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-   -   Saito 125 engine bearing failure (https://www.rcuniverse.com/forum/glow-engines-114/7257801-saito-125-engine-bearing-failure.html)

mofosheee 03-20-2008 10:01 PM

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.

Flyboy Dave 03-20-2008 10:12 PM

RE: Saito 125 engine bearing failure
 
.....if you use a fuel with castor oil you will not have bearing failures. ;)

FBD.

w8ye 03-20-2008 10:18 PM

RE: Saito 125 engine bearing failure
 
Do you balance your props

liquid_TR 03-21-2008 05:19 AM

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.

mofosheee 03-21-2008 10:02 AM

RE: Saito 125 engine bearing failure
 
Thanks Guys............

The props were balanced

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

NSK bearings!

NM2K 03-21-2008 11:49 AM

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

mofosheee 03-21-2008 05:10 PM

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.

XJet 03-21-2008 08:44 PM

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!

mike early 03-22-2008 09:25 PM

RE: Saito 125 engine bearing failure
 


ORIGINAL: liquid_TR

balance your props at the tip and at the hub.

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!

mike early 03-22-2008 09:27 PM

RE: Saito 125 engine bearing failure
 
How does one know a bearing has gone bad

Flyboy Dave 03-22-2008 09:28 PM

RE: Saito 125 engine bearing failure
 
....buy castor at the motorcycle shop. ;)

FBD. :D

XJet 03-22-2008 11:50 PM

RE: Saito 125 engine bearing failure
 


ORIGINAL: Flyboy Dave

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

FBD. :D
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.

Flyboy Dave 03-22-2008 11:57 PM

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

liquid_TR 03-23-2008 02:27 AM

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.

mike early 03-23-2008 03:18 AM

RE: Saito 125 engine bearing failure
 

ORIGINAL: Flyboy Dave

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

FBD. :D

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.

mike early 03-23-2008 03:56 AM

RE: Saito 125 engine bearing failure
 
I will try this stuff:
http://www2.gpmd.com/image/k/ksfp1175.jpg

skrez 03-23-2008 06:29 AM

RE: Saito 125 engine bearing failure
 
Hi,
How does one know when a bearing has one bad?
Frank

Bone 03-23-2008 06:53 AM

RE: Saito 125 engine bearing failure
 
1 Attachment(s)
Here is the castor oil I use................

blw 03-23-2008 07:50 AM

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.

mofosheee 03-23-2008 10:48 AM

RE: Saito 125 engine bearing failure
 
Where would one obtain nitromethane of proper specification? Thank you

blw 03-23-2008 03:08 PM

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.

Flyboy Dave 03-23-2008 03:50 PM

RE: Saito 125 engine bearing failure
 
1 Attachment(s)
....I use this brand exclusively....good stuff, from the local motorcycle shop. ;)

mofosheee 03-23-2008 04:06 PM

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.

mofosheee 03-23-2008 04:17 PM

RE: Saito 125 engine bearing failure
 
P.S. No rust observed upon inspection

aa2dd 03-23-2008 07:10 PM

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

mofosheee 03-23-2008 08:16 PM

RE: Saito 125 engine bearing failure
 
Thanks Bruce:

How long and how hard did you run the ceramics before the crash?

I think it is reasonable to expect that the bearings would not survive such an event. I have also replace a few cranks, but not that often. I usually go thru bearings before crankshafts. Come with the territory. Thank you for your input.

aa2dd 03-23-2008 09:34 PM

RE: Saito 125 engine bearing failure
 


don't really recall how long i ran them, however, it was not long. I cannot say anything about life expectancy as they were not run all that long. they were in a saito 100, and an US 60. The ultra stick is just a fond memory now![&o] The Saito 100 they were in has a long history of problems. Mostly bearings. at the moment, it is down waiting for a new cam, lifters, ring and new bearings again. Last time i checked Horizon, some of the parts were on B.O., so engine is setting on shelf ... waiting. I have about reached the point of trashing it. Something has to be wrong for the bearings to keep going out. Perhaps some where along the line, I somehow managed to warp the crankcase?

Bruce

aa2dd 03-23-2008 09:36 PM

RE: Saito 125 engine bearing failure
 



ohh forgot to mention how hard they were run. Not hard. I rarely fly at full throttle, except when climbing out. I like to putz around low on the deck, and fly slow.

Bruce

XJet 03-23-2008 10:52 PM

RE: Saito 125 engine bearing failure
 

ORIGINAL: aa2dd
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.
Obviously you didn't buy your bearings from RC-Bearings.com. Pauls prices are (from memory) much more reasonable than that.

Personally I don't bother with ceramics for sport engines -- just plain old bearing-steel ones work fine and I haven't had to replace a set of Pauls yet, they seem to last much better than the factory originals.


mofosheee 04-20-2008 09:21 AM

RE: Saito 125 engine bearing failure
 
Thanks all............the bearing replacement and rebuild went excellent. And the Airplane runs great. From this experience I learned upgrade to ceramics and use fuel with castor.

