bigR

My Feedback: (2)

Hi,

I'm trying to take apart an FS 26 that was sitting for a few years after a crash of my seaplane. Since the model was in many pieces I wasn't able to run the engine after the dunking, as is usual practice after a trip underwater. I just thew the parts in the back of the shed and forgot about them. The liner is pitted and needs replacing, the rest of the steel parts are rusted. I have another crashed 20 FS with a bent crank. I think that I can mix and match to get one good engine, if I can get the 26 apart.

How do you take the wrist pin out? I see there is a hole in the back of the crankcase that lines up with the pin at a certain point of the crank rotation. But how do you push the pin OUT? I was able to remove the liner but can't get the rod off the crank as I'm able to do with other OS 2 stroke engines. I think the wrist pin needs to be pushed out of the piston to relaesa the rod.

Thanks,

John in Kalifornia

Bax

My Feedback: (11)

The wrist pin gets pulled through the hole in the case. We use a screw extractor to grip the inside of the wrist pin and remove it. If that doesn't work, you may just have to use a cutting tool and cut the connecting rod. Then you can put the piston on a wood block over a hole and drive out the wrist pin. Sometimes heating it will work.

Corrosion and old fuel residue can effectively 'glue' the wrist pin into the piston.

bigR

My Feedback: (2)

Thanks for the help. I guess that by screw extractor you mean an Easy-out. Maybe a sheet metal screw would work, but is probably not hard enough. The cutting of the connecting rod is the obvious solution, if a bit brute force.

BTW, if I need a new piston, ring and liner anyway, wouldn't it be possible to buy the parts for a 30 instead of the 26? I see that the head gasket, head and con rod are the same part numbers so I would assume the bigger liner and piston would fit. There is only a 1mm difference in the bore, stroke is the same. I know OS has in the past used the same O.D. liners for various sized engines. For instance, the old baffle piston 30 and 35s were the same except for the bore, with the 30 having a smaller piston and thicker liner.

John in Kalifornia

Bax

My Feedback: (11)

We don't know if the parts for the FS-30 will fit the FS-26. We always use the parts specified for the engine, and don't interchange between them.

Patxipt

OS FS-26 and OS FS-30 share all the components except the liner, piston, piston ring and gudgeon pin.
You can make a .30 engine and still be able to say "Oh, but mine is just a little .26..!"
You can do the same for the car version, it's a simple mod that gives more torque and a broader power band. Or turn a FS-26 into a FS-26C by changing the cam and valve springs.
Cheers!