Author Topic: Case re-assembly questions and advice (Read 4407 times)

timbo750 · « **Reply #25 on:** October 27, 2013, 08:49:11 PM »

Cakey, just to give you an idea on postage to AUS. I got some gearbox parts recently from the US, $50 for the parts and $130 for delivery and was less than in weight than a crank and rods. however it was still cheaper than the price I got over the phone from Puds and he was only talking a couple of gears, I got the shift drum and shafts as well.

cakey · « **Reply #26 on:** October 30, 2013, 03:22:35 AM »

Got the new crank and rods on eBay USA. Heaps cheaper than anything in OZ. As you can see the new crank has not got the advancer shaft and I cannot get mine off yet. I am thinking about using heat plus it looks a bit bent. Is there a trick to getting them off or can you straighten them or do you buy another. Now I wait.

cakey · « **Reply #27 on:** October 31, 2013, 02:10:08 AM »

All right I have tried to remove the advancer shaft off the crank by using heat, vise grips and the double nut. No success.

I would rather take a break and see if anyone has any suggestions. I thinks I have bent it a bit and don't want to do anything further. I see that you cannot buy them anymore.

If I could buy a good second hand one I would just screw that onto the new crank.

Help. Suggestions?

Ace · « **Reply #28 on:** October 31, 2013, 04:26:09 AM »

There is a guy in Darwin who goes by the forum name Mick7504. I've met him a few times, he might have some spares or know a mechanic to get machine work done etc. PM him.

I took my K1 to Alicross, met the owner (can't remember his name for now) who did his apprenticeship on the 750/4. He doesn't really do old bikes, depends on what you need done. I was in Katherine so bugger all I could get down there. I also took my head to him to cut seats, lap valves and milled the head (by someone else).

cakey · « **Reply #29 on:** October 31, 2013, 06:03:54 AM »

Quote from: Ace on October 31, 2013, 04:26:09 AM

There is a guy in Darwin who goes by the forum name Mick7504. I've met him a few times, he might have some spares or know a mechanic to get machine work done etc. PM him.

I took my K1 to Alicross, met the owner (can't remember his name for now) who did his apprenticeship on the 750/4. He doesn't really do old bikes, depends on what you need done. I was in Katherine so bugger all I could get down there. I also took my head to him to cut seats, lap valves and milled the head (by someone else).

If you did Katherine and survived I take my hat off to you mate. All my machining work is done now so I am just stuck on this stud. Got a fee
Inge that Terry in Australia might have mentioned Mick in Darwin. If I can't get this thing out I will give him a PM. If it's the bloke I am thinking about he works on the mines.

Alicross rings a bell I think they are still going.

Good too hear from someone from the Top End.

iron_worker · « **Reply #30 on:** October 31, 2013, 08:16:49 AM »

Are you heating the stud or the crank? The best way would be to concentrate the heat on the crank ... however you wouldn't want to direct a lot of flame onto the bearing surface. Obviously, you want that to be a nice polished surface for the bearing to mate with.

I wonder if putting the whole crank in the oven at 350F or so to get a nice even heat on it would help? You could also then try cooling the stud with a wet rag to try to shrink/shock it a bit. Or I've also seen people use those cans of compressed air to cool valve guides. I believe if you hold them upside down the propellant comes out and gets very cold as it expands.

Just thinking out loud and hoping something here helps you out.

IW

cakey · « **Reply #31 on:** October 31, 2013, 02:07:31 PM »

Thanks Iron Worker. I got a big oven in the bakery to use and I use those freeze sprays with my chocolate wrk, so no harm in giving it a go. Thanks

timbo750 · « **Reply #32 on:** October 31, 2013, 02:36:19 PM »

mmmm, chocolate coated crank, not good for the teeth.

Ace · « **Reply #33 on:** October 31, 2013, 03:18:11 PM »

Quote from: cakey on October 31, 2013, 06:03:54 AM

Quote from: Ace on October 31, 2013, 04:26:09 AM
There is a guy in Darwin who goes by the forum name Mick7504. I've met him a few times, he might have some spares or know a mechanic to get machine work done etc. PM him.

I took my K1 to Alicross, met the owner (can't remember his name for now) who did his apprenticeship on the 750/4. He doesn't really do old bikes, depends on what you need done. I was in Katherine so bugger all I could get down there. I also took my head to him to cut seats, lap valves and milled the head (by someone else).

If you did Katherine and survived I take my hat off to you mate. All my machining work is done now so I am just stuck on this stud. Got a fee
Inge that Terry in Australia might have mentioned Mick in Darwin. If I can't get this thing out I will give him a PM. If it's the bloke I am thinking about he works on the mines.

Alicross rings a bell I think they are still going.

Good too hear from someone from the Top End.

My shake down ride was to Kununurra and back. I miss the NT, outdoors, barra fishing, near open speed limits.

Mick works at a brake shop near the Winnellie Hotel unless he's moved on.

