Kmot

My Feedback: (24)

Oh boy.

Wel, if you go through this thread, you will see that Bill has addressed this dozens of times.

William Robison

My Feedback: (3)

Bob:

Quote:

ORIGINAL: N1EDM
...I just checked my Saito manual (2004) and they say that the gap should be .002 to .004 (0.03 - 0.10 mm) which is a little looser than the .0015 that I set my valves at using the cigarette wrapper...

So I'll address it again. The engine is metric, the metric specification takes precedence over the rounded inch measurement. 0.03 mm is 0.00118 inches, well below the 0.0015" I say to use. The 0.0015 inch clearance is 0.038 mm, well within the 0.03- 0.1 mm specification. Just for general information, 0.002" is 0.0508 mm, 0.004 is 0.1016 mm.

Bill.

N1EDM

My Feedback: (2)

Ha, thanks Bill... I should have run the numbers myself before I opened my big mouth.

Thanks,

Bob

JettPilot

My Feedback: (6)

I have ordered the Ceramic bearing set for my Saito 82 from RC-Bearings as William recommended. You guys also talk about not "tapping" them in as it might damage the ceramic bearings... Does that mean these ceramic bearings are very sensitive and may be damaged by prop strikes, or nose overs ?

JettPilot

DandGMartin

JettPilot, I got a set of ceramic bearings and was cleaning up the shaft to slide the rear main onto it, in one trial fit I pushed it on too hard and could not pull it back off. I held the bearing between my left thumb and forefinger and gently tapped with a small block of wood on the end of the shaft. Then I could feel a slight click when turning the bearing. I installed it anyway, and needless to say it didn't last very long. When I replaced it I made sure that it slipped onto the shaft freely and heated the case then the bearing dropped in the case easily. I doubt that a prop strike at idle would damage a ceramic bearing but I'm fairly sure a nose first landing would.

Garthwood

Mr. Robison...................To-day I received back my Saito .72 from Horizon Hobby that I sent down for check up because of loss of compression. I was told that I needed to replace both bearings front/back. They said the rear bearing was'nt even turning on the crank and the front one was bad. The exhaust valve in the cylinder was leaking so they polished it up. The compression problem is fixed and they replaced both bearings. Both ball bearings were returned back to me. They are both sealed BB. I see no sign of rust and or damage, and I feel that the tech. is giving me the gears regarding the BB. Both BB turn and they feel smooth with no binding. I have seen badly rusted BB before, these bearings look just like new.

I am sure you have come across a bad front bearing and a rear bearing that does'nt turn on the crank, perhaps you can explain to me what they should look like, because I am baffled with their findings and with the returned bearings. Because I do not see anything wrong. The tech. did a visual observation like I did. My visual observation, checking for sign of rust, sloppy movement side to side, binding and what you guys call skidding because the bearings are sticking, am I right ?

Appreciate any comments, because this is the only way that us who are not as experienced as you are can learn from the master himself.

Regards
Charles............

w8ye

My Feedback: (16)

Charles,
You could very well be correct about your conclusion?

Your ideas of evaluating a bearing are pretty good.

Hobbsy

My Feedback: (102)

Garth, that is a pretty much the standard line they give people, now think about this, if the inner race was not turning with the shaft, the shaft would be burned and blue from getting hot.

Garthwood

Jim.................Thank you for your comment.

Charles.

Garthwood

Hobbsy................thank you, thank you, thank you......................I know that the rear bearing was turning on the crank, because prior to sending it to Horizon I removed the back plate to have a look, it was clean, turning and no sign of rust. I should take a picture of the bearings to show them to you guys, just the way they sent them back to me.


Charles.

RVM

More questions about my Saito .82

I flew it today and am still having a hard time tuning the high speed needle on my .82. I leaned the low end in a lot, and that seemed to help with the high end a bit (transition is getting a lot better, as well as the idle), but it still isn't tuning quite how I'd like it. I did notice the regulator was leaking air again, so I fixed that (for the most part). I'm still peaking around 9150 (with no air leak) with an APC 15x4w and I've got a gallon through the engine now. I'm not sure if I can still lean it further (needle is still out about 2 - 2.5 turns), or if it's just a "weak" one. I turned the needle in a full turn and it had virtually no effect on the engine. RPMs stayed almost absolutely constant. I turn it in just a little bit farther than that and it starts to lose power. It does this with or without the regulator, though I'm going to try without the regulator again to see what happens.

I am waiting about 5-10 seconds between each needle change.

I'm going to up the nitro soon, but I am using 20% now and figure (based on all the numbers I've seen here) that I should be peaking around 9400-9500 with that prop. There are people with less nitro, more elevation and less fuel through the engine getting more than that.

