[dhaniellemar63]

Thanks for the info. I usually use ME to get the info i need for parts, but they do not have the FD-10 listed. I got my hands on the attached parts list, and it indicated 301787 for the piston rings. Wasn’t able to bring up the part number, so that led to my confusion. I will try get some more info from the ebay link that Mumbles posted. I am not in a hurry as this motor has been in various states of repair for over a year. I had the pistons soaking in a carb kit for months with the hope the rings would come loose and could be salvaged. Finally gave up and ended up busting them out. [links]

[nacarino]

These might be the ones you want. It sure looks like 378416 written on the box and they are about half the price of the ones from ME including shipping from the other side of the planet. A cross reference to the Perfect Circle P/N would sure be handy right now.

http://www.ebay.com/itm/Piston-Ring-Set … 2017262958

[jesmurf]

word of caution…. shipping from the other side of the planet….takes time

[jumolock1976]

All it takes is money. marineengine.com has them. Part number 378416 for a set of three rings.

[oUmber]

OK, good to know…The FD 15hp models shared the same rings bore size as the QD 10 hp series, got it now… [links]

[HopeFlynn7x]

My OMC Superceding Parts List shows the original 301787 ring set superceding to 486278 which is the number on the Perfect Circle packaging used by OMC and then superceding again to the current 378416.

[Galuel]

RPM Information: 5000
Your engine's RPM range is important in choosing the right propeller for a given application. For example, if you look at your tachometer at top speed and it is not within the engine's RPM range then that is generally not good. You want your RPM's to be within the proper range while at wide open throttle (WOT). Be sure to do your testing under your normal boating conditions and with a good propeller (not bent, cracked, or excessively chipped).

[bart27newton]

The iboats Outboard Motor Forums are another excellent source of information.

[tsxparts01]

more

[fabianhjr]

This tool is to set the air gap between the coil heels and the flywheel magnets, it works for motors from 3-40hp 1951-1976 and many beyond that.

[gekko]

This locates the coil heels with the correct gap to achieve the best spark, Simply locate ring on the "bosses" machined into the armature plate, pull coils towards to the ring and tighten the coils down firmly. That is it.

[earney]

These are the OEM part number(s) for this tool, it can be under any of the three numbers, 0317001, 334994 or CDI 553-4994 more

[vfdsaq]

If the first method doesn’t work, try this: here

[mezz]

Here’s an example video of what it looks like when you decarb a boat motor. Lots of smoke!
here

[kaja]

Here are two affordable and timely ways you can decarb your boat motor: here

[buck]

It might be time to decarb your boat motor if you start it and find that white smoke starts to billow out of it. Decarbing is short for “decarbonization,” a term that refers to decreasing the amount of carbon in metal. During the course of time, carbon tends to build up along the exhaust chamber walls of a boat motor. This causes problems such as odors, smoke, and rough engine or idle performance. But that doesn’t mean that you dock your boat and wish you had another one.

[osjak]

Decarbing is generally not necessary on 4-stroke motors as they don’t build up nearly as much carbon as 2-stroke motors do. However, if you spend a lot of time at idle or trolling and rarely push your motor to the upper RPM ranges, you may wish to occasionally decarb as a preventative measure.