Author Topic: 1972 CB750 Four K2 -- Rebuilt to NEW OLD STOCK -- PIX ON PAGE 50 (Read 241140 times)

RRRToolSolutions · « **Reply #300 on:** January 21, 2014, 05:43:43 PM »

Ed, I've got a friend that has ordered from Yamiya and the experience and quality was "Great" according to him.

Just as an FYI -

Gordon

seanbarney41 · « **Reply #301 on:** January 21, 2014, 06:34:48 PM »

I would be really worried about that shop doing any machine work on your stuff. Think about it. These motors are NOT small block chevy's. Piston to bore clearance is extremely critical with these engines. They already said they don't want to work on mc stuff. Seriously, if there is no one local, just send it out somewhere. USPS is not gonna cost you that much more.

edwardmorris · « **Reply #302 on:** January 21, 2014, 07:21:38 PM »

Thanks Gordon, good to know.

Sean, the shop is a pretty reputed one and are known in the local old car resto enthusiast groups. I know cars are a different story but it would be easier for me to do things locally. The shipping is not all that cheap even with USPS, not to mention packaging also costs money. I will leave that as a last resort.

They are apprehensive about small twins/Vs and old British bike heads and such. Not really sure what happened but like Ron suggested, I'm guessing one bad valve job and someone came screaming at them.

The machinist examined the jugs and asked me if I wanted to bore to the next size. When I asked will you do it? He said get me the new pistons first so I know how much to do. I will be asking for help here and compiling an exact set of specs that I can hand him (I'm counting on Mark, Terry, Gordon and others here for help) and say it has to be done this way. Should he have any concerns, I will promptly bring it back home and look into shipping it out.

edwardmorris · « **Reply #303 on:** January 26, 2014, 06:25:31 PM »

Got some time to work on the bike after a looooong time. Got the connecting rods out and the crank is free but I couldn't for the life of me get the rotor off, even with two strap wrenches holding it down. Left it alone for now before I did any damage. Then scraped off as much of the hondabond on the top case, then the remnants of the jugs gasket.

edwardmorris · « **Reply #304 on:** January 26, 2014, 06:32:35 PM »

Also, tried the back to black on the rear fender after sanding it with 2000grit sand paper, looks nice despite the nasty gouges and scratches.

edwardmorris · « **Reply #305 on:** January 27, 2014, 10:43:24 AM »

As I ready the cases for blasting, I realized there is a bearing in the lower crankcase that I need to remove. I was planning on replacing all transmission bearings anyway, preferably with SKFs since I can literally drive down the street and pick them up. There are three special grooved ones that I'm having a hard time explaining to the SKF guys here. I searched around and also checked with Mark and NSKs are the next best bet and they do seem to have the grooved one, but I still do not know the exact numbers ans suffixes to specify when ordering replacements. Anyone have these?

edwardmorris · « **Reply #306 on:** January 27, 2014, 11:09:15 AM »

AND hello search!

http://forums.sohc4.net/index.php?topic=60026.0

2 x HK2520 Needle Rollers
1 x 3206ATN9 Roller Bearing
1 x 6003 Roller Bearing
1 x 6008NR Roller Bearing
1 x 6204 Roller Bearing
1 x 6205 Roller Bearing
1 x 6205NR Roller Bearing
1 x 6304 Roller Bearing
1 x 6304NR Roller Bearing

6304NR being C3 as pointed out by Mark...

I'd like at least one person who's used these to concur before I place the order....

iron_worker · « **Reply #307 on:** January 27, 2014, 11:11:12 AM »

Did you try an impact on rotor? You were using a rotor removal tool right (IE a bolt lol).

Hit the bolt with the impact then wrap the end of it with a hammer. Repeat. Should come off that way. Warming up the rotor would help too.

IW

edwardmorris · « **Reply #308 on:** January 27, 2014, 12:43:45 PM »

Quote from: iron_worker on January 27, 2014, 11:11:12 AM

Did you try an impact on rotor? You were using a rotor removal tool right (IE a bolt lol).

Hit the bolt with the impact then wrap the end of it with a hammer. Repeat. Should come off that way. Warming up the rotor would help too.

IW

Didn't quite get to using the puller, there is a bolt that needs to come out first. Will get back to it....

