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FDE 11 Piston me Off

Posted: Tue May 22, 2018 4:30 pm
by effenaco
My FDE 11 needs a new piston so I decided to replace the set. Original part number was 376992. It has been superseded by 385338. I ordered a set of these and when I got them they are 2 ring pistons, not three ring pistons which are currently in the motor. Does anyone know if this is a correct replacement and will there be any issues if it is OK to convert? OK experts, weigh in and let me know. Thanks

Re: FDE 11 Piston me Off

Posted: Tue May 22, 2018 5:11 pm
by retiredoz
Unless the picture is wrong ?
http://www.marineengine.com/newparts/pa ... OMC0385338

In any event, that's what my '75 Johnson parts book calls for for your FD-11.

Re: FDE 11 Piston me Off

Posted: Tue May 22, 2018 6:00 pm
by FrankR
They went to two-ring pistons a long time ago. No problem. Actually, pressure back rings came later on.

Re: FDE 11 Piston me Off

Posted: Tue May 22, 2018 6:00 pm
by FrankR
Deleted duplicate post

Re: FDE 11 Piston me Off

Posted: Wed May 23, 2018 8:00 am
by effenaco
I bought the replacements from Marinengine.com based on that picture, but what arrived were two ring pistons. Then I bought another on ebay and same thing, two rings.

Re: FDE 11 Piston me Off

Posted: Wed May 23, 2018 2:23 pm
by retiredoz
My '69 parts book lists this piston for your FD-11 (383476)


https://www.ebay.com/itm/CLEAN-1969-197 ... SwIGJaN-pY

Re: FDE 11 Piston me Off

Posted: Tue May 29, 2018 6:43 am
by effenaco
Yes looked at that one as well. Still two ring even though pictures everywhere show it as a three ring. Again my question is, will there be any problems or other modifications needed to swap the three ring pistons for two ring?

Re: FDE 11 Piston me Off

Posted: Tue May 29, 2018 7:14 pm
by Garry in Tampa
No problems at all. As long as the pistons are properly fitted, two ring pistons are thought to be fractional more efficient (Less drag) than three ring pistons. They are favored in racing motors. Also, adding rings does little to help a poorly fitted piston. . . 8-)
Image

Re: FDE 11 Piston me Off

Posted: Thu May 31, 2018 7:48 am
by effenaco
Garry,

Thanks. I just wanted confirmation from an expert. Hope all is well.

Barry