I took my engine apart to change bearings and clean. I put it all back together and it was incredibly stiff. Turns out the con rod is seized on the pin that holds it in the piston. I popped the rings out but can not get the pin out of the assembly. It's been sitting in PB Blaster for a few hours and still no luck. Any thoughts?

I can post a pic later, but it would be of the con rod inside the piston with the pin sticking 1/4 of the way out of the assembly. I do not have a complete workshop (i.e. vice) just a few hand tools (and a dremel...[>:])

It's an OS 46AX. I don't know what the parts are made of (is there a sleeve?)

the wrist pin floats in the small end of the conrod...it also floats in the piston...you probably have a build-up of gunk under the piston and on the wrist pin...after removing any wrist pin retainers, if any, you should be able to tap out the wrist pin with a suitably-sized center-punch, or something similar (like a 3mm ball driver.)...hope that helps...ken

I've been tapping and tapping and it got to a point where it just won't go anywhere. I'm contemplating trying the freeze or the oven...

Gummout (or equiv. ) carb cleaner will probably take care of the problem...unless it's rust and not varnish.

You should be able to tap it through with the ball driver though...even if it is a bit gummed up.

If you don't have any carb cleaner, try heat.

Thanks. I think it's rust. There was a decent amount of rust inside the engine and the parts were soaking in power dissolver for a couple of days so all the varnish is totally gone.

Carefull on the tapping, I just rebuilt a Magnum 91 four stroke. I lost one of the teflon wrist pin end caps and after searching for hours, I made a replacement. When I went to assemble the engine, I couldn't get the wrist pin in. The piston had a setp in the bore for the wristpin and only had one teflon cap. You may want to check the piston to see of both holes are the same size befor trying to tap it out.

Something like a frozen pin is going to take something more than Dawn PD to free up. It effectively has a seal and will not let the stuff penetrate to clean up the problem. My suggestion is to put the piston and pin, Or whole engine if it is still inside in a big jar of Acetone and let it set for a couple days. Make sure you have a lid on it.

In stead of trying to tap the pin out, try a small ezyout or a disposable tap that will catch in the hole in the pin and try to turn it. Once you get it turning, you can get the solevent into where it will do some good and things will work from there.

Don

three more suggestions, and i'm outa here...
1. liquid wrench (made by gunk) works for me
2. if the wrist pin can't be tapped out in one direction, try the other
3. use a bigger hammer
-ken

Great, thanks guys.

Joe,

If you can locate some Evapo-Rust it will desolve the rust. I used some on a Veco .19 piston that was surface rusted to the liner. Work great! The stuff is non toxic and has no fumes so you can use it indoors. Have used it with the same results on other engine parts, bicycle parts, etc.

Terry in LP

ok...i lied...i'm back in...liquid wrench (available at any hardware store, wally world, etc.) is great stuff...a few drops will free a stuck piston ring, and if you work the ring in the groove, it'll clean them without risking breaking the ring by removing and replacing it...but the best part of liquid wrench is the way it cleans engines just as good as boiling it with anti-freeze in a crock pot...ken

http://www.gunk.com/prodinfo/L116.PDF

Heat will sometimes work to free rust as well, but first soak some penatrating oil on it for a few days. That way it smells much better in the oven.

....

I like your thinking Funny thing is I was using it thinking it smelled pretty good, so I read the label:

"Inhalation of this product, intentionally or otherwise, may cause death without warning."

I figured I should maybe open the window.[&:][&o]