I have an OS 46ax which I havent used in almost 2 years. Last I used it, it wa relatively new, about 6 months old. In preparation for one of my winter builds, I was looking through the exhaust port and noticed some grainy particles sitting on the piston head. So I decided to take the engine apart just to cean it all up before I ran it again. Well this is what I found - see pics. I dont have engine rebuild experience other than basic reassembly, so dont really know if its anything to worry about. Seems like very light corrosion on the back plate, crankshaft and rear bearing. How can I correct this? Could I just sand down with very fine sand paper or dremmel, would I need to replace? Any help would be appreciated. Im assuming the rear bearing will need to be replaced.

ro347......i don't know that i can tell you how to clean than motor up, or if you will just have to replace it.....what i can tell you is how to avoid this same thing from happening in the future......in my 25+ years of flying radio control i've alway's ran out all of the fuel at the end of the day.....fortuneatly for me, this is one of the first things i was taught when i joined a club and started flying rc.....unfortuneatly nitro has some degree of moisture in it and it is necessary to drain the fuel tank and run the engine dry at the end of the day to prevent rust inside the motor from sitting over long periods of time......also, one other thing you could do is buy some after-run oil and shoot a couple of drops into your motor "AFTER" you completly run out all of the fuel......the proper procedure for running out all of the fuel would be as follows......find a safe area to start your motor, run the motor wide-open, remove the fuel line that feeds the carberator and let the motor run wide-open until all the fuel runs out and the motor quits......now to lubricate and protect the motor from corrosion, remove the glow plug and shoot a couple of drops of after-run oil into the piston area while you spin the motor over, either by hand or with a electric starter, this will coat and protect the piston area and the upper-end of the motor.....now open the carberator wide-open and drop a few drops of after-run oil into the carberator while you spin the motor over, either with an electric starter or by hand, this will coat and protect the crank and bottom end area of the motor against moisture damage in the future......i hope this helps???....like i said, i can't do anything for this motor but, this little bit of info. might prevent this from happening again in the future......life is a learning experience and radio control is no different.....my dad used to say, there's nothing wrong with making mistakes as long as you learn from them, it's when you make mistakes and don't learn that you keep making the same mistakes over and over, that's bad......ro347, hang in there....it's thanksgiving holiday weekend.....everybody's eating turkey and celebrating with their families.....as soon as this holiday thing wears down i am sure somebody will jump in here and have all the right answers to your particular situation......we had family over too and if my wife would have caught me doing the RCU/internet-thing, she would've cooked my hide.....being that she's never flown, she can't understand why we can't leave it, not even for one day???....ha! ha! ha!......take care, ro347....i'll check back and see how your holding up......i have to wait out today(sunday), it's supposed to rain and then it's supposed to be warm and sunny and dry the next 4 day's......i'm getting all my s**t ready, i haven't flown in @ three week's.....i just got another plane built, balanced and motor tuned like a hawk and i'm dying to try it.....KOOLKRABBER47.......

__________________________________________________ ______

PRECISION AEROBATICS BADBOY V2 O.S. 46AX STINGER 12-4 WOOD PROP JR XP6102 COMPUTER RADIO

[quote]ORIGINAL: ro347

I have an OS 46ax which I havent used in almost 2 years. Last I used it, it wa relatively new, about 6 months old. In preparation for one of my winter builds, I was looking through the exhaust port and noticed some grainy particles sitting on the piston head. So I decided to take the engine apart just to cean it all up before I ran it again. Well this is what I found - see pics. I dont have engine rebuild experience so dont really know if its anything to worry about. Seems like very light corrosion on the back plate, crankshaft and rear bearing. How can I correct this? Could I just sand down with very fine sand paper or dremmel, would I need to replace? Any help would be appreciated. Im assuming the rear bearing will need to be replaced.


[/quote


P.S. HOBBICO after-run oil sell's for @ $2.50 a bottle plus shipping.....hobbico is only one of many companies that make it......i usually buy 4 at a time and make it an even $10.00 and to take advantage of combined shipping charges....i get mine from tower hobbies.....just a thought.....KOOLKRABBER47.....

use an sos pad wet to clean up the backplate and crank and replace the bearings.about $15 shipped for stainless
http://www.rc-bearings.com/catalog/p...roducts_id=715

The bearings are shot. the regular parts can be saved by removing the rust like whatiworks4 says. to replace the bearings put the new bearings in the freezer to get real cold and then heat up the engine block with the old bearings in it. the hot engine should allow the old bearings to fall out when you strike the engine on a flat wood surface. do not force the new bearings in with anything metal use big wooden dowels to protect the bearings. keep engine warm when putting in cold bearings

Thank you all!!! Im just glad it can be saved. It will be going into my first profile.

