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how do i remove seized pistons from cylinder head CA77 t-II

G-GAURD
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Location: highland,ca.

how do i remove seized pistons from cylinder head CA77 t-II

Post by G-GAURD » Thu Jul 22, 2010 7:39 pm

i bought an extra engine to get familiar with the break down and rebuild of my project bike. it's a used motor and the pistons are seized in the cylinder. i would like to try and free them up and replace with new pistons and rings but pulling the head and cylinder is a problem does drilling a circle of holes around the connecting rod and busting the piston rod free from the piston skirt sound like my only option????

any help is greatfully appreciated

Pete

CA77 type II

joeweir1
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Post by joeweir1 » Thu Jul 22, 2010 9:36 pm

Did you pull the head yet?

rustywrench
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seized pistons

Post by rustywrench » Fri Jul 23, 2010 12:35 am

Pete,
Drilling the tops off has worked for me but a worse case scenario. This would lead to drill shavings in the bearings and they are not easily removed for cleaning.
That said, I would advise reading some posts between me and Dr. Frankenstein where he unstuck his eng and you will find there a few helpful ways to get them to move without drastic measures. I have had to go to the extent of hanging the eng. by a chain and driving the pistons down with a 1 3/8 deep socket and a BFH which ended up driving the sleeves out of the block. Brutal but by God it came apart. Be patient and you will prevail. RW

G-GAURD
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Joined: Tue Jul 06, 2010 1:37 pm
Location: highland,ca.

top of pistons/cylinders got some rust

Post by G-GAURD » Fri Jul 23, 2010 4:16 am

yes i totally agree that drilling is a last resort. i have cut the cam chain and removed the head.the bright side is that this engine is a spare and its sole purpose is to give me some experience so i don't blow it with my good engine. i intend to completely disassemble the engine and split the case. i hava great mechanicle abilitys and worked with my father as aerospace machinist and tool & die maker and yes i have a manual but that hanging the engine and pounding the pistons sounds like my next move so i'll probably be stacking some matresses for a nice soft landing pad.

once the head was removed i could seperate the cylinders from the block so i know the shaft is'nt siezed cause i get about 1 1/2 of rotation and seperation from the block. so i figure about 10 min. of pounding a wood dowel after letting the pistons soak in some liquid wrench for a couple of weeks.

thanks for the hanging tip and i will keep you posted with some photos of pistons in cylinder and seperation gap from block

take care

Dr. Frankenstein
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Post by Dr. Frankenstein » Mon Jul 26, 2010 8:28 am

Hey, G-Gaurd, how's it going? (Or should I say 'what up, G??' :)

If you can get separation between the head and block, you might try shimming it up and 'tapping' on it with a piece of wood; but because of the position of the piston rods, and depending on where the pistons are (TDC/BDC, etc), and as I found out when I finally got the pistons Out, I noticed that didn't really do any good, at least for me. Not to mention the force of any pounding will get transferred to the main shaft through the piston rod itself, and *I* particularly didn't like the idea of all that force being transferred to a 46 year old piston, cast iron rod and almost-irreplaceable main shaft...

What finally worked for me, after letting it soak in PB Blaster, and then kerosene, for at least a week and then digging all the crap out from around the piston head to let the kerosene in there to permeate the 'seal', was banging it up and down with the rotor magnet. I just got pissed that it was stonewalling me and decided that it wasn't going to get any broker...

So using the gap I had between the head and block, I just said Eff-It! and flipped the rotor back and forth BAM-BAM-BAM-BAM, and noticed the pistons moving almost imperceptibly down in the cylinders, shimming it up as the gap got wider, until FINALLY they came free...and there was much rejoicing...I also found that liberal use of Colorful Invective enhanced the experience, at least for me...

This is what worked for Me. You're lucky you have a separate engine, and IMO I would go carefully, as these engines don't seem to be just laying around everywhere and any spare parts I'm sure could certainly be used by somebody somewhere...but Hey! If all else fails, bang the hell out of it!

-John

G-GAURD
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Joined: Tue Jul 06, 2010 1:37 pm
Location: highland,ca.

full release/ happy ending

Post by G-GAURD » Tue Jul 27, 2010 11:44 am

bam bam
i stuck a wedge between block and case and wedged it out with wood so i didnt damage any gasket surfaces...woo hoo... so im off and running on the next steps.

thanks everyone

Pete

real_psyence
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Post by real_psyence » Wed Aug 04, 2010 10:03 pm

Not to revive an old thread, but this is very relevant to my current situation: engine completely seized.

I don't think I can even get separation between head and cases at this point - I was hoping to find someplace I could attach a wrench/breaker bar to the crankshaft and try and move it back and forth while adding penetrating oil.

I see Dr. Frankenstein used the rotor for the alternator - is that the best place? I can't seem to figure out how to remove that either, so for now, it looks like it.

Thanks!

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