Author Topic: OF FS40 cylinder removal - how? (Read 2447 times)

Dennis Toth · « **on:** April 28, 2014, 07:45:19 AM »

I have a OS FS40 that the shaft bearing was getting a little sloppy so I decided I would get new better quality bearing from Boca Bearing and replace them. I've been doing stuff to 2 strokes for 40 + years but as I got the head, push rods, cam out I discovered I have no way of prompting the cylinder up for removal.

So here I am - can anyone tell me how you get the cylinder/piston out of the OS FS40?

Best, DennisT

Bob Reeves · « **Reply #1 on:** April 28, 2014, 09:05:07 AM »

Sorry, wished I could help but never disassembled an OS. Have you tried Google, maybe someone else has had the same question.

Jim Kraft · « **Reply #2 on:** April 28, 2014, 11:03:38 AM »

Dennis, On my old ones with the rear cam the sleeves just slide out the top after you get the head off. Since there are no ports to use for pushing it up with the piston like on a 2 stroke, you might have to use a little heat. But, I have never had any problem by just sticking my thumb in the cyl. and pulling the sleeve out. If yours has a back plate you might also remove it and push the sleeve out from the bottom. Hope this helps.

Robert Zambelli · « **Reply #3 on:** May 07, 2014, 04:22:57 PM »

Remove the carb and intake pipe.
Remove the rocker cover and the rocker shaft.
Remove the remaining four bolts holding the head on.
Head should come right off.

Bob Z.

Dane Martin · « **Reply #4 on:** July 14, 2014, 06:30:06 PM »

ok. i got some pics. cylinder and piston removal.
pull the carb and intake assembly. pull the head and push rods.
pull the back plate. push up on the cylinder from the bottom to help pop it up.
line up the wrist pin with the wrist pin hole. remove pin and pull pisyon from the top and rod from the back.

Dane Martin · « **Reply #5 on:** July 14, 2014, 06:50:03 PM »

as you can see, this poor engine is in bad shape. the wrist pin is locked up. i just bake the engine at 300 for ten minutes. use a #1 extractor and it should pull out by hand. if not, bake the engine until the old nitro and gunk start to sweat on the wrist pin hole of the piston. this engine was really locked up and this method worked no problem. you can't get the piston out without pulling the pin. sorry four the bad pics. the engine was a little warm to work with and hold a camera!

Author Topic: OF FS40 cylinder removal - how? (Read 2447 times)

Dennis Toth

OF FS40 cylinder removal - how?

Bob Reeves

Re: OF FS40 cylinder removal - how?

Jim Kraft

Re: OF FS40 cylinder removal - how?

Robert Zambelli

Re: OF FS40 cylinder removal - how?

Dane Martin

Re: OF FS40 cylinder removal - how?

Dane Martin

Re: OF FS40 cylinder removal - how?