SJN

Hi Guys.

I just bought a "used" saito 125, and it was crashed on its first flight. It had only run about 10 minutes.
I thought that I had got a great deal as the engine is spotless, and brand new.

But I just noticed that the crankshaft is bent

Im visiting a friend tomorrow, and see if we can streighten up the crank, but if that fails, Ill have to get a new one.

Looking at the horizon site, I can see some leters behind the description
" AG " "AH" What does this mean ?
http://www.horizonhobby.com/products/SAI125A23

I also found on on ebay where it is called "AB" " AC"
http://www.ebay.com/itm/Brand-New-Sa...item43ba38af1c


Whats the difference ?

Rudolph Hart

I don't know but $63.00 bucks is cheap for a crankshaft.The last one i bought was for an 82 i crashed,cost me $94.00 at the time.Don't forget to do the bearings as well.

blw

My Feedback: (3)

Horizon uses the letter alpha codes to indicate which engines a part will fit. Many parts are interchangeable. The 125 crankshaft codes are for the aluminum and Golden Knight engines. The Ebay codes you found are for the 82.

Here is the list: http://www.horizonhobby.com/article/...th-alpha-codes

SJN

ahhh...thanks, my bad :-)
I googled the ebay one, and did not notice that the partnumber was different.....doh....

blw

My Feedback: (3)

Well, you, me, and everybody else the first time we messed with a Saito. I always thought Horizon does a poor job explaining things.

bob62

My Feedback: (28)

Advantage Hobbies.com $57.81

SJN

Thanks.

I got my cranck straightened up using a lathe to hold and spin it around in, a micrometer guage, and steel rod inserted into the rear end of the cranck to bend it back into shape........fairly simple, and it is staight as an aroow now :-)

I wonder how it will hold up over time. I bet a bad prop strike, or small crash could easily bend it out of shape again...

bob62

My Feedback: (28)

If you bent it cold it most likely won't hurt it

blw

My Feedback: (3)

It may out live all of us. Glad you got it banged out straight again.

SJN

Got it all put back together and installed in a 60 size cessna and fired it up.....
Hmmmm..... it would idle realy high, even with the throttle barrel completly closed.

Took the engine out again, and foud out that the washer on the intake pipe that pushes against the o-ring into the cylinder head was missing.
Im quite sure it was missing all along.....as I cant find it on the floor here anywhere where i disassembled the engine.....

Anyway, I found an oversize washer in my spare box of bits, and used my Dremel to work it down in size for a perfect fit.



Starts and runs fantastic

Now off to the field and break it in once the weather gets better

http://www.youtube.com/watch?v=k6IevgNfvVI&feature=youtu.be

Cobra1

My Feedback: (42)

That washer needs to be made from aluminum as it needs to crush a little to create a seal. Copper would also work. A steel washer will leak. I have used a little high temp silicone in a pinch with good luck.

SJN

Hi Cobra

Are you thinking of a washer in the exhaust ?

The one I made is for the intake, and it only compresses the o-ring slightly to make a good seal. There is not enough pressure to even deform a copper or alu washer .

Cobra1

My Feedback: (42)

I understand. Thanks. Good luck.

Cobra1

My Feedback: (42)

Just looked at my 125a and I see what you are saying. Got confused with different size saito. Hope you get it sealed. A great running engine.

blw

My Feedback: (3)

You are getting into an area that caused Saito 72 owners a lot of headaches. This is a point where a little flexing of the intake manifold pipe will cause that little washer to bounce a little and suck in air. This causes the engine to go lean off and on. The 72's plastic backplate flexing was the culprit for the problem. Anyway, if the engine runs anything but 100% reliable I would put a coating of RTV under that metal washer until you can order a new one. The RTV should seal it fine if you need to go that route. You may never have any problems either, so good luck.

blw

My Feedback: (3)

I forgot to mention that I like your video of the 125 running indoors!

SJN

hehe, thanks for the tip.
Always test the setup before leaving home.........just to be sure :-)


Love my saito 72 too...never had a problem with it, and runs like clockwork :-)
http://www.youtube.com/watch?v=wHVHlfERjQg