Tearing down an old 266xp, I believe it is a 1988 model from the serial number. This is the first saw I have ever totally torn down and rebuilt.
A few questions:
Saw is old and had some use, but not much abuse it seems. Piston lower skirt on the intake side shows a bit of wear, as does the cylinder along that side. It isn't noticable marred or scratched, it is just that the original machining marks are gone and the cylinder and piston look smooth and shiny there. I am considering a new piston and ring...good idea?
Also, I have a spare Mahle cylinder I bought with the saw. The spare looks almost brand new, less wear than the other one. I bought the extra cylinder because I wanted to tinker with porting while in there and didn't want to mess up the OEM cylinder. The cyclinder looks identical to the one I took off, so I guess OEM was Mahle? I want to port the saw, but very mild stuff since this is my first effort a rebuilding a saw. I wonder the most bang for the buck there.
I know 266xps had different rings along their production, some the thin ring and some a thicker ring? Could I put a thicker ring and piston in this saw? Is there a benefit to the thicker ring? Also, if I buy a ring, will it be automatically the right size or will I have to check end gap at the end of the rings while the ring is in the cylinder? How much gap should there be cold? If I get it too tight, will it swell when hot and damage the saw?
I am familiar with how piston connecting rods work in cars. Typically they bolt it. However, it looks like the connecting rod is made in one piece as is an assembly along with the crankshaft? Are all saws made this way? Why?
How do I check the bearing between the connecting rod and the crankshaft? It seems to have a bit of play? How much is too much play? How do I know if I need a new crank?
Sorry if these are silly or if there are already answers on the forum. I'll continue using the search feature to try to find out.
Also, why are pistons oriented a certain direction? My piston has an arrow on it which was set up in the saw pointing toward the exhaust. The piston looks symmetrical, so why would it matter if the ring opening were toward intake or exhaust side? Would exhaust pressure open up the ring if it were put in backward?
A few questions:
Saw is old and had some use, but not much abuse it seems. Piston lower skirt on the intake side shows a bit of wear, as does the cylinder along that side. It isn't noticable marred or scratched, it is just that the original machining marks are gone and the cylinder and piston look smooth and shiny there. I am considering a new piston and ring...good idea?
Also, I have a spare Mahle cylinder I bought with the saw. The spare looks almost brand new, less wear than the other one. I bought the extra cylinder because I wanted to tinker with porting while in there and didn't want to mess up the OEM cylinder. The cyclinder looks identical to the one I took off, so I guess OEM was Mahle? I want to port the saw, but very mild stuff since this is my first effort a rebuilding a saw. I wonder the most bang for the buck there.
I know 266xps had different rings along their production, some the thin ring and some a thicker ring? Could I put a thicker ring and piston in this saw? Is there a benefit to the thicker ring? Also, if I buy a ring, will it be automatically the right size or will I have to check end gap at the end of the rings while the ring is in the cylinder? How much gap should there be cold? If I get it too tight, will it swell when hot and damage the saw?
I am familiar with how piston connecting rods work in cars. Typically they bolt it. However, it looks like the connecting rod is made in one piece as is an assembly along with the crankshaft? Are all saws made this way? Why?
How do I check the bearing between the connecting rod and the crankshaft? It seems to have a bit of play? How much is too much play? How do I know if I need a new crank?
Sorry if these are silly or if there are already answers on the forum. I'll continue using the search feature to try to find out.
Also, why are pistons oriented a certain direction? My piston has an arrow on it which was set up in the saw pointing toward the exhaust. The piston looks symmetrical, so why would it matter if the ring opening were toward intake or exhaust side? Would exhaust pressure open up the ring if it were put in backward?
