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Old Feb 21, 2012, 08:19 PM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
195 Posts
Help!
OS Max .40 rc

I have boiled (anti-freeze/crockpot method) for 1 1/2 days. Have everything apart, EXCEPT the wrist pin/piston.
Please someone out there with lots more experience (than me), tell me how to get it out. I have tried a SMALL easy-out, but no luck so far.
I want to take piston out and replave the ring, But I'm not smart enough, engine has done me in!
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Old Feb 21, 2012, 10:55 PM
Rocky Mountain High and Higher
PROACE's Avatar
Joined Jan 2002
877 Posts
Try heating the piston with a small torch but dont melt it! and the pin should press out easy with a drift punch of the correct diameter. remove the teflon buttons first if the engine has them.
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Old Feb 22, 2012, 02:55 AM
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Joined Jun 2011
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You can't just press it out. It has to be removed from the hole in the case. The plastic buffer needs to be removed and the pin pulled out, I use a pin or a piece of hardened music wire with a small hook on the and slowly work it back and force until it slides out. Heat will help. A small ez out should work too.
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Old Feb 22, 2012, 10:17 AM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
195 Posts
Thank you!

I will try with the little hook, then maybe I can get it out of the crancase.
Then I should be able to push it out.


Quote:
Originally Posted by datsunguy View Post
You can't just press it out. It has to be removed from the hole in the case. The plastic buffer needs to be removed and the pin pulled out, I use a pin or a piece of hardened music wire with a small hook on the and slowly work it back and force until it slides out. Heat will help. A small ez out should work too.
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Old Feb 22, 2012, 02:57 PM
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Isen´t there a G-clip at the end of the wristpin? Depends on the model, but it could be...
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Old Feb 22, 2012, 04:16 PM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
195 Posts
Sorry, Iv'e never heard of a G-clip, all you can see of the wrist pin is through the little hole on back side of crankcase.
10 minutes later: went looking for G-clip, still did not find it. But I giess this was not there, tried with easyout again. The wrist pin came out.
Thank you all for all the info, I guess I need to boil again, it's nasty looking now that I can see the piston and both rings.
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Old Feb 22, 2012, 04:31 PM
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There is no "G-clip"_ or c-clip on the OS 40R/C..The little nylon buffer things keep the wrist pin from rubbing on the cylinder.
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Old Feb 22, 2012, 04:47 PM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
195 Posts
The little nylon buffer things may have boiled away, if I can't find any? is this engine worth rebuilding???
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Old Feb 22, 2012, 06:53 PM
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Quote:
Originally Posted by Transplant92 View Post
The little nylon buffer things may have boiled away, if I can't find any? is this engine worth rebuilding???
the little teflon thingies won't melt away with boiling water.If they'll stand upper cylinder heat,they'll thrive in hot water.
We can't see the engine to say if it's rebuildable...look for scratches in the cylinder wall near the exhaust,and scores in the piston sidewalls.Is the ring stuck in the piston?
If you need to replace all those parts,it's prolly just as cheap to get a new one.
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Old Feb 22, 2012, 09:32 PM
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Singapore
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They are probably made of teflon. You can use small brass tacks with the heads trimmed down to replace lost or broken pads.
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Old Feb 22, 2012, 09:38 PM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
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Rings are not stuck (antifreeze boilng helps that). There are NO scuffs on sleeve or anywhere else inside cylinder. I guess I got lucky.
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Old Feb 23, 2012, 11:16 AM
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Belgium
Joined Aug 2004
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Quote:
Originally Posted by Transplant92 View Post
I have boiled (anti-freeze/crockpot method) for 1 1/2 days. Have everything apart, EXCEPT the wrist pin/piston.
Please someone out there with lots more experience (than me), tell me how to get it out. I have tried a SMALL easy-out, but no luck so far.
I want to take piston out and replave the ring, But I'm not smart enough, engine has done me in!
Using an appropriately sized small round file can sometimes do the trick, you insert it until it grips and you then try to pull out the wristpin, carefully not moving sideways or it will break off, this has worked for me quite often
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Old Feb 23, 2012, 10:37 PM
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Joined Feb 2012
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I am new to this forum or forums in general but have been in the rc hobby for 30 plus years and have never seen the boiling in antifreez thing. I just soak my engines in old glow fuel for a few days and they come out all unstuck and freed up. I have bought many a engine that folks thought were junk because they were seezed up from sitting for years.
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Old Feb 25, 2012, 01:40 AM
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Quote:
Originally Posted by epoxyearl View Post
the little teflon thingies won't melt away with boiling water.If they'll stand upper cylinder heat,they'll thrive in hot water.
We can't see the engine to say if it's rebuildable...look for scratches in the cylinder wall near the exhaust,and scores in the piston sidewalls.Is the ring stuck in the piston?
If you need to replace all those parts,it's prolly just as cheap to get a new one.

It may not have the nylon buffers. The wrist pin may have bronze ends that serve the same purpose
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Old Feb 25, 2012, 05:09 PM
Transplant in 1996
United States, NE, Scribner
Joined Aug 2011
195 Posts
They were bronze, I got it apart and now have it flying, The antifreeze method is what I was told to do. I tried the glow fuel soaking, it worked but the antifreeze cleans it like brand new aluminum. And it's a little faster.
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