|
The PIPE -> RE: Welcome to Club SAITO ! (9/19/2005 2:49:37 AM)
|
I had JUST this sort of problem crop up on my Saito 56 while breaking IT in 2-1/2 years ago...
Dear LedSled:
The PIPE here again...I had this EXACT "bearing shriek" problem come up in the Spring of 2003 while breaking in my Saito 56 four stroker...and from my reply in a thread at http://www.rcuniverse.com/forum/m_670560/anchors_670560/mpage_1/anchor/tm.htm#670560 , here's my account of that occurrence and my solution to it...!
Any additions to the original text will be enclosed in [brackets] to clarify what I was saying..."here goes"...
"The Saito 56 I have, started running with a 12 x 6 Master Airscrew fiberglass prop, at the "fast idle" setting recommended by Saito, at around 3900-4000 rpm for about a GOOD 30-40 minutes. The fuel is FHS Red Max 10% nitro, 17% all synthetic oiled [four stroke] fuel, with the oil content "spiked" up slightly to about 20% for that first tankful.
After the fast idle initial run-in, I started running the 56 at full throttle, but at a BLUBBERING rich setting that made the engine emit SO much gray smoke that it looked a bit like I was "fogging for bugs" at my club's flying site.
I gradually leaned out the motor, but a mysterious SHRIEKING noise started to intermittently pierce my hearing...the it became more "continuous", so I stopped running the engine, removed each of the valve covers, and tried squirting a GOODLY "slug" of Marvel Air-tool Oil into each open valve cover and DOWN THE PUSHROD TUBES to really SATURATE the camshaft compartment and crankshaft bearings!
Re-starting the 56 seemed to bring back the "shriek". but I then stopped the 56, waited a short while, and tried spinning it over with my starter, with NO glow plug power or fuel feed to the motor...and it SEEMED that the shriek might be "over"...connecting everything back up, and restarting the engine yet AGAIN "this time" brought out that GREAT four stroke sound, with NO shrieking noise, so the Marvel Air-Tool oil seemed to have done its job-and the shrieking has NOT come back since."
Marvel Air-Tool Oil should be available in most any well-stocked auto parts store (particularly a REGIONAL chain store...it's NOT as likely to be in a national chain auto parts place) in 4-1/2 ounce bottles...and where our model engines ARE essentially "air pumps", if they were NOT burning FUEL in them, that Marvel Air-Tool Oil has emerged as a PREFECT solution to the bearing shriek problem...AND to "pickle" your four stroker in as an after run and long term storage oil.
Hope this tip helps make your Saito "mill" LESS prone to "getting scared" [IMG]http://instagiber.net/smiliesdotcom/otn/shocked/eek.gif[/IMG] and start SHRIEKING again...!
Yours Sincerely,
The PIPE! ;)
|
|
|
|
