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Engine basics => Four strokes only => Topic started by: Joe Yau on April 07, 2011, 12:31:14 PM

Title: Saito front bearing question..
Post by: Joe Yau on April 07, 2011, 12:31:14 PM

I have a Saito .56 CL engine that I removed from a stunter, cause I was getting some odd inconsistent runs. After I put the after-run oil in to stored it away with crankshaft down.  I notice on the next day.. almost all the oil has drained back out through the front bearing. Is that normal or the seal has gone bad?  I thought the front bearing was suppose to be sealed.

(http://img.photobucket.com/albums/v612/JOE91SC/IMG_0554.jpg)
(http://img.photobucket.com/albums/v612/JOE91SC/SaitoRebuildPartsandTool001b.jpg)

Title: Re: Saito front bearing question..
Post by: Bob Reeves on April 08, 2011, 05:16:00 AM

Personally, as long as the bearing feels OK I wouldn't worry about it. 4 strokes don't depend on crank case pressure like two strokes and it won't cause any run issues. I don't like taking engines apart unless it is a must do and in this case I don't see a problem. The oil could have leaked out the breather but in any case as long as the bearing is OK I would just run it..

Title: Re: Saito front bearing question..
Post by: Joe Yau on April 10, 2011, 10:42:27 AM

Quote from: Bob Reeves on April 08, 2011, 05:16:00 AM

Personally, as long as the bearing feels OK I wouldn't worry about it. 4 strokes don't depend on crank case pressure like two strokes and it won't cause any run issues. I don't like taking engines apart unless it is a must do and in this case I don't see a problem. The oil could have leaked out the breather but in any case as long as the bearing is OK I would just run it..

Thanks Bob.   H^^ The bearing seems fine, and the breather was plugged. I think the run issue is probably not enough prop loading with a 12" 3-blade..  and there's no ground clearance for 13" dia. HB~>

Title: Re: Saito front bearing question..
Post by: Bob Reeves on April 10, 2011, 11:22:30 AM

Bend longer landing gear.. That is what I did on my Score..

Title: Re: Saito front bearing question..
Post by: Douglas Ames on April 13, 2011, 03:24:23 AM

Quote from: Joe Yau on April 10, 2011, 10:42:27 AM

...and the breather was plugged. // ...I was getting some odd inconsistent runs.

Were you running it with a plugged breather? (...or did you just store it that way?)
That would explain your blow-bye and "odd runs" due to excessive C/C pressure.

Title: Re: Saito front bearing question..
Post by: Joe Yau on April 13, 2011, 12:57:18 PM

Quote from: Douglas Ames on April 13, 2011, 03:24:23 AM

Were you running it with a plugged breather? (...or did you just store it that way?)
That would explain your blow-bye and "odd runs" due to excessive C/C pressure.

I just stored it that way.. basically to see if the After-run oil was coming out from there, it obviously was not.  It also explains why the spinner had so much oil in it, and I notice that every time I take it to the field..  from storing the plane nose down.