Is my OS 21 Outboard worn out?

Hi all

I've got an OS 21 Outboard v1 engine which was bought for me when I was about 11 (I am 34 now) - and we've always looked after it well. It starts first time, is reliable etc.

However, I am beginning to wonder if its worn out and if I should replace it with a V2. I dont know a huge amount about engine maintenance or what could be causing its behaviour. Hoping I can share info here and get some feedback on how to proceed

What caused this as well, is my Dad has a new v2 (only 1 year old) with the same boat (Aeromarine Predator) so its a pretty good apples to apples comparison.

So in short, my engine doesn't throttle up and down very well. It seems to have 3 speeds, idle, fast idle, and full speed. Going up and down the throttle range gives no change in output/performance until you hit certain points with the throttle stick.

It isn't fast. Nothing like it used to be. Dads boat can literally do circles around mine.

So its a lack of power and poor throttle response. Engine still has compression although not as good as Dads one (granted given tthe age and usage difference between them)

What would you do? I've tried playing with the mixture a lot and never made much/any notable difference. I know parts are available so if say it needed a new piston and liner etc it could be done. If it sounds like it could be repaired I would be up for attemtping to do this (and also take the opportunity to learn more about engines)

Thank you in advance

I would replace the bearings and conrod, all o-rings in the carburetor. And if the piston can be pushed straight thru the liner. then replace piston/ liner as well.
There is no need to buy a new engine as they are practically the same. All parts from V2 will fit your V1.
Now if you can get an ok deal it may be close to break even between buying a new engine or buy new parts.
In that case you will have a spare lower that may sell for somewhere around 100 bucks if it is in good shape.

As the Joern said...but at the very least, do all 4 bearings (motor and PTO).

If you get a V2 muffler, then yours will almost be the same spec as your dads.

id check the Piston and sleeve. The sleeve has a tendency too wear out.