Honda CB750K5 Restoration by Royhall

[Oddjob]

Roy is that a spare points cover on the engine? You mentioned it was really bad but the chromer did a good job of mending it and tbh it looks ok in the pic of all the chrome parts but in the engine pic you can clearly see all the denting etc and the chrome looks faded, like it’s really old. Is it the same cover?

[royhall]

No it's not the same cover, like I said it's one I got off eBay for £3 for construction use so it didn't matter if I damaged it whilst the engine was on it's side. It really is pretty badly damaged, too much to be used on a finished bike. The real one is the first picture below. Just a few more pictures to go with the above text.

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If anybody can spot from the photo's anything that has been done wrongly or not quite right please feel free to say so. Would be appreciated, thanks.

[Johnny4428]

Hi Roy, the only thing I see that I don’t think is right is the large washer between frame and rear shock top mounts?

[philward]

Thats looking really good Roy!

[Lobo]

Beautiful Roy - another Honda saved.

Before the rear frame area gets filled in, did you remember to grind away powder coat in the frame - engine area to guarantee a good battery earth? I didn’t 🤦‍♂️! (but then used the forward LH engine mount which tbh makes me happier as easier to keep an eye on / electrically clean)

Your rear sprocket studs appear to be shorter than mine (K2) in that the studs are shy of using the full nut threads. Is this normal for the K5?

Jealous of your chroming - I should have done a bit more, but like you was becoming very wary of the ‘where does it all end’ dilemma.

[royhall]

Thanks for trouble shooting guys, There are a couple of issues to address before I move forwards with it.

Johnny. Your right about the big washer, the parts book shows it as fitted to the other side of the shock. I will address that when I drop the swingarm again to take all the powder coating of the frame around the bushes. The swingarm works just fine as it is but I'm not happy with it.

Lobo. You must have eyes like a shit house rat. I didn't notice the  short of one thread on the nuts when I was assembling it. The problem appears to be the new genuine Honda nuts. They came in four bags with the correct parts number, but when I compared them to the old rusty ones just now they are about one thread thicker. So that's the issue. They can stay like that as all the threads on the studs are used correctly. The other issue you mentioned was an O Fu**ing Hell moment. Yes, I have forgotten the earth strap, and worse I haven't removed the powder coating either. I will see when the swingarm is out if I can open up the frame a little bit so I can get a thin file in there. Failing that, can you post a picture of your fix.

[Laverdaroo]

Roy,
the nuts that came from Mr Silvers for my ear sprocket were short a thread too. They're on and staying like that but I had to do the same and check them against the OE ones that came off it.

Bit odd? they were in sealed factory parts bags also.??

[Lobo]

…interesting how thicker nuts are now supplied; guess accountants involved and using a one-size-fits-all approach?

Wrt the earthing, I genuinely submit that leaving the frame pristine in the original frame-engine earthing area will save you possible corrosion issues down the track - this area is pretty inaccessible once the bike buttoned up. (Of course you will still need to strip the frame of ‘coat immediately under the battery earth strap)

Through necessity (😬) I used a front mount, and as said, am much happier as now I can keep an eye, and better still, easily fettle any bared paint corrosion should it start. The powder coat has been carefully removed under the head of the marked bolt. You can easily guess, I don’t intend to have this bike apart anymore within my life!
(Comment… we ride in different climates; my bike never gets wet and this bolt is obviously more exposed. Otoh, the ‘OEM’ area may be wet at times too I guess.. just less seen!)

[royhall]

Thanks for the feedback, those small issues will be sorted further down the line. In reality I don't have much choice about that as the bike is way ahead of the forum write up, so some reversing will be required. It will get done though as it needs to be right.

Before I turn my attention to the front end I have got some of the back done. As I always do, before fitting the mudguards I sprayed the insides with a liberal dose of cold galvanise spray. I'm not intending to use it in the rain but sometimes you get caught out whilst out on a run so thought I would give them some protection. It can't be easily seen from the outside but looks fairly neat anyway.

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The back mudguard fitted. The chrome looks a really good job even covered in greasy hand marks.

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Turning now to the front end a problem soon became apparent. I had previously bought a set of fork ears from Silvers at just short of a "sack of gold" as mine were badly twisted and dented and more than a little rusty. When test fitting the rubbers gaiters it was clear that the trim ring would not fit. I tried the gaiters on the old ears and it was all perfect so clearly the problem was with the Silvers ears. As usual Silvers disputed this and said they tried all their stock and they were okay but they would accept a return and refund so happy days. These are the pictures of the silvers item and genuine.

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So not wishing to order the same again I thought I would give the Dutch suppliers a miss and order a set from Yamiya. After parting with "two sacks of gold" they arrived. The quality of the Yamiya parts was way above Silvers items and guess what, they fit perfectly. They have added to the bill but at least that problem is now solved.

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[Johnny4428]

Quite annoying! It beats me that when some of these replicas are produced that the manufacturers fail to get dimensions right.😡
Coming along nicely Roy! On target for a spring time road run?😜

[royhall]

I spent a bit of time cleaning the black plastic parts and treating them with plastic polish. Some items came up like brand new so it was well worth the effort. So just another couple of shots of the back end before I move on to the front,

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Onto the front. I fitted new AllBalls taper rollers, after some careful measuring to ensure that the correct thickness spacer washer was used (a bit tricky). The bearing casings went into the freezer overnight to shrink them a bit and they went into place really easily. At this point I discovered a couple of things about the yokes. The powder coating had not been masked correctly (they said they would rather do it than me), and the lower pinch bolts which should be a fine thread had been tapped out at some point in the past to standard threads. So I spent the next two happy hours scraping out powder coating with a scalpel, next time I will do the masking. That done the yokes fitted no problem.

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Next up was to build up the forks. Sorry in the excitement I forgot to take the photo's, but there are before and after shots. I sent the original fork tubes out for hard chroming but they were returned as parts of both tubes had pitting too deep to be repaired. So that meant a set of reproduction tubes, not really my first choice but they look decent quality.

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[royhall]

Finally on the forks I needed to fill with new fork oil. As I don't have an accurate measuring jug for use in the garage I did my usual thing. I use a disposable clear plastic cup and a marker pen. Using the kitchen measuring jug I fill with water to the correct level then tip the water into the cup. After it settles I make a marker pen line aroung the cup them empty out the water leaving the mark at the correct quantity. After drying out the cup with tissue I fill with new fork oil and pour into the fork and fit the top caps. Forks finished.

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Just a shot now of the fork yokes fitted with the Yamiya ears and new seal rings. Note the now non standard bottom pinch bolts.

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[JamesH]

Great progress Roy - feels like you’ve got some real momentum now and she’s looking very nice indeed!

[Trigger]

Put the gators on the ears first as the rings will not move up far enough while mounted to seat the gators 

[royhall]

Tried all ways Trig, they just would not go on. They fit the Yamiya ones and the originals no bother. I think I just got a bad set as Silvers said the others in stock were okay.