O.S. 21MX VII parts

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Bill Gibson

Well-Known Member
Supporting Member
Joined
Mar 7, 2007
Messages
3,739
I just acquired one that doesn't appear to have had more than a few ounces of fuel run thru it, but unfortunately the previous owner didn't bother to flush and oil it, so......

The rear main bearing is bad....the front still looks like new and is very smooth

The piston doesnt rock freely on the wrist pin....got it apart, and the wrist pin is shot.

Piston and sleeve look fine, no sign of siezure.

So I'm in need of:

A new wrist pin, and a coupla sets of circlips.

Possibly a new rod.

So I was wondering if someone could point me in the right direction as to where to buy parts?

I've never owned an O.S. outboard, all I ever ran was K&Bs!

Haven't messed with nitro motors in a while and I can't remember what to use to clean up/ polish parts like the piston, crank, etc.

Many Thanks!!
 
Look in the manufacture or parts post as there is somebody other than Tower handling OS parts or E-bay if all else fails. Cleaning and polish you could use WD but someone else may have a better way. Looked in Manufacture s and Ron Shaw has parts.

Brad
 
Last edited by a moderator:
I just acquired one that doesn't appear to have had more than a few ounces of fuel run thru it, but unfortunately the previous owner didn't bother to flush and oil it, so......

The rear main bearing is bad....the front still looks like new and is very smooth

The piston doesnt rock freely on the wrist pin....got it apart, and the wrist pin is shot.

Piston and sleeve look fine, no sign of siezure.

So I'm in need of:

A new wrist pin, and a coupla sets of circlips.

Possibly a new rod.

So I was wondering if someone could point me in the right direction as to where to buy parts?

I've never owned an O.S. outboard, all I ever ran was K&Bs!

Haven't messed with nitro motors in a while and I can't remember what to use to clean up/ polish parts like the piston, crank, etc.

Many Thanks!!
Hey Willie,

Get ahold of Ron Shaw,, he will have everything you need
 
I have all those parts in stock, you would need to allow 8-10 business days to arrive from Australia.
 
I just acquired one that doesn't appear to have had more than a few ounces of fuel run thru it, but unfortunately the previous owner didn't bother to flush and oil it, so......

The rear main bearing is bad....the front still looks like new and is very smooth

The piston doesnt rock freely on the wrist pin....got it apart, and the wrist pin is shot.

Piston and sleeve look fine, no sign of siezure.

So I'm in need of:

A new wrist pin, and a coupla sets of circlips.

Possibly a new rod.

So I was wondering if someone could point me in the right direction as to where to buy parts?

I've never owned an O.S. outboard, all I ever ran was K&Bs!

Haven't messed with nitro motors in a while and I can't remember what to use to clean up/ polish parts like the piston, crank, etc.

Many Thanks!!
Hey Willie,

Get ahold of Ron Shaw,, he will have everything you need
Thank you Rick!!

Willie,

I am now carrying the OS Outboards complete, lower units complete, as well as all of the parts in stock at prices below Tower Hobbies to keep parts and engines available for the boaters that run the IMPBA Sport 21 and NAMBA 21 OPC classes. Here is the link. Thanks.

https://www.novarossi.us/collections/os-stock-outboard-engines-and-parts
 
Bill, as for cleaning a motor for bearing change/repair I take everything apart and remove any o/rings then soak overnight in mineral spirits. Then use a stiff toothbrush to scrub everything well, especially the case and any carbon on face of piston. I use a hair dryer to dry off residual mineral spirits. After heating and removing the old crank bearings I clean the bearing journals of case with cotton swabs soaked in Brake Kleen (the original not the newer green crap). If top of piston still has residual crud I use Brake Kleen there also. I strongly caution using ANY fine grit wet-dry, if its that bad I would replace the parts anyway as theyre already compromised from corrision. Just my $.02 I learned from the MASTER Rod Geraghty years ago
default_smile.png


Wallster
 
Addendum. If the head and backplate bolts are questionable buy a new set from Ron also. For assembly, lube the new bearings and rod bushings with caster oil, lube all other internal parts with air tool oil or similar, lube all bolt threads with Corrosion X, torque bolts on the OS .21 to 8 inch pounds. With the OS nickel liner be sure to always run a bit on the rich side. Best of luck with this, these can be really awesome little motors if treated well!

Wallster
 
I just acquired one that doesn't appear to have had more than a few ounces of fuel run thru it, but unfortunately the previous owner didn't bother to flush and oil it, so......

The rear main bearing is bad....the front still looks like new and is very smooth

The piston doesnt rock freely on the wrist pin....got it apart, and the wrist pin is shot.

Piston and sleeve look fine, no sign of siezure.

So I'm in need of:

A new wrist pin, and a coupla sets of circlips.

Possibly a new rod.

So I was wondering if someone could point me in the right direction as to where to buy parts?

I've never owned an O.S. outboard, all I ever ran was K&Bs!

Haven't messed with nitro motors in a while and I can't remember what to use to clean up/ polish parts like the piston, crank, etc.

Many Thanks!!
Hey Willie,

Get ahold of Ron Shaw,, he will have everything you need
Thank you Rick!!

Willie,

I am now carrying the OS Outboards complete, lower units complete, as well as all of the parts in stock at prices below Tower Hobbies to keep parts and engines available for the boaters that run the IMPBA Sport 21 and NAMBA 21 OPC classes. Here is the link. Thanks.

https://www.novarossi.us/collections/os-stock-outboard-engines-and-parts
Ron, you have a PM!!
 
Back
Top