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-   -   Broken pushrod on lightly used Saito 100 (http://www.rcuniverse.com/forum/glow-engines-114/11333970-broken-pushrod-lightly-used-saito-100-a.html)

skrez 12-16-2012 05:53 PM

Broken pushrod on lightly used Saito 100
 
Hi Guys,
I purchased a brand new Saito 100 in 2007 , broke it in according to the manual and flown it less that 12 times. I also set the valve clearance to .002-.003 after break-in . I pulled the vavle cover off today to do my winter maintance and found the broken pushrod. What would cause this, is this common on 4-strokes? Guess I will have to send it to horizon for repair. :(
thanks,
Frank

Hobbsy 12-16-2012 05:58 PM

RE: Broken pushrod on lightly used Saito 100
 
A pushrod should be easy to order and install.

Ernie Misner 12-16-2012 06:02 PM

RE: Broken pushrod on lightly used Saito 100
 
Hobbsy, can you just pull the valve cover and drop the pushrod right down in. That easy?

Hobbsy 12-16-2012 06:13 PM

RE: Broken pushrod on lightly used Saito 100
 
I think that if you press the valve spring down the short end of the rocker will move up and away just enough. I'll try it on an .80 tomorrow.

jeffie8696 12-16-2012 06:31 PM

RE: Broken pushrod on lightly used Saito 100
 
Iwould like to know what tach readings you are getting. I suspect it may be overrevving if its underpropped. It causes a lot of strain on the valvetrain.

skrez 12-16-2012 06:38 PM

RE: Broken pushrod on lightly used Saito 100
 
I was using a 14X8 apc taching at around 9000 rpm
Frank

blw 12-16-2012 06:47 PM

RE: Broken pushrod on lightly used Saito 100
 
That isn't close to over reving on the ground. Saito says 11,000 rpm, so figure around 10,000 on the ground. It's a judgement call since we don't know how much it unloads in the air. I use about a thousand rpm for headroom.

I'm curious to see if Dave can slip one in on his 80.

jeffie8696 12-16-2012 07:13 PM

RE: Broken pushrod on lightly used Saito 100
 
Ditto

w8ye 12-16-2012 08:14 PM

RE: Broken pushrod on lightly used Saito 100
 
Well, You can slip the pushrod out of the socket by pushing down on the spring but the pushrod will not come up past the side of the rocker arm to get it out or the new one in.

I just remove the carb and back plate, then lift the cylinder/piston/rod off. Then install the new puchrod in the tube and stick it all back together.

Ernie Misner 12-16-2012 08:21 PM

RE: Broken pushrod on lightly used Saito 100
 
I think I saw specs on an OS buggy 4-stroke engine that turned 20,000 rpms a few years back. Don't think I was dreaming. How did they do that?

jeffie8696 12-16-2012 09:24 PM

RE: Broken pushrod on lightly used Saito 100
 
Cant you just remove the rocker shaft and take off the rocker arm?

proptop 12-16-2012 10:19 PM

RE: Broken pushrod on lightly used Saito 100
 

Quote:

ORIGINAL: jeffie8696

Cant you just remove the rocker shaft and take off the rocker arm?





Yeah....it's a lot easier to do it that way...

w8ye 12-17-2012 12:18 AM

RE: Broken pushrod on lightly used Saito 100
 
Many times the rocker shaft pivot screws don't want to come out.

Giant_Scale_Gasser 12-17-2012 03:48 AM

RE: Broken pushrod on lightly used Saito 100
 
Just remove the rocker pivot shaft and replace the pushrod. Literally 5 minutes. and the pushrods are super low cost.

Old Fart 12-17-2012 04:18 AM

RE: Broken pushrod on lightly used Saito 100
 
I'm with w8ye in that it takes a real good flatblade screwdriver,a bit of muscle and a lot of luck to unlock the rocker pivot arm screw

the pope 12-17-2012 04:50 AM

RE: Broken pushrod on lightly used Saito 100
 

Quote:

ORIGINAL: Old Fart

I'm with w8ye in that it takes a real good flatblade screwdriver,a bit of muscle and a lot of luck to unlock the rocker pivot arm screw
That makes 3 . Much easier to lift the barrel , I have found . Cheers the pope

Hobbsy 12-17-2012 05:43 AM

RE: Broken pushrod on lightly used Saito 100
 
1 Attachment(s)
There is a way, this is a .65, so if the 1.00 pushrod is not too fat.

http://www.horizonhobby.com/products...-qq-SAIE100#t4

w8ye 12-17-2012 06:02 AM

RE: Broken pushrod on lightly used Saito 100
 
The rocker arm and pushrod are the same on the 100 and the 65

Hobbsy 12-17-2012 06:04 AM

RE: Broken pushrod on lightly used Saito 100
 
Jim, I tried to find the Alpha Numeric chart at Horizon.com but like the rest of their site, I couldn't find it.

blw 12-17-2012 07:11 AM

RE: Broken pushrod on lightly used Saito 100
 
http://www.horizonhobby.com/article/...th-alpha-codes

VictoryRoll 12-17-2012 10:24 AM

RE: Broken pushrod on lightly used Saito 100
 
If you do-it-yourself, does that kill the warranty? I know Frank's is already out of warranty, but I am just curious.

Hobbsy 12-17-2012 10:50 AM

RE: Broken pushrod on lightly used Saito 100
 
I think its going to turn out that a valve was stuck open. Horizon is beyond fair with warranty issues but I can't answer that directly.

Hobbsy 12-17-2012 10:51 AM

RE: Broken pushrod on lightly used Saito 100
 
Thanks Barry, I added that to me Favorites

skrez 12-17-2012 11:02 AM

RE: Broken pushrod on lightly used Saito 100
 
Well guys, thank you for all your help. I have been away from glow planes for a few years and flying electric planes and EDF`s. so I forgot allot. As it turns out , it seems that the rod was just stuck in the down position and after I put some air tool oil in the valve areas now it looks fine. I reset the valve clearance to .003 and everthing seems to be normal with the movment on the valves and rods. But I wondering if I should pull the rod out anyway to see if it is bent? I`m not sure why it would have stuck in the down position in the 1st place?
Frank

Hobbsy 12-17-2012 11:05 AM

RE: Broken pushrod on lightly used Saito 100
 
More than likely the valve was stuck and not the pushrod.


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