Honda CB750K5 Restoration by Royhall

[Johnny4428]

That is getting to the exciting part now Roy! Nice work on the headlight.😜

[royhall]

I was going to get the exhaust system unpacked and fitted, but looking at the bike it would be better to do some of the smaller parts first as the access would be much easier. So firstly I built up the footrests and rear brake mechanism. The footrests required more work than I realised. The main struts were powder coated when the frame was done, all the zinc parts were cleaned and replated, and new rubbers were fitted. They went together quite easily with just the powder coating requiring drilling out for the pins. Right side first went on at the same time as the re-chromed back brake lever, all fitted with new bolts and nuts and a new switch spring.

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The left side went on and after centralising the engine stud the bolts tightened up.

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Next up was the refurbished oil tank. This has been taped up and carefully blasted to remove the old paint then re-painted using two pack gloss black. After painting it was carefully cleaned and checked for any blasting residue. I must have flushed it out at least 6 times. A good look with my borescope revealed that it was totally clean. I was a bit worried about the painter blasting it (I didn't know he was going to do it) due to leftovers getting into the oil. I didn't need to worry as he used rubber bungs on the holes and masked everything else then turned the pressure right down on the blaster. I fitted the second hand hoses that I got from DK as the ones with the bike were frayed and in a right mess. I fitted new aluminium washers and o-rings and tightened everything up. Of course the tank went on with new mounting rubbers and bolts (all these little bits add up to more than you realise).

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I thought next I would have a go at the bit I was dreading, painting the Honda logo on the rear of the seat. I was right to be dreading it as it went very wrong. I got a stencil off PIki which was firmly stuck in place after careful measuring. I then masked off the rest of the seat to prevent overspray. After ensuring all the edges were down I sprayed a first coat of clear to seal the ridges in the cover, followed by three light coats of silver Rustoleum PVC spray. I let it dry for a couple of hours then unmasked it to find this horror.

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I then spent a fun two hours trying to gently clean it up with a new scalpel blade, dragging it like a razor. This only worked to a degree but did improve things quite a bit. Next I ordered some black Rustoleum off Amazon for next day. With this I carefully touched in the nasty bits around the edges, It's not perfect but still good enough to use.

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You can see the black around the logo as it's a bit more reflective than the PVC cover (it looks worse due to camera flash, nothing like that in reality) so I polished the sides of the seat with wax furniture polish and now the shiny bits are blended better. After this fiasco the exhausts will be a welcome easy job.

[Oddjob]

What most people forget Roy is to grease the footrest pins, they then rust and start to oval out the holes. A little bit of foresight can save an awful lot of heartache years down the line.

Same with stuff like the brake pedal pivot pin, they get so excited about starting to put it together they seem to forget to do stuff.

Is the points cover a temporary affair as it seems quite dented, I know the price of these has gone through the roof so I wouldn't be surprised if you've fitted the old one until it's finished to save potential damage etc.

Coming on though Roy, starting to look the part.

[royhall]

Don't worry Ken everything is very well greased. Yes the cover is still the dodgy £3 thing I got off eBay to sit the engine on whilst the frame was lowered over it. Wont be doing stunts like that with a £180 points cover, the real one will be fitted shortly. I now actually have two nearly perfect covers so if anyone is needing one it's yours (at a price of course).

[Oddjob]

Yeah, I'd have done the same thing Roy, not worth risking the new cover.

BTW, mate of mine was trawling round Macclesfield superbike centre the other day and told me that an identical CB1300 to mine was for sale, must still be your old one.

[royhall]

Is that the black half fairing model with the full Acky system. That would be nice, hope they have to discount it to get rid.

[Oddjob]

Actually he said it was the same as mine and mines the naked version. Maybe he meant same colour as mine, red/white.

[Laverda Dave]

It's all getting tantalisingly close to start up Roy. Great rebuild thread👍

[royhall]

Finally time to open the big boxes and get the exhausts fitted. These are pattern parts that came from Colin at Predator Motorsports. Speaking to him on the phone he claims to be the guy that has these made in Japan and then sells them on to Silvers and CMSL, not sure how true that is. Being pattern parts, and considering my experience over the years with pattern parts, I'm not expecting this to go well. This is what was in the boxes.

