info here guys.... I hope you guys don't mind but I made this a Sticky in the Engine forum for all to use for easy referance.

Thanks

[Kopter]

Not the smartest way to remove the prop drive washer using a hammer. Kippy is beating the bearing balls into the races. If you plan on tossing the front bearing not so bad, however with care a front bearings last a very long time, several times longer than the rear bearing. The prop driver collet by nature is designed to be pulled after the drive washer is removed using a puller and that is why it is slotted. The removal of drive washer removes collet clamping action at the crankshaft. Some front bearings have rubber seals that don't like torches. Get a drive washer puller is my thinking. Then again, I'm just a kid, what would I know?

[Generalwolfe]

If you're looking for bearings you might want to check out http://www.rcbearings.com . I recently swapped out the bearings on an old SuperTigre and ordered from RCBearings. Their service was prompt and when I discovered that one of the bearings they sent was the wrong size, they sent a replacement with no hassle or additional cost.