Saito 125 engine bearing failure
 

Hi All:

Runnng a new Saito 125 with a 16X6 APC prop. Experienced two consecutive engine bearing failures after going thru 1 gallon of 20/20 power master. Running on the rich side and applying generous amounts of after run oil after the flying day.............any thoughts. Thank you.

RE: Saito 125 engine bearing failure
 

.....if you use a fuel with castor oil you will not have bearing failures. ;)

FBD.

RE: Saito 125 engine bearing failure
 

Do you balance your props

RE: Saito 125 engine bearing failure
 

Dave, his problem seems to be mechanical, not related to rust.

Ive also suffered a SKF 6903 bearing failure on my saito 100, as it had just 10 tanks of flight on it. (I use castor oil in my fuel). One of the balls disintegrated on the last start of the day. Fortunately I immediately shut it down to prevent further damage. The bearing was a little loose to my liking before installation. Now Ive got a nice NSK 6903 with nearly zero radial play and things are fine again..

m ofoshee; choose a bearing with a minimal radial play and balance your props at the tip and at the hub. Using 3 to 5 % castor oil in the fuel will help protect your rear bearing against rim and cage rust, and you wont need to put any mineral based after run oil at the end of the day; if you run your 125 at least once every 2 weeks.

RE: Saito 125 engine bearing failure
 

Thanks Guys............

The props were balanced

I'll try the 3-5% castor oil.

NSK bearings!

RE: Saito 125 engine bearing failure
 

That little bit of castor oil in the fuel does make a difference when it comes to ball bearing life.


Ed Cregger

RE: Saito 125 engine bearing failure
 

Despite all the warnings from Saito & Horizon about not attempting a repair on the Saito's, I have decided to replace the bearings myself (with ceramics) rather than send the engine to Horizon and wait up to 3 weeks for a return. Repairing these engines is quite simple. Thanks all!

This forum continues to be a great resource.

RE: Saito 125 engine bearing failure
 

Make sure you don't spend more than you need to on those ceramic bearings. Go to [link=http://www.rc-bearings.com"]RC-Bearings[/link] and you'll find an excellent product at a stunningly low price.

Plus the customer-service is second to none!

RE: Saito 125 engine bearing failure
 

What exactly does this mean?


I have 3 gallons of Wildcat 20/20 and do not want to let it go to waste, so is it a good idea to add an extra 2% of Castor? Where does one buy Castor alone?


Thanks!

RE: Saito 125 engine bearing failure
 

How does one know a bearing has gone bad

RE: Saito 125 engine bearing failure
 

....buy castor at the motorcycle shop. ;)

FBD. :D

RE: Saito 125 engine bearing failure
 

But be careful, some castor (usually sold for bikes or karts) is designed solely for mixing with gasoline and won't mix with methanol very well at all.

RE: Saito 125 engine bearing failure
 

....there is only one type of castor oil available on Planet Earth....

....this oil will mix with gasoline (petrol) or methanol....just fine. ;)

FBD. :D

RE: Saito 125 engine bearing failure
 

castor (correct me if Im wrong) have a hard time mixing with very high concentrations of Nitromethane - which the fuel mfgs use chemical suspensers in the mix to hold them nice and mixed.

Balancing the prop at the hub means, after balancing the prop at the tips, you can put the prop to a 13:00 - 19:00 position on a sensitive balancer such as dubro balancer, and watch which way it sways. accordingly, add some weight to the light side of the hub (center). This usually goes for only wood props.

RE: Saito 125 engine bearing failure
 

http://www.motorcycle-superstore.com...cle_Oil_--.jpg
Can I assume this, and stuff like it, are 100% castor?


This stuff can be found at vitamin stores:
http://www.zooscape.com/dataimg/zoo0...g/428131_b.jpg
Thanks!

Edit: I see that medicinal castor is undesirable.

RE: Saito 125 engine bearing failure
 

I will try this stuff:
http://www2.gpmd.com/image/k/ksfp1175.jpg

RE: Saito 125 engine bearing failure
 

Hi,
How does one know when a bearing has one bad?
Frank

RE: Saito 125 engine bearing failure
 

Here is the castor oil I use................

RE: Saito 125 engine bearing failure
 

Not wanting to appear to be getting into a castor fight, but I do think that any castor is okay. I have a friend who mixes castor from the drug store into his fuel and he hasn't had any problems.
When W8YE was visiting this area, we changed our friends bearings in a Saito .80 after they went bad in a very loud way. We found a lot of metal throughout the engine from the retainer that went bad, but absolutely not a speck of rust anywhere in the engine. The bearings themselves were shiny like new. I'm 99% sure this guy mixed castor with Omega 15% fuel. He isn't known for any particular care of his engines other than adding a couple of ounces of drug store castor.

Having said that, I would prefer using something like Sig castor, but I wouldn't hesitate paying more for the pharmaceutical stuff if that is all I could get at the moment.

RE: Saito 125 engine bearing failure
 

Where would one obtain nitromethane of proper specification? Thank you

RE: Saito 125 engine bearing failure
 

A speed shop would be a good place to ask. Some motorcycle shops. We have those and an APR shop here if I ever want it.

Edited to add: I looked under 'racing' for Napa, Ca. and found a lot of hits for speed shops.

RE: Saito 125 engine bearing failure
 

....I use this brand exclusively....good stuff, from the local motorcycle shop. ;)

RE: Saito 125 engine bearing failure
 

Thank you BLW and all responders........ I should have known better than to clutter this board with that question and researched this myself. So it's off to Sears point I go. The daze of $23/gallon of fuel are soon son ending for me as I have been threatining to go exclusively gas for a while, but I still have a couple of nitro models that I like.

"blw" Are you the author or supplier of the "the complete Saito note's" on this forum? Excellent read and kudo's to who ever! I studied it intensely.
Neurotic and very nurturing and caring of my engines (balancing, running in, richness, proper prop, cooling, after run oil and everything else I could think of) I am still perplexed on the extremely rapid failure of this GREAT RUNNING Saito 125 engine bearings.

On the subject of ceramic bearings...........should I go full ceramic or ceramic balls/steel races? Various suppliers with different options and claims. Boca bearing company is pricey but has specific packages for each model. I want maximum longevity.

RE: Saito 125 engine bearing failure
 

P.S. No rust observed upon inspection

RE: Saito 125 engine bearing failure
 

Ceramic bearings are okay I guess, but if you dink the engine, chances are good that the bearings will be damaged. I replaced bearings in my Saito 100 with ceramic, and it ran just fine till I had a mishap with the ground! It was not a hard crash and did not do any damage to the plane to speak of, BUT, it trashed the bearings. the ceramic balls chipped, busted or what ever you wnat to call it. I figgered that i spent approx 90 bux for nothing but trouble.

Bruce