Hmmm....SOS pad, isnt that a bit aggressive? I wonder if dremel makes a steel wool disk, so I can get into corners and get a clean result.

Just ordered the bearings, $13.29 shipped. Big difference from the Oem cost, and these are stainless steel.

There isn't any real way to tell if you have a bearing problem or not from a photo, the color or even a little rust may have had no effect on them at all. Living in an area of the country that is humid you will often have a bit of a rust problem. Like Kool stated, I would at least run my engines empty at the end of the day. I'm not a big fan of after run oil but it doesn't hurt to give the engine a little shot at the end of the day. I would just clean your engine and put it back together and give it a try. Just oil up the bearings and give them a twirl then flush them with alcohol and oil them up again. If they are bad you can feel them grinding. Don't get too freaked over a little rust, it isn't the end of the world, clean it up and give it a try.

Thanks Gray!

Paraphrasing from a very reliable source ...

Bearing removal. Rear: heat the crankcase around the rear main bearing 'til hot (use a glove or towel). With a solid downward motion, hit the rear of the block against a pad of paper or a piece of leather. The bearing will jar loose. Front: heat the crankcase around the bearing, tap the bearing out with a wood dowel and a plastic hammer.

Bearing installation. Freeze the bearings. Rc-bearings ship theirs in nice small ziplock bags - just toss it in the freezer. Rear: Slide the rear bearing down over the crankshaft 'til it bottoms out. If it won't slide down because the bearing is cold and the crank is warm - freeze the crank too. Heat the case around the bearing seat. Insert the bearing-n-crank with a wood dowel inserted into the back of the crank. Then seat the bearing into the case and use a sharp blow of a plastic hammer to seat if necessary. Front: heat the case around the front bearing seat. Have a solid surface with a hole drilled to accept the front of the crank. Place bearing over the crank and position the assembly so that the crank will go into the hole, then use the wood dowel inserted into the back of the crank and a plastic hammer drive the front bearing into its seat.

A reassembly note: the connecting rod big end hole is flat on one side and beveled on the other. When you reassemble, the bevel is installed towards the back plate.

Another approach:
slide the main bearing over the crank & seat it.
freeze both bearings & crank.
heat the case in the oven at 300 degrees.
insert the crank into the warm case - the bearing may seat beautifully - make sure that you keep the bearing seated while the hot & cold items equalize.
slide the front (frozen) bearing over the crank and it may seat itself.

Thanks for the support guys. One more question: Once I remove the rust, what should I be coating the engine parts with during the rebuild stage?

I use air tool oil as my assembly lube applied with a q-tip. After run oil would work too.

ro347......i told you everybody would chime in here after they were done "power napping" from eating all that good turkey stuff......by the way, a q-tip work's good, so does an epoxy brush, i use the epoxy method, the bristle's get in to those crevises pretty good.....when i reassemble my motor, i sometimes use 3-in-one oil, because my other hobby is boat upholstery, i alway's tend to have some 3-in-one laying around, i use the 3-in-one to lube my commercial sewing machine,too.....good luck with the motor.....KOOLKRABBER47......

Thanks Kool!!! Just got back from Lowes and picked up an 8oz bottle of Air tool oil for about 2.50 and a couple of dremel polishing brushes. The bearings are on the way. So this should work out just fine. thanks again!

By the way....how do you like the power of your 46AX on your PA Bad boy with the 12x4? Im basically doing the same setup on an OMP ProYak.

i think the dremel would be too "agressive, especially if you leave it on one area too long.....kinda like sanding a car or a boat for painting, if you don't absolutely know what your doing, you could accidentally leave it in one spot for too long and gouge the paint in the process.....in the case of this motor, if you use a dremel and leave it in one spot for too long and pit the mating surfaces, you won't have the factory-fit and tolerance......you might end up with a loose, sloppy motor or leave a gap/loose-fit and end up leaking oil.....why chance it???....go with the s.o.s. pad's, keep them wet and let the soap do the work, if you run them dry, that's when the begin to scratch the metal......i think you made a wise decision going with the new bearings, why chance locking up the motor in mid-air for the meager price of the new bearings, in this case just $13.00......i don't know how long you been flying????.....for a seasoned pilot like myself, a dead stick is just a walk in the park, i could thermal around the sky forever.....for a newer pilot with average skill's and only one plane to his name, it would not be worth stuffing it into the ground over the price of a set of bearings???.....also keep in mind, from a safety stand-point, it would not be wise or sportsman like to put a plane in the air unless you are 100% certain it is airworthy......i know i alway's check my planes at home the day before i fly and at the field before i fly.....flying is cooool, accidents are not......KOOLKRABBER47......