JustErik 04-20-2008 02:04 PM

RE: Saito 125 engine bearing failure
 


ORIGINAL: skrez

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

Since no one really addressed this question, I'll throw out my opinion. Last Fall, I was told by a flying buddy that the bearings in my Saito 100 sounded bad. I didn't know there was anything wrong. The engine started easily, had gobs of power and was as reliable as I anyone could want. After changing the bearings, however, I could hear a huge difference. Below 3,000 or 4,000 RPM, the predominant sound I now hear is the swishing of the big 16x4W APC prop and the sound of the valve train doing it's thing. It's a remarkable difference.

Before the new bearings, there was a pronounced rattling sound that got progressively worse as the throttle was advanced. It's hard to describe, but I'll know it again when and if I come across it again. The need for new bearings was also demonstrated by showing me the end play in the crank. Grabbing the tip of the prop and pulling/pushing it backwards and forwards yielded a lot of play and distinctive clicking noises as the crank moved around. With a little guidance (from an online buddy on another site), I was easily able to install new bearings from Paul at RC Bearings and now the engine is 100%. I'm almost looking forward to the next time I have to do repair work. :)


blw 04-20-2008 03:48 PM

RE: Saito 125 engine bearing failure
 
It is fun to work on engines. Sometimes, the bearings will squeal and whine loud.

Fuelman 04-20-2008 07:50 PM

RE: Saito 125 engine bearing failure
 
I have bought many pair of bearings from Paul at RC Bearings. I use Pauls store exclusively now.
I like to use the stainless ones and have good service from them.

I have seen a lot of Saitos in the last few years have just as horrible of bearings as OS engines. Lets face it, these companies are buying poorly manufactured bearings, regardless of what company made them.

Castor helps the rust thing more than anything else, but a bearing that is going to fail is going to fail no matter what or how much oil you use.

mofosheee 05-03-2008 03:02 AM

RE: Saito 125 engine bearing failure
 
The ceramic bearing replacement worked well in my Saito.

Question. So why doesn't Saito spend a little extra money and install "better bearings in their engines?

Where I live and fly, Saito is beginning to get a "bad rap"

Customer satisfaction and reputation is on the line.

Thanks all!

Fuelman 05-03-2008 07:29 AM

RE: Saito 125 engine bearing failure
 


ORIGINAL: ****sheee

The ceramic bearing replacement worked well in my Saito.

Question. So why doesn't Saito spend a little extra money and install "better bearings in their engines?

Where I live and fly, Saito is beginning to get a "bad rap"

Customer satisfaction and reputation is on the line.

Thanks all!
I see far less Saito bearing failures than I do OS 4-stroke bearing failures. As for 4-strokes, I believe Saito has a lot more 4-stroke engines in the field than OS.
With Saito, the culprit seems to be some rust gathering on the bearings causing premature failure. With the OS, I see a lot of short term catastrophic failures, mostly with the ball cages coming apart.

Hobbsy 05-03-2008 08:12 AM

RE: Saito 125 engine bearing failure
 
Brian, I think people hear the cam followers rattle in the Saitos and panic thinking it is the bearings, I put a new jug on my 1991 1.50, I broke it tightening the carb too tight, but I left the stock bearings in, they are fine. They are still fine in my 1992 .80.

Fuelman 05-04-2008 08:25 AM

RE: Saito 125 engine bearing failure
 


ORIGINAL: Hobbsy

Brian, I think people hear the cam followers rattle in the Saitos and panic thinking it is the bearings, I put a new jug on my 1991 1.50, I broke it tightening the carb too tight, but I left the stock bearings in, they are fine. They are still fine in my 1992 .80.
You're probably correct in that Dave. Saito's do have a bit more mechanical clatter than the OS/ clones do. Novice modelers tend to be alarmed at this but they can be rest assured it is fine as long as yourvalve lash is ste within specs. To the veteran, it is a much different clatter than the whirrr or growl of a bearing going bad.

I like to set my valves following the first gallon or so on any 4-stroke to about .0015", on saito's it quiets the valve train down a bit and on all 4-strokes it reduces the amount of lifter bounce when on the trailing ramp of the cam, and increases the "snappieness" of the low-midrange throttle response.

mike early 09-17-2008 02:34 PM

RE: Saito 125 engine bearing failure
 
I changed my bearings to ceramics from RC-Bearings.com in my 125.
Later, I crashed the hell out of it. It even bent the Tru-turn spinner adapter, but not the crank.
Because I am a fool, I paid 3x more for the bearings from BocaBearings. Immediately I noticed the difference. There is a LOT of axial end play when the engine is warm. When cold, there is no end play to speak of. I imagine the bearings do not fit as snugly as they should. There is no radial end play, but I get quite a bit of oil leaking out of the front bearing. I can see the residue inside the cowling.

I was a fool to buy bearings from anyone besides Paul. I've already rectified this and have some coming in the mail.

Boca bearings does not respond to my emails asking if this type of bearing behavior is normal. Repeated emails yield zero responses. *******s.

mofosheee 09-17-2008 06:25 PM

RE: Saito 125 engine bearing failure
 


As if paying 3 times the cost is not insult to injury, how about the fact that all of the bearings come from China.

mike early 09-17-2008 07:45 PM

RE: Saito 125 engine bearing failure
 
Low quality bearings at 3x the price of good bearings and low quality customer service to boot. What a sham.


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