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-   -   saito .91 rebuild help please (http://www.rcuniverse.com/forum/questions-answers-154/10848326-saito-91-rebuild-help-please.html)

SCOTT42 12-07-2011 12:43 PM

saito .91 rebuild help please
 
1 Attachment(s)
Ive just replaced the bearings in my saito .91, every thing has seemed to go good with the exception of two little plastic parts, and the thing is that I didnt see them when I was diasembling the engine and have no Idea where they came from or where they go back to. I have a large pickle jar that I put all the parts in and then soak them in acohol and im not sure if those were in the jar from another project or not. Can some one help me out here please? I have looked at a scematic and I really cant tell if they are part of the tappets or not.

rhutson172 12-07-2011 01:14 PM

RE: saito .91 rebuild help please
 
I don't think those belong on your engine...any plastic part would melt when the engine heated up.

MetallicaJunkie 12-07-2011 01:17 PM

RE: saito .91 rebuild help please
 
those retain the piston pin thing...lol i cant remember the name... they are Teflon, and belong there other wise you will kill your engine with out them

look on the exploded diagram they are clearly visible

http://www.horizonhobby.com/pdf/SAIT...der_Manual.pdf

SCOTT42 12-07-2011 01:24 PM

RE: saito .91 rebuild help please
 
Yor talking about the wristpin, I just went to see if they fit and they do, now it makes sents to me and thats why I didnt see them when takeing it apart. Before I try to put it back together I want someone else to chime in about it just so I know for sure thats where they go. Thanks.

MetallicaJunkie 12-07-2011 01:27 PM

RE: saito .91 rebuild help please
 
yes 100% they belong in there..... ive rebuilt several saitos

SCOTT42 12-07-2011 01:29 PM

RE: saito .91 rebuild help please
 
I agree, I just took another look at the schematic and boom there they are! Thank you. Lesson learned today! thanks

SCOTT42 12-07-2011 01:45 PM

RE: saito .91 rebuild help please
 
Allso while im at it, how do I tell if Ive got the timeing set right or not as I cant find a mark on the crankcase, do I just set the piston to TDC? I see the mark on the cam gear< so my thinking isTDC with the cam mark down and thats the timeing set?? pleas if theres another way I need to know soon thanks.

MetallicaJunkie 12-07-2011 03:16 PM

RE: saito .91 rebuild help please
 
Quote:

piston TDC then there is a mark on the cam gear , itAllso while im at it, how do I tell if Ive got the timeing set right or not as I cant find a mark on the crankcase, do I just set the piston to TDC? I see the mark on the cam gear< so my thinking isTDC with the cam mark down and thats the timeing set?? pleas if theres another way I need to know soon thanks.
yes thats correct.... i usually heat up some vaseline in a bowl in microwave and pour it into the cam gear housing and align it so that the little dot will point down when it comes time to install it


after i set it ,,, i put it in the freezer for a few mins so that way it wont move accidentally while im installing it

Gray Beard 12-07-2011 03:44 PM

RE: saito .91 rebuild help please
 
The first time I saw those critters was when I was building VW engines for sand buggies. They were just called Teflon wrist pin buttons or just Teflon Buttons. We replaced the wrist pin snap rings with them. Snap rings on high horse powered engines often broke so they came up with the buttons. Because I rebuild a lot of older four stroke engines I run into both buttons and snap rings. I like the buttons better myself but it's just a choice thing. I have never had a snap ring come loose in a glow engine, I did have one come loose in a V-8 Ford but that engine has 240K on it. It was just it's time to have something come loose.

SeamusG 12-07-2011 05:13 PM

RE: saito .91 rebuild help please
 
Saito 91 rebuild thread

HTH

tacx 12-07-2011 06:27 PM

RE: saito .91 rebuild help please
 
Set your engine up so that its secured upright on a table or bench that you can get down and eyeball it from the front. Set the piston to TDC. While holding the cam gear housing, position the dot on the gear at 6 O'Clock. Now, take a single edge razor blade or some other very thin flat thing and hold it up against the bottom of the gear housing and slide it into the gear teeth to hold the gear in place. Make sure the dot is still at 6 o"clock. Holding the gear at that position lower the housing onto the crankcase. Once you have the gear housing down on the crankcase, slide out the thin tool and install your bolts.

Edwin 12-07-2011 06:44 PM

RE: saito .91 rebuild help please
 
Another to reinforce whats been said. Put them in.
Edwin

SCOTT42 12-07-2011 07:56 PM

RE: saito .91 rebuild help please
 
Thank you seamusg, I did get it all put back together nicelly, I made a makeshift motor mount on my work bench and fired it up. It ran, but it was slugish and backfired once, so that tells me its off. Only if I had read that post before I put it all back together? Hey Im learning here! So tomorrow I get to tear it apart again and redo it, no big deal. Thanks for the info.Wish me luck.


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