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Alright, so I'm starting to break into the crankcase. As I've stated before, this freaks the hell out of me, but I have the tools I need to do it. I got the pistons off ok, although I think I lost every single one of those little clips that holds the piston pins in place; they shot off when pulled them out. Hopefully those are very easy to replace :0

I got the pins out enough to take the heads off, but they're not coming out fully. Advice?

Also, and here is where the pictures come in, the rods are beat to hell. They've got nicks and damage all over. I don't know what to make of it, is this extremely bad? Should these suckers be replaced?

And now for the pictures:





Here we can see inside the crankcase, and you can in that earlier shot too. Is that rust inside there? What in gods name is that gunk?


As always, the help is appreciated. I've been reading a book on how to restore old bikes, the service manual, etc. and this stuff is fairly daunting. I'm worried about the gear timing, especially marking them. Would a sharpie do ok to mark the timing?

I'm trying to take the nuts off the clutch hub right now, and holy hell is it a *****. I'll be posting more pictures of things as I get into this, and asking advice on what parts need replacing.

I swear, If I get through this engine, get it back together, and everything fires up in the end, I will be ecstatically happy. I'm thinking about taking it to a local guy to rebore things, and redo the valves. He does work for $25 an hour, as it's more for fun. Bastard wouldn't let me borrow his specialty tools thought :p
 

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someone has been letting the rods contact the cases.if you cant polish those marks out,they may well break.even with polishing,the rods might have stress in them and could break anyway.rods are expensive but it looks like you need new ones.the piston circlips have to be replaced every time.you could make a pusher out of old bolts and sleeves of hollow rods or a deep drive socket to push the piston pins out.light heating of the pistons will assist this.
during the build,dont forget to clean the sludge trap in the crank.hardest job building these is getting the gears to index right.make sure all the gears are there before you put it back in the frame
 

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All I can say is:

GO STEP BY STEP, EXACTLY ACCORDING TO THE BOOK.

If you do that, you'll be fine. Even better is a read-through, then a "dry run" where you read through again, fitting up the parts and checking that is seems to all fit properly, THEN the "real thing".

BEST ADVICE:

Do the above with BOTH: SHOP MANUAL AND PARTS BOOK.

You don't want leftover parts when you are done except 4 tab washers - alternator rotor, kickstart ratchet gear, drive sprocket, and clutch hub.

(and of course, and parts you replace with new)

I don't like the depth of those rod nicks; I'd replace 'em.

New pistons come with new circlips for the gudgeon pins.


[ This message was edited by: GrandPaulZ on 2007-03-05 09:29 ]
 

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#1 buy this video:

Hughie Hancox Engine rebuild video

Also, if you junk your rods save them and use them as a stopper for you fly wheel. If you cut the ends off of them and lay them down alongside the new rods after they are installed, you can stick a soft metal bar thru the new gudgeon pin holes and stop the fly wheel from rotationg when you tighten up the clutch hub bolt.
 

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While I don't recommend using the rods as leverage when tightening crank end nuts (alternator & timing gear), I'd rather re-insert the gudgeon pins then run a long rod through and block them up with a piece of 2x4 on either side of them to stop the crank's rotation.
 

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Paul, sorry for the confusion, but thats what I meant to say. I would lay the old rods across the case so the brace you put thru the gudgeon pins doesn't scar up the case. I suppose wooden blocks would be even better, though.

PS nice update to your site!
 

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You should be able to sand those nicks down and then polish the rods. You have the late "heavy" rods and even after removing a little of the material you will still have thicker rods than the TT specials ran, so that should be no problem. The nicks in the upper half of the rods, near the gudgeon pin holes, are not as dangerous as nicks down in the bottom half. Most rod breaks I have seen are at about a third of the way up between the big and small end. It's not the thinnest part of the rod, but it gets the most stress. You can reuse the rodbolts and nuts.
Do have the big ends checked for ovality and have them face ground and honed if necessary. Fit new pin bushes and have the new pins fit to the bush. Make sure to drill the oil feed hole in the top of the rod after fitting the new bush, and before pinfitting.
The goo in the crankcase is old clutch plate material, primary chain and sprocket material, burnt oil, dust and dirt from the breather, bits of metal from bearings and bushings, etc. And the other stuff is rust on the flywheel. The engine sat for awhile at some time in it's life, it would seem
It looks like the left inlet cam bush is protruding enough to be up near the lobe. You may need to replace the cam bushes, and that requires line reaming.
To remove the pins from the pistons, you should heat them a bit to see if it eases the removal.
Upon refitting the pistons, mark them left and right, and an arrow to face forward. Then put the inside clips in before fitting the pistons on the rods. Stuff rags in the mouth of the case to catch any errant clip.
You can make a piston support plate easily out of some thin plexi or plywood or even aluminum. Cut a slot large enough for the rods and it will sit on the cylinder studs and give a sold surface to support the pistons while you install the cylinders.

[ This message was edited by: Mecchanica on 2007-03-05 13:34 ]
 
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