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They don't look too bad on initial inspection, the welds are slightly saw toothed but that would be nit picking. They had sticky labels indicating 1 to 4 so no problems sorting them out. The clamping rings are also pattern parts as the bike came without an exhaust. The stubs were already fitted earlier. Not much else to say really as surprisingly they fitted straight on. No pushing and pulling, no trying to line up holes or anything, just straight on first time. Everything is straight and lined up. For pattern parts it's a miracle. Well done whoever built them. Some photo's.

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Now I'm getting somewhere. I was expecting a battle with these but am pleasantly surprised.

[royhall]

Just a few little jobs now before the anxious fire up moment. I need to make up some HT leads to fit to the micro coils. I got some fittings from Boyer that I didn't seem to be able to get from anywhere else. A little bit of soldering and another job bites the dust. As the side panels were sat looking at me I decided to get the badges on and fit them. After dry fitting the badges there was a lump preventing it sitting correctly. I should say at this point that foolishly I didn't test fit the pattern side panels before painting. Had they been from Silvers that could have been an issue, but as they came from Yamiya in Japan I think it will be okay. The lump was an injection mould runner so I just carefully took them off with the Dremmel.

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I remember reading about someone fitting the side panel badges the wrong way round. So I checked on the pictures that James H sent me of an untouched K5 and did it correctly. Easy mistake to make if you don't know about it. The Honda feathered logo has the pointy bit forwards. As I don't want to lose them on some back road somewhere I put a couple of dabs of clear silicone behind them then fit the star clips. As I thought, the Yamiya panels fitted perfectly with some new rubbers of course.

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Last job before trying a start up is a tedious chore that I just want out of the way. Wheel alignment. It's time for crawling around on the floor again. It just needs two heavy weights and two lengths of sting. I tied the string to the back wheel as per the photo then round the weight. Same both sides. Then the weight is moved bit by bit until it just touches the the front of the back tyre, again the same at the other side. Then straighten the front wheel and see how even the gaps are, in my case a turn to the right was required. I unlocked the axle nut and using the chain adjusters moved the front of the wheel to the right. Then you have to do the string thing all over again. Like I said, tedious. Keep repeating this until the wheels are aligned, then tighten the axle nut. Don't forget to watch the drive chain tension, then nip up the adjuster bolts and locknuts. And don't forget the split pin through the axle castle nut, MOT failure. Simples.

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[royhall]

I got the number plate fitted in anticipation of a test ride. I know what your thinking, START THE BUGGER ALREADY.    I am very close to start up now so before it burns to the ground, a few pictures of where the project is up to.

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And one just for Ken.

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In the next thrilling issue I promise I will try and start it. Scary moment but can't put it off any longer.

[royhall]

Just a couple more up to date pictures before the big event.

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At this point I removed the spark plugs to make the engine easy to spin over. I filled the oil tank to the top mark with 10W40 semi synthetic. Gave it a good kicking over with the ignition on to fill the filter chamber and oilways. The oil light went out surprisingly quickly. I topped up the oil back to the top mark and fitted new spark plugs. I previously bought some ethanol resistant fuel hose so I made up some slightly longer than usual lengths as I like to fit inline filters. The pipes were held in place with spring clips. I connected my test tank using a Y pipe fitting then discovered that the test tank valve was leaking. Cant stop now so I placed a tray under the tank to catch the drips (I will order a Sealey one later). I turned on the tank to let the carbs fill for the first time and left it a short while, luckily no pools of petrol on the floor, always a good sign.

So fuel on, plugs in, oil galleries full, fully charged battery. Nothing left to do now but get the fire extinguisher ready and press the button. Wish me luck.

Honda CB750K5 initial startup - YouTube

[mickwinf]

Another one comes back to life! well done!

[K2-K6]

Very nice work Roy, and quite a change from when we first saw it.

I really like them in blue too.

[Johnny4428]

Nice one Roy! Sounding good too!👍