Bax,

I recently picked up an OS .46 FX NIB. Somebody at my club told me that the reason they quit building this engine is because the plating on the cylinder sleeve peels? I have many OS engines, 2 .61's and 2 .91's of which are FX series with lots of hours and zero problems. Is there something different about the .46 FX and is this something to be concerned about? Or is this typical rumor mill stuff?

Thank you in advance for your response and thank you for all the information you have provided in the past.

Mike P.

Some of the early .46 FX engines did have difficulties with liner plating. That's why O.S. developed the ABL type of cylinder liner, which eliminated the difficulty. That liner was incorporated in the FX-series of engines. The AX line was developed as a replacement for the FX line because it was time for a model change. They have different styling and different port timing for slightly-different handling and performance.

I have a 46 FX, how do I know if I have an early production engine, and can a liner be replaced with the later model liner?

You can only tell if the liner plating fails. No way to tell by visual inspection.

Bill,

I have one in which the liner failed and would be interested in the answer to the previous question. I interpret it to mean, If I replace the liner will I have the same problem again?

BTW I have a couple of the new .46AX's and think they're great!

The new ABL liners O.S. developed have had no difficulties related to the plating process.

Thanks Bill,

Here is a picture of the liner and I also have a question about the intake under the carb.

I'm new at taking engines apart and would also like to know the best way to get the crank and bearings out.

If you look at the picture of the intake, do you see the lines around the shaft? It looks like wear to me but I don't know if it's normal or not. This engine was run about 1 summer, maybe 3 gallons of Powermaster 15% through it, it was never wrecked. It got to the point it was more hassle to use than it was worth and I put it on the shelf.

Thanks for any help.

Bob Beatty

I finally got the crank out and the crank case is scored like the crankshaft (picture 2)

The scoring in the case indicates that the engine's ingested quite a bit of dirt. That's what causes the scoring of the case under the carb opening. That could also have started the cylinder liner's peeling.

Yeah, thanks.

Thanks for the tips on how to get the crank and bearings out too...

Once the head and rear cover have been removed, the liner can be pushed straight up, out of the case. If it's a bit 'reluctant', you can heat the case a bit. With the liner out, the rod and piston will come out. Make sure you mark them so they go back the same way. With the rod and piston out, you can push the crank out the rear of the engine. Heat the engine with a heat gun, torch, or in an oven to about 250-300 degrees F. The bearings will fall right out.

To reinstall new bearings, heat the case and push the cold bearings into place. Slide in the crank and install a propeller. This will pull it all together.