How to change model airplane engine bearings (part 1 of 2)

The bearings in most model engines wear out eventually but fortunately changing them is a pretty simple task, requiring no special tools.

This video shows you how to change your own bearings and is one of the informational series of videos coming from RCModelReviews.com

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  Howto & Style

[av8rc]

Kudos on an excellent presentation. If my college profs had been half as good as you, I would have learned a heck of alot more. PLEASE - do a similar video on a Saito 4-stroke. Thanks

[xjet]

Yes, I'll be doing a Saito bearing-change video soon -- I just have to convince the bearings in my Saitos to wear out first!

[Andrew Fernandez]

Thanks for the excellent video. Just one question. What are the tell tale signs of a worn bearing?

Cheers

[xjet]

Radial (sideways) play in the crankshaft when the engine is warm. ie: rock the prop by pushing on one blade, pulling on the other and you'll feel movement. Also, if you start blowing glowplugs regularly, that can be another indicator of worn bearings.

[James Morlan]

Thanks for the info. I assume "aluminium" is a regional pronunciation for aluminum? Just want to make sure it's not something completely different.

I would not even tap on the front bearing directly with a hammer - I would place your aluminum block flat on top and tap on that - no sense risking the engine at any time. :)

[xjet]

Yes, outside of the USA, aluminum is pronounced (and spelt) aluminium. You could tap the bearing in as you describe that may still apply some pressure to the inner race. The other option is to simply re-heat the crankcase so the bearing will drop straight in without any additional force being required. That's what I usually do but either way works fine.

[Films4You]

Two Excellent videos'



[Andrew Fernandez]

Just put my Saito 72 to that test and it seems to have passed.

Many thanks.

[873Mike]

Continued: I was then able to finish it off at home. I was lucky not to crack the case. When you reassemble a saito, you just need to have the piston at top dead center and have the mark on the timing wheel at 6 oclock and then your timing will be correct (its in the engine manual). In retrospect, this bearing replacement was maybe not worth the 5 hours it took me, but it was interesting to see how 4 stroke glow engines work. Would be easier on a newer engine.

[873Mike]

Thanks for a great video. I just finished replacing the bearings in a well used Saito 125 - 4 stroke. I have to say though that my experience was not nearly as smooth as yours. Everything is easy except getting the crankshaft and bearings out. Getting the new bearings in was a bit hard but not nearly as bad. To get the crankshaft out I eventually went to the hardware store and put it in their biggest vise on display and it took all my strength before it finally started to budge a little (cont.)

[wg1997fly]

Thank ya xjet. Your video helped me a lot when I took the barrings out of my supertigre st 25.

[howgas]

Thanks. This helped me so much, got my Irvine 46 successfully back in running order, thanks to this video! Helpful, clear instructions.

[Andy Jones]

That is an excellent and very informative video, many thanks , but why have 10 idiots put dislikes ??

[Blaž Petrinčič]

Nice work....

[zack reid]

Can u send me old front bearings