BrickitSAM

I already did the spray with a toothbrush, it used to look a lot worst, I used greased lightning because it basically the same thing, I'll soak it on some LA, what should I do about the inner bearing?

1QwkSport2.5r

For peace of mind, replace both bearings. You will probably need to remove both bearings and measure them to get the proper size replacements. Bearings are catalogued by their ID x OD x Width. When you search for bearings, use that format to find the proper bearings. Some Asian and European engines use an SAE seized front bearing - like the R6 and a metric rear bearing.

aspeed

I would see how much play is in the bearing, and put in some thin oil. If it feels smooth, I would use them as is. It is only a beater motor that doesn't rev high. I have only needed to replace bearings about three times over 45 years. Two were worn badly, and one cage separated. A couple hundred motors. Lots of guys change bearings before their time IMHO, and normally the old rear one is ruined when it is taken out.

1QwkSport2.5r

I've replaced a lot of bearings in used engines that were obviously treated badly. I haven't had to replace any bearings in any engines I owned and ran from new. When dealing with an old crusty one, I replace the bearings for peace of mind. What's the big deal in spending 8-12$ on a little peace of mind. To me, a $50 used engine is worth it with a new set of bearings - especially a ringed engine. Realistically, you shouldn't need to replace them again provided the engine is treated right afterward. But that's just me. I do agree to a point - if the bearings are smooth and not gritty in the least to run it as is. But if there is any hint of grittiness or looseness, I replace them without a second thought.

aspeed

I think this one was free. Bearings would take a couple weeks to get in. All the bad bearings I had were from swap meet motors. Ya, if they feel rough, then new ones for sure.

BrickitSAM

Just soaked it in LA cleaner for about 2~ hours, man what a difference, the engine looks so much better, but outer bearing looks worse because some old blue lock-tight that was on the carb I could not get off and soaked with the rest of the engine got on it. The inner bearing rotates about 90* then stops, I have no hope for it Haha. The carb is still seized, going to soak it on carb cleaner tomorrow, how long should I soak it? also will the LA cleaner etch the metal? if so I dont want to soak it overnight.

aspeed

One guy on a forum said his engine turned grey with the LA stuff overnight. I would not soak it too long. Rinse it and spray WD 40 or whatever, so it does not go chalky. I had that. I soaked my carbs for 10 minutes or so. As soon as it moves, things get better. Getting it to move can be hard. A bit of heat helps, but I have not needed that yet. Looks like bearings too. Too bad, so sad.

Hobbsy

My Feedback: (102)

I just drilled the piston on my SilverLine .40 for bronze bushings, the original wrist pin bores are/were elongated, guess what, it has the wrong connecting rod in the box. No joy there.

BrickitSAM

New pictures of the thing cleaned https://imgur.com/a/iPqCW , I sprayed it with WD-40, sprayed it off with compressed air, used a paper towel to dry it off, then used some thin 3-in-1 oil to grease it up for smooth operation, that made it turn super smooth. I then used a heat gun to warm up the crank case to be able to separate the sections, it took about 1 min's of heating then it just came off super easy. After the case came apart I oiled the inner bearing a bit more and now its super smooth, I don't feel any graininess or looseness. The crankshaft is not coming out yet, might have to heat up the bearing or press it out which I don't want to do. The piston cleaned up super nice and the piston rod feels like its in good condition.
I'm going to try to get the bearing out now, what's the best tactic?

aspeed

If it is smooth then you don't need to remove the crank really. Small taps on the end usually get it out. Big taps can dimple the bearing. Came up pretty nice from the turd you started with.

Hobbsy

My Feedback: (102)

Based on your picture maybe I have the correct con rod, one end is longer than the crank pin and the other is shorter, was the wide end up or down in yours? Thanks, Dave

BrickitSAM

The wider part was in the piston, the skinny part was on the crank.

Hobbsy

My Feedback: (102)

Thankyou much, Dave

Nitrovein

Oiling the bearing will fool you, it needs to be perfectly smooth when it's completely degreased, otherwise it needs replacing.

BrickitSAM

OK, what's the best way to remove the press-fit bearings? heat the case till they come out?

1QwkSport2.5r

Yes. Usually it takes 325-350F to get them out; sometimes it may need to be as hot as 400F to get them out. . An oven works best for really gunked engines. Heat the case for 15-20 minutes and back the backplate on a block of hardwood. If it doesn't come out in 2-3 whacks, heat it more - a little hotter and a little longer.

Hobbsy

My Feedback: (102)

I have mine reassembled with the homemade bronze bushings in the piston. I had bought an assortment of K&S tubing ends of various lengths. I bored the wrist pin holes in the piston, the wrist pin was a perfect fit for the inside ID of the bushings. It has wild compression, definitely not a low nitro methane engine.

aspeed

A guy in our club had one with probably hundreds of hours on it. Absolutely no compression, took a starter 20 seconds of spinning to get it to fire. He would fly it till it ran out of fuel, and it would feather down to nothing over a long time. You really could not feel any bump at all. It was cowled, and likely ran very hot, as it was black. He flew it a lot for years. Good strong runner too, only slightly less than a schnuerle. The bearings should come out easy with a bit of heat, as it has a removable front. If you think it is needed.

Hobbsy

My Feedback: (102)

I don't have a muffler for mine but my LA .46 muffler fits, I lucked out since the LA .46 wears a Bisson Pitts muffler.

BrickitSAM

Well, I forgot to remove the crankshaft, silly me haha. I tried to remove it and the crank and rear bearing came out, I used the heat gun for the front, the bearing is rusted-stuck to the crank. I tried heating up the bearing with a heat gun and got it super hot, no luck. I then sprayed some penetrating oil onto it, its helped a little, I got about 0.5mm of movement from gently tapping the bearing around the cam, not a very good way to do it. I called it a night and put some more penetrating oil on it, stinks the bearing wont stay in the crankcase because of the 2 part design.

BrickitSAM

Progress update, I heated up the bearing and crank to 350F and let it sit for about 10mins to let it heat up thoroughly, I took it out, then used a socket and hammer to reach the bearing, I pounded it for and while then repeated that 2 times. I have gotten about 1millimeter of progress, that sucker is super stuck, its in the oven now waiting to be beaten again, I just hope I don't break the crank.

BrickitSAM

Progress update 2, I got the bearing off, took about 4-5 re-heats then I used a puller to do the rest, there's a little carbon buildup, going to clean that off best I can, just getting bearing sizes now.

jaka

Hi!
You should have hit the crank case against a piece of wood laying on the concrete floor imidiately when you heated the crank, not waiting!
This way the rear bearing will fall out. If it doesn't fall out cool the crank case in water and repeat the heating process, preferably with a propane torch!

BrickitSAM

That would not have worked because of the 3 piece design, also I would never put it in water, that weakens the metal, your rapidly cooling down the outside and the inside but the middle is still hot so it develops stresses.

1QwkSport2.5r

Using a torch isn't a good idea either unless you really know what you're doing.