Will bead blasting a four stroke OS FS 61 or a two stroke OS 61 FSR likey to cause any issues? If the intake and the exhaust are covered up, i can't think of any places where dirt can enter the engine. What are your thoughts?

Thanks

They'll get in between the prop driver / case gap...
If you are going to clean them, there are easier ways that are less potentially harmful to the engine.

Dawn power dissolver, or the antifreeze in the crockpot method...no disassembly required...(except maybe to remove the carb )

What size beads? Some will make it pretty rough. Anything that was shinny will not be after.

I would never attempt to bead blast an assembled engine.

It is amazing how those beads can enter every nook & cranny.

I have bead blasted a few engines in the past. I would not recommend it unless you fully disassemble it down to the crankcase only. The finished product will have a slightly darker, more dull appearance to it as compared to a new engine. I like to do this if there are engine mount marks, polished areas or other scuff marks and desire a uniform finish.

Lately, my preferred method is a crock pot w/antifreeze.

I have tried bead blasting an ic motor that was very stained and had a lot of baked on oil, this came about after reading in an Australian rc magazine (a few years ago) about cleaning ic motors with a bead blaster, the idea was to use very fine beads ie baking powder/soda as this was found to be perfect for the soft alloy of ic motors. i made a gun out of an air duster and added a pick up line like an in an atomiser and put this line in the soda it was very simple but the results were really good, 10min work to make an os91vrdf look new and the finnish was very similar to brand new. Greg

Thank you for the replies, guys.<div>
</div><div>proptop, wouldn't the crockpot method lead to bearing corrosion or rust? </div><div>
</div><div>TFF, i don't have any idea on what sized beads i was going to use. I was thinking of taking the engines to a local shop and see how things work out.</div><div>
</div><div>Gregor32, did you find soda in places where you didn't want to be after you blasted the engine with it?</div>

Reading further, i think walnut shell media would be better compared to glass beads.

The crock pot method doesnt hurt the metal unless you leave it in for days, the aluminum will turn a dark grey. No problem on bearings. You rinse real good then oil immediately. I prefer to disassemble my engines before hot dipping.
Edwin

Sorry engines360 i cant remember if the soda got stuck anywhere, i did thoroughly rinse and clean with alcohol before oiling and reassembly. Greg

At least the soda is water soluable.

No grit left behind after rinsing.

I have glass bead blasted engines a dozen times or so and it make an OS look fresh out of the box. It's best if the engine is disassembled because the blast can lift away taped/masked areas, then you really have problems. The beads will also take the black oxide off the screws. Once the engine is disassembled, I like to put the head and case cover back on using "sacrificial" screws. This helps preserve sealing surfaces and keep the beads out of the tapped holes. Avoid blasting the front bearing bore by starting an old bearing in it and stuff a dowel in the carb's throttle bore. The one down side to bead blasting is it will "take out" any shined finishes such as fin tops, names/emblems.