Have you tried to tighten the points shaft to crack the thread and then loosen it? I've done this with stuck bolts, spark plugs to break the thread seal. Usually the two nuts and multi grips gets it off.

I'm rebuilding a K2 engine at the moment, what are you after? Yamiya750 is where I get most of my parts from, not the cheapest for some things but postage is good and usually within 5 days as well.

I got a quote from CB750 Supply for the penny washers under the cam towers worth $10, postage $100 to Oz. They're not the only robbers out there for postage and US CB750 suppliers are loosing out in business from Oz.

cakey · « **Reply #34 on:** October 31, 2013, 03:21:44 PM »

Does it just done up like a standard thread (turn right to tighten and left to loosen) or is it like a gas fitting and is oppossite?

If not I will try what you are saying and go to tighten it up and then loosen.

martin99 · « **Reply #35 on:** October 31, 2013, 04:38:17 PM »

Others have had success holding it as close as possible to the crank with vise grips and turning it out, using aluminium shims to prevent damaging it. Or a stud extractor which gives a broad grip.

dave500 · « **Reply #36 on:** November 02, 2013, 07:15:50 PM »

its a right hand "normal thread"anti clockwise undoes it.

Ace · « **Reply #37 on:** November 02, 2013, 09:41:59 PM »

Quote from: dave500 on November 02, 2013, 07:15:50 PM

its a left hand thread,clockwise undoes it.

Incorrect as I've just taken one out last week. Right hand thread so right is tight and left is loose on the CB750 SOHC

dave500 · « **Reply #38 on:** November 02, 2013, 09:48:49 PM »

yeah ive just spotted that,a freind of mine just gave me one to give to cakey and told me they have a left hand thread,i just had a look and its definetly a right hand,post modified,thanks ace!

also turns out he has a few 750 cranks if anyone else in australia needs one?he has a pile of heads aswell.

cakey · « **Reply #39 on:** November 18, 2013, 02:21:57 AM »

Luckily I received the advancer shaft in the mail from Dave500 and installed into the new crank. Couldn't let it stop bugging me though that I could not get the old one out so I bought a Stanley Stud remover and I tell you what I am amazed how that thing worked. I got out the old stud in 5 second flat and the threads were stuffed and it looked like someone had used some type of loctite or something to glue it in with which explained a lot.

Those Stanley stud removers are amazing but they did leave a mark on the shaft.

cakey · « **Reply #40 on:** November 18, 2013, 02:30:39 AM »

Thought I would have a crack at putting it all together last weekend but the Amateur Mechanic Demond's were looking over my shoulder.

Thought I would torque the rods on first and check with the plastiguage again because of the new rods and crank. Have all new black bearings. Everything was going well and I cleaning the plastiguage off the last bearing shell inside the rod cap and felt something. Had a closer look and it was a hairline crack in the new shell. I don't know how it happened or why but that was the end of that. I have another one coming up from Melbourne this week. I kept going and plastiguaged all the main bearings while I was waiting and every bearing is even closer than the old crank. Everything falls between .025 and .035 now.

You can see the hairline crack running across the bearing shell. Iam hoping it does not happen again.

Cleaned the oil pump and stripped it down. Got new seals and strainer coming. Finished polishing the fork tubes and put the forks back together with new seals and oil. Keeping myself busy whilst waiting.

It's like this engine does not want to be put back together.

dave500 · « **Reply #41 on:** November 18, 2013, 11:33:59 AM »

i cant see it clear enough but you sure its a crack not just a mark?its very malleble metal?

cakey · « **Reply #42 on:** November 18, 2013, 12:45:46 PM »

Yeh definitely a crack. Looked under the magnify glass. Couldn't believe it.

cakey · « **Reply #43 on:** November 22, 2013, 10:27:59 PM »

Just wanted to double check before torquing the cases together. It looks a bit odd that one primary chain hangs slightly lower than the other. New chains and out the same packet. Just checking?

dave500 · « **Reply #44 on:** November 22, 2013, 10:32:00 PM »

was is it a cheap chain set?im not a 750 guy our 500/550s run a heavier hyvo type primary chain.

cakey · « **Reply #45 on:** November 22, 2013, 10:39:30 PM »

It's genuine specification OEM chain set from CSMNL. It did the same thing on my old crank before I put the new crank on so I am thinking its normal but just double checking.

dave500 · « **Reply #46 on:** November 22, 2013, 10:46:17 PM »

a 750 guy will chime in shortly,maybe once the case is closed and bearings squared up properly itll even out?

cakey · « **Reply #47 on:** November 22, 2013, 10:48:32 PM »

I was thinking that myself Dave as well as the pressure from the tensioner roller. I am sure there would be a reason.

cakey · « **Reply #48 on:** November 23, 2013, 08:50:05 PM »

Well I just kept going ahead with putting the case together. We have a cyclone headed our way at the moment so it gave me an excuse to tidy up under the verandah a bit more.

Everything seemed to tension up better when the case halves went together. Put the top and bottom bolts on and started the paint job.

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Author Topic: Case re-assembly questions and advice (Read 4407 times)