________________________________________________

PRECISION AEROBATICS BADBOY V2 O.S. 46AX WITH STINGER 12x4 WOOD PROP JR XP6102 COMPUTER RADIO

Hey Kool - I soloed in 9 flights, 5 of which were dead sticks. Then there was the Evo 52 - 33 flights 23 dead sticks - needed a new carb. Yup, a walk in the park [:'(]

Ive been flying for 3 years now. I never place a plane in the air unless im very confident that its well tuned and ready to fly.

Thanks for the tips.

I LOVE IT???.... oh!, did i say that loud enough????.....low pitch prop is the trick and keep it very,very light.....something in the 12x4 size with minimum flex will work best.....these profile planes were not meant for speed, i've got other planes for that......the design factor behind the profile fuselage was to narrow the fusealage and allow as much air as possible to flow over the control surfaces(ailerons,elevator,rudder)......low pitch prop allows the motor to maintain high RPM's at all times and thus huge amounts of constant air-flow over the control surfaces at very low speeds, without too much forward thrust.....that's how these 3D'er's came about.....i like that i can bring this thing "low" and "inside", right down on the runway.....boy, you talk about "drawing a crowd"......i bring this thing right down on the runway and keep it moving the whole time, head over tail, tail over head and yet it stay's in a 10-20 foot envelope the whole time.....ro347, "ARE YOU DROOLIN' YET", HA! HA! HA!.....get that thing built brother, p.m. me brother, if i can be of any assistance.....KOOLKRABBER47.....

Hey Kool - just looked up Ilwaco, WA - wow, that's gotta be a slice of God's country. Love your contributions!

Got it all cleaned up...now a little heat to dry up any moisture. Question: Only 1 part left if I can figure this out - How do I get the connecting rod pin out of the cylinder. I pulled out the little clips in the cylinder, but cant get the pin to slide out. Tried tapping it, nothin!!!! Any ideas?

I GOT IT - placed it in the oven at 200 for 20 minutes and it popped right out.

yup, god's country......i'm right on the waterfront......the marina is right on my door step.....hence the nickname>>>koolkrabber.....i work on the commercial crabbing boat's in the winter: ala discovery channel......i also work on the charter fishing boat's in the summer....i promise i will attach some so,so photo's to this post.......SeamusG, i don't know where you live but, if your ever in the area, look me up, i'll take you fishing on the ocean for free....or pm me your address, i'll ship you some dungeness crab(overnight).....i hope i don't start a stampede by saying that.....i like fishing just as much as i love flying and on the coast i get to enjoy both......i live right on the marina, the boats are parked right outside my front window.....the funny thing is this place fell right in to my lap for next to nothing......my wife's boss own's the restaurant beneath my home and used to live in my home....they decided to build a house and when they moved into their new home, asked us to move into this home to keep an eye on their restaurant down stairs.....mind you we were offered the house for next to nothing,as "caretaker's" of the restaurant.....yup, god's country......oh,well! ever heard of karma......all those year's of helping other people, finally somebody took care of us......anyway's,we just started fishing today....spent the whole day dropping crab pot's into the pacific ocean, 500 in all.....we'll let them soak for 3 day's, tuesday they will be full of the ocean's bounty......take a couple of handful's of sweet creamy butter and a ton of crushed garlic, melted in a sauce pan and add a s**t load of crab leg's and oh well, you get the idea.....that's why they call it straight suffering, here on the washington coast???....KOOLKRABBER47.........just in case you haven't figured it out....i'm the old fart in the black hat....i try to hide my white hair's, cause the younger guy's get jealous......ha! ha!.......

So lucky!!! People say im lucky living 15 minutes from NYC....but I would trade for sure!

15 min from NYC lucky...lol not when you live out this way ro347! Born and raised back east, I'll only visit now! West side is where its at!

I've got an Enya .80 like that, wonder if I should give it a go?[&:]

Yer kewl s**t Kool! I hope to be that hip when I get there!

Something's been calling me to the west coast for some time now. Im hoping to make out out there at some point. Maybe even perm. Who knows! I was born and raised in NYC...now live just outside in Nj - Ive got grass and trees but just a 10 mile ride to Times Square in the heart of the concrete jungle. I love the diversity of NYC, and the fact that anything goes and ppl are allowed to be who they feel they are. But I just love the laid back, friendly attitude people have outside of the east coast. Its just a different world.


As far as the Enya - give it a shot. I completed mine in a matter of a few hours. It was very simple thanks to the help of those that gave advice here ( Thank you). I'll just have to wait for the bearings to come in, but have no doubt the engine will run just fine.

Stopping off in the Rockies ain't so bad either - just reduced HP ...