Question about reassembling my Saito 45 engine
 

I plan to dis-assemble my Saito 45 shortly to give the bearings a good clean. I have pulled apart & re-assembled many 2 stroke engines with plain & ball bearings but none with a ringed piston. I am not concerned about re-setting the timing as I intend to study carefully, take some pics with the digital camera before I start & then work steadily. My concern (imagined or real) is sliding the piston & ring back into the barrel. What's the best way/technique to keep the ring compressed so the piston will slide easily back into the barrel?

RE: Question about reassembling my Saito 45 engine
 

Bone:

No problem at all. There is a cone section at the bottom of the bore to compress the ring. Just be careful not to tip the piston as it goes in.

Bill.

RE: Question about reassembling my Saito 45 engine
 

Slow and easy is the method.

Unless you are going to replace the ring, it is not necessary to remove the piston/ring from the cylinder? If you do not disturb the ring's "seat" in the cylinder, you will not have to go through the process of re-seating the ring.

Enjoy,

Jim

RE: Question about reassembling my Saito 45 engine
 

[b]Bone:

Jim is right. If you're only changing bearings, then after the back plate is off lift the cylinder about 1/4" and just slide the con rod off the crank, leaving the piston in the cylinder.

I went right to reinstalling the piston, ignoring the statement about tbe bearings.

Bill.

PS: Best source is RC-Bearings, http://www.rc-bearings.com/ . wr

RE: Question about reassembling my Saito 45 engine
 

Thanks Jim & Bill :) You both make very good points. Again, thank you for the information

RE: Question about reassembling my Saito 45 engine
 

Bone: Here is what a Saito .45 looks like in pieces.

RE: Question about reassembling my Saito 45 engine
 

Kmot - thanks for the pic of all the bits. Makes interesting viewing. The discolouration on the cam main gear & crankshaft - is that castor residue or something else ?

RE: Question about reassembling my Saito 45 engine
 

Bone:

That's the color they come from the factory. Here's a new cam shaft, and two shots showing why you should not run all synthetic oil.

I stuck my nose in because I probably have more failure pictures from Saito engines than anyone else.

Bill.

RE: Question about reassembling my Saito 45 engine
 

Hi Bone,

That discoloration you see is a combination of dried castor oil and my home brew after run oil. You can also see some on the backside of the drive washer and on the side of the con rod.This engine sat in a baggie after I oiled it, for 14 years or so.

Bill, clean the spit off your screen! Haw! :D

RE: Question about reassembling my Saito 45 engine
 

Tom:

Spit? As Molly said. "'Taint funny, McGee." That third picture is a combination of lubrication failure, hammering from loose valve adjustment, and electrolysis from leaving the acids in the bottom end, acids that would be neutralized with any good after run oil. Including plain old ordinary ATF.

Bill.

RE: Question about reassembling my Saito 45 engine
 

Hello; Seeing that exploded picture reminded me how difficult it can be to get the teflon washers on the cam Idler shaft. Whatever you do, don't leave those washers out, or the cam shaft will ream a brand new hole in your case.

Bill, you got that picture of my cam shaft pretty sharp, sharper then the original. Don't forget to mention that it was in my sea plane, so some of that corrosion might have been sea water.

RE: Question about reassembling my Saito 45 engine
 

DD:

Forgot that was your cam.

But seawater? I brought an FA-72 back from a salt water death, there was no sign of elecgtrolysis. Here's a picture of the cam in its housing, and another of the bottom of the piston. The only parts needed were a new ring and a set of bearings. Gaskets, of course.

Bill.