MCRider · « **Reply #309 on:** January 27, 2014, 12:48:08 PM »

IF it were still on the bike, you'd take a 3+ ft cheater bar to it. After putting it in 5th gear and cranking the rear brake all the way tight.

With the crank on the table top, if you had a big mutha vice you could chuck it up in. Or an electric impact wrench...

BPellerine · « **Reply #310 on:** January 27, 2014, 01:56:25 PM »

electric impact works great!if you don't have one most garages do and would most likely remove it for you it works fast and easy.bill

edwardmorris · « **Reply #311 on:** January 30, 2014, 10:57:57 AM »

No luck on finding a shop to widen the grooves on SKF replacements. Worst case, I'll leave the old ones in, or shell out for yamiya ones. Haven't had time to get back to the rotor yet but thanks for the tips Ron and Bill. Been working like crazy and got some good news today, the first oversize pistons from yamiya are in Chicago, so should make it home any day now.

Any particular tips/advice for properly instructing the machinist?
As for blasting of the cases, should I ask that they only blast the outsides? (I left the counter shaft bearing in there, didn't wan't to bang it out until I have the bearing issues sorted out).
Anything to caution him when blasting the fins on the top end?

MCRider · « **Reply #312 on:** January 30, 2014, 12:34:30 PM »

Quote from: edwardmorris on January 30, 2014, 10:57:57 AM

No luck on finding a shop to widen the grooves on SKF replacements. Worst case, I'll leave the old ones in, or shell out for yamiya ones. Haven't had time to get back to the rotor yet but thanks for the tips Ron and Bill. Been working like crazy and got some good news today, the first oversize pistons from yamiya are in Chicago, so should make it home any day now.

Any particular tips/advice for properly instructing the machinist?
As for blasting of the cases, should I ask that they only blast the outsides? (I left the counter shaft bearing in there, didn't wan't to bang it out until I have the bearing issues sorted out).
Anything to caution him when blasting the fins on the top end?

When I did my cases, plastic beads, not glass, I bolted the 2 case halves together. I think at the time someone had warned me about not blasting the areas where the crank main bearings lie. But even at that, everything had to be removed, ball bearings and such, as the beads get EVERYWHERE. Clean up is a #$%*, though with plastic you have the comfort of knowing if you missed a few they won't tear anything up...much.

No caution on the fins, just don't break any handling it too rough.

BPellerine · « **Reply #313 on:** January 30, 2014, 04:33:09 PM »

you have the desired piston clearance in your hondaman book for your replacement pistons make absolutely sure they understand to stay within those tolerances!!! they should measure each piston to its bore and mark the ie 1,2,3,4 so that you will assemble them in the correct hole.if you have to bring your specs with you and be double sure they understand you.bill

edwardmorris · « **Reply #314 on:** January 30, 2014, 09:11:34 PM »

Thank you Ron and Bill, added to my notes. Will go through the literature and spell it out for the guy as best as I can.

Bits of good news trickling in, got a solid center stand with mounting hardware, ignition switch bracket and a correct K2 oil tank (mine had a K0 tank on it) from Bill/Benton-Racing and Stev-o very generously sent me a great looking shifter drum. Gotta call my welder and get a time to get the center stand lowered. Will take the ruined shifter drum with me in case he can salvage it on a lathe.

HondaMan · « **Reply #315 on:** January 30, 2014, 10:07:34 PM »

Quote from: edwardmorris on January 30, 2014, 09:11:34 PM

Thank you Ron and Bill, added to my notes. Will go through the literature and spell it out for the guy as best as I can.

Bits of good news trickling in, got a solid center stand with mounting hardware, ignition switch bracket and a correct K2 oil tank (mine had a K0 tank on it) from Bill/Benton-Racing and Stev-o very generously sent me a great looking shifter drum. Gotta call my welder and get a time to get the center stand lowered. Will take the ruined shifter drum with me in case he can salvage it on a lathe.

Was that K0 tank useable? I need one for my [very slow] K0 resto I'm attempting. It's rough. (That's kind...).

Make sure the shop knows you want .001" clearance for those pistons. Honda specs it as .0008"-.0012", so they let it have production tolerances of just 2 ten thousandths either way. In my experience, when using Honda's own pistons from ART, they run best at the tighter end of the spectrum.