I tightened up the valves and set the clearance to a tight fit on the feeler guage and that didn't make any difference.


All of this said, it runs extremely well, very smooth (for a 4-stroke, and contrary to what I've heard about this engine and its tendency to vibrate) and very reliably. I just can't get it tuned like I could my .91. Blargh.


Thanks. [8D]

Garthwood

Jim..........Hobbsy...........here's a picture of the Rear and Front bearings that was in my Saito .72........This engine had at least 90-100 flights. The engine is about 3.5 yrs old. Fuel Power Master 15% Nitro 20% all synthetic oil. Engine emptied from fuel and after-run oil of 50%Mystery Marvel (or ATF) and 50% Air Tool oil added after flying sessions. Clean as can be, don't you think so ?
Please comment.......

Charles.

w8ye

My Feedback: (16)

There's not much rust

But those front bearings can foul up and not show anything on the outside.

You should try turning the bearings and see how the bearing feels?

Garthwood

They feel smooth and no drag. There's no sideways slop. Maybe I should soak them in some kind of a solution and let them sit for a while and see what comes out. You ever tried to open one of these up ?. I'm kind of curious to see the ball bearings inside. I think it's the only way to find out.

Charles.

w8ye

My Feedback: (16)

You can take a scribe or ice pick and pop the seals off but you cannot get them back in.

sundancer007

Those bearings are due for replacement at the amount of time they have on them. But from this perspective, its hard to see any pitting or wear on the inner and outer races without a microscope.

bohelle

Hey Guys,

New to Club Saito. I just bought an old Saito FA-65 with air bleed carb off of e-bay. This is my first saito and now I'm thinking I should have left it for another buyer. The needle valve assy (also has the fuel inlet) is broke and not complete, Horizon Hobby does not have that part as the newer carbs are different. Would anyone know where I could come up with one? I know I could buy a newer carb, but I don't really want to spend the money for this old engine. I thought about as a last resort, drilling and tapping the carb for a fuel nipple and using a remote needle valve. Also is the wrist pin full floating or is it pressed into the piston?
Thanks for your help
Bob

JettPilot

My Feedback: (6)

Can you tell me about your regulator leaking, and how you fixed it ? What kind of regultor was it ?

JettPilot

sundancer007

Mr Robinson. Several guys in my club have switched over to ceramic bearings. All 3 people have saito motors ranging from 82 to 125. Why do all of these motors leak oil in the front bearing after installing them? We all use heat,and not tapping the bearing. Is there a difference in bearing shields??? Stock NTN bearing shields are orange and smaller in diameter. The black shields are wider. Are the bearing shields on your engines (four strokes) black???? Im just trying to figure out why this is happeneing. I will not use the name of the manufacturer of ceramic bearings im speaking of. This is becoming more than coincidental.

sundancer007

As far as assembly method goes. Some of us the oven to heat the case to 350 deg. I use a jewlers torch to heat the case, slide the rear bearing onto the crank, re apply heat to the case inverted and the weight of the crank slides the bearing to the case with ease. I remove the crank and install the front bearing on the front half of the crank and position the outer race to the front case inverted. With heat, the bearing slides in smoothly and after cooling at room temp I remove the crank and install it in the case to finish assembly. The crank is seated with both bearings without gaps. Are we doing something wrong?? Do you have a prefered method? Im not trying to wear you out on this issue. And as always, I thank you for your knowlage.

rajul

My Feedback: (58)

Are the bearings specifications correct? Where did you get them from?

sundancer007

If I disclose that information it would not be fair to his or her buisness. The bearings I use are of high quality within spec.

sundancer007

Off site discussion. [email protected], We can discuss it here.

alfredbmor

I have a Saito .72 that I bought used on e-bay from a very liar dealer who is still selling engines from state sales, speaking for my experience, my engine did not start, I have some other Saitos and I know that they start easily, but this one wont. I had to change the bearings, ring and the carburetor; I had to invest a lot of money and time to make it alive and now run great, I had to break in again because I changed the ring. About the bearings I ordered the originals at the LHS, because I did not have enough information about others bearings, they are working great by now, about the way to change the bearings, I did it by the tough way. I did not know that I had to heat the case; I just made a home puller and pulled the bearings away and for the installation I did the same but I manage the puller from the center of the case. Now I realize that heating the case would be easier but no regrets I did it fine and the proof is still running ok. What I really want to post is to know how the heat affects the bearings seals, The front bearing has a kind of rubber seal that could be affected by heat, when you try to install the new bearing, you need to pull in to the case and maybe reheating with a torch as someone said or in the oven ruining the rubber seal. Well, the question would be, How to perform this task with out ruining the rubber seal in the front bearing?
Thanks.

sundancer007

Very good point!