The best part of all: you'll now have round bores that will last a VERY long time. When I took my .25mm oversize out last Fall for this rebuild, the bores are still round within any measure I can get, at 90k miles on the pistons. Once those sleeves are cured, they are amazing!

Terry in Australia · « **Reply #316 on:** January 31, 2014, 12:15:16 AM »

I think I mentioned it earlier Ed, but you don't have a K0 oil tank, you've got a K2 oil tank that someone had filled the dimples with bondo. Cheers, Terry.

tweakin · « **Reply #317 on:** January 31, 2014, 05:14:39 AM »

Making great progress Ed.

edwardmorris · « **Reply #318 on:** January 31, 2014, 08:38:32 AM »

Quote from: Terry in Australia on January 31, 2014, 12:15:16 AM

I think I mentioned it earlier Ed, but you don't have a K0 oil tank, you've got a K2 oil tank that someone had filled the dimples with bondo. Cheers, Terry.

Damn! did I miss this or completely forget? I'll dig it out and see if bondo is scraping off and put some pix on Sunday (wife mandated that I not work Sundays

). More than one person had pointed out it was the wrong tank so I started looking. The one from bill is in better shape than mine anyway so no harm owning a spare

.

Mark, if it does turn out to be a K0, you can have it.

edwardmorris · « **Reply #319 on:** January 31, 2014, 09:08:27 PM »

Cases, cylinders and head are all ready to go, will drop them off on my way back in the morning. I printed out detailed instructions on clearances, honing and plastic bead blasting on the outsides only.

I'm impressed with Yamiya, this stuff looks great, fast shipping and good packaging. But, that hole in the wallet is undeniable

Pic 3. Gotta run back so no time to look at the books, but this curious set of letters in the lower crankcase, what are they?

Terry in Australia · « **Reply #320 on:** January 31, 2014, 10:15:46 PM »

Looking good Ed, make sure you leave your pistons with the guy doing the rebore so he can match them to the bores.

edwardmorris · « **Reply #321 on:** February 01, 2014, 01:57:59 PM »

Quote from: Terry in Australia on January 31, 2014, 10:15:46 PM

Looking good Ed, make sure you leave your pistons with the guy doing the rebore so he can match them to the bores.

Haha yep. I called him and asked what to bring with after Bill posted earlier and the machinist asked for all four pistons. I asked him why and he told me that he needs to match each to its own bore. Looks like he knows what he's doing so I'm hoping for the best.

I won't be getting anything back until next Saturday because there were nine other (car) heads ahead of me

As expected, he was surprised how tight the clearance is so I handed him a print of notes from Mark and he went "REALLY? I learn something new everyday". I asked him to do mine carefully and separate, not in the "rhythm" of doing several car heads one by one, and he agreed

Snowed in like nuts again so home for the remainder of the weekend. Too many things need attention, not sure what to pick up.....

BPellerine · « **Reply #322 on:** February 01, 2014, 05:25:24 PM »

looks like you are on the way up now Ed now the wait begins!bill

tweakin · « **Reply #323 on:** February 01, 2014, 06:27:55 PM »

Quote from: edwardmorris on January 31, 2014, 09:08:27 PM

Pic 3. Gotta run back so no time to look at the books, but this curious set of letters in the lower crankcase, what are they?

I think the letters in cases are a worker with too much time on there hands... I have damn nearly the alphabet in my 71.

edwardmorris · « **Reply #324 on:** February 01, 2014, 08:04:04 PM »

Quote from: BPellerine on February 01, 2014, 05:25:24 PM

looks like you are on the way up now Ed now the wait begins!bill

Haha, I wish Bill. Still not motivated to touch the electrical stuff, that's not going to be fun, along with the aluminum covers to sand and polish, and no lead on the transmission bearing situation yet. Capitalizing on bad weather to rack up as many work hours as I can, because I KNOW once the start the climb, my finances are going to take a diiiiiiivve.

Tweakin, thanks for the info, I wondered if it was some kinda code like the crank bearings...

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Author Topic: 1972 CB750 Four K2 -- Rebuilt to NEW OLD STOCK -- PIX ON PAGE 50 (Read 241140 times)