Author Topic: Honda CB750K5 Restoration by Royhall  (Read 29715 times)

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #300 on: September 24, 2023, 05:25:29 PM »
Thanks guys. Now the thing is running I need to get on with the list of set up and checking jobs as below.

1. Check fluid levels, and check for oil leaks.
2. Check oil is supplying to both sides of the cylinder head.
3. Check oil is returning to the tank.
4. Check tachometer is working.
5. Check that the battery is charging.
6. Check that the battery is not over charging.
7. Strobe the ignition timing.
8. Vacuum balance the carbs.
9. Fit the petrol tank and seat.

Couldn't do the above before as the test tank was leaking badly, a huge garage fire is probably not the best plan. ;D  So once the engine was started I removed it and emptied the petrol out and put it in the bin. The new Sealey tank has arrived today so the next opportunity I have I can get on with the list. The new tank looks to be a much better quality item than my old one. That said, the old one has done 9 years of service so not too bad. On the plus side the new one has the valve at the end of the pipe, the other was on the tank so every time it was disconnected I had to catch a tube full of petrol. Not ideal.

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Whilst waiting for the new test tank to arrive I got the petrol tank built up. Fitted a new filler cap and found that the pins are now located with circlips. Last time I did one I had to peen the ends over with my chain splitter. Much easier with the circlips.


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The clips that hold the bottom trims are a bit tricky. I wish I had opened them up before the tank was painted. Being very gentle I managed to tease them open without any paint pinging off or cracking. I was a bit concerned that the trims would not sit flush to the tank, but once the tabs were closed over them it pushed them hard against the tank side. I used a small block of soft wood and a small hammer to close the tabs. The trims actually look very good. I temporarily fitted the fuel tap to draw around it, then used a sharp scalpel to remove the paint from under the tap as left on the petrol tends to get under the paint and create blisters. Last job I drilled the paint out of the tank badge locating holes and fitted some new collets. The badges then went on with a couple of dabs of clear silicone. They were gently knocked home using the same block of wood and hammer.

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Just a little fun item that came off eBay, approximately the year the bike was born. All the proceeds (£5) were donated to a hospice, so a worthwhile thing.

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« Last Edit: September 24, 2023, 06:12:57 PM by royhall »
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline philward

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Re: Honda CB750K5 Restoration by Royhall
« Reply #301 on: September 24, 2023, 05:45:30 PM »
Well done Roy, great build and end result
Current Bikes:-
Honda CB750K2 (1975)
Honda CB500K2 (12/1972)
Honda CR750 Replica (1972)
Honda CB350K0 (1969)
Kawasaki ZZR1100D3 (1995)
Kawasaki ZZR250 (1990) Project (Going on eBay ASAP)

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #302 on: September 24, 2023, 06:06:41 PM »
Remember this tank from about 18 months ago? It's the same one, miraculous recovery. To be honest at the start I was going to bin it and buy a very expensive Yamiya set.

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Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline JamesH

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Honda CB750K5 Restoration by Royhall
« Reply #303 on: September 24, 2023, 06:09:47 PM »
Yes Roy! Congratulations. She’s looking and sounding superb. You must be well chuffed. Top effort

Remind me - who prep’d and painted the tank and side covers. They do look superb.

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #304 on: September 24, 2023, 06:19:28 PM »
Thanks James. It was a guy on my local trading estate called Alex. One man paint shop called "Thornton Paints". He's done most of my painting, very good but slow. He did all the blue stuff and a lot of the gloss black. He does them as fill in jobs so it's slow, like a full year slow. But that said, I supplied the decals off Piki and the paint from RS and he did all the work including fitting the decals and charged me £400. Result.
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline Moorey

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Re: Honda CB750K5 Restoration by Royhall
« Reply #305 on: September 24, 2023, 09:15:27 PM »
 
   Well done with sticking with it Roy, that one would have been easy to abandon in the early days. 

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #306 on: September 25, 2023, 03:12:25 PM »
Here's a little quiz for you. I have done a lot of work on the petrol tank for the K5 and it's not been test fitted since it came off the bike 20 months ago. After all the work I still had not noticed the problem with it. Looking at the pictures I posted yesterday the problem suddenly hit me. I am really surprised that you eagle eyed lot have never mentioned it. Can you spot the problem with the tank, answers on a postcard please.
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline JamesH

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Re: Honda CB750K5 Restoration by Royhall
« Reply #307 on: September 25, 2023, 03:22:22 PM »
Here's a little quiz for you. I have done a lot of work on the petrol tank for the K5 and it's not been test fitted since it came off the bike 20 months ago. After all the work I still had not noticed the problem with it. Looking at the pictures I posted yesterday the problem suddenly hit me. I am really surprised that you eagle eyed lot have never mentioned it. Can you spot the problem with the tank, answers on a postcard please.

The fuel tap's on the wrong side for a K5?

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #308 on: September 25, 2023, 03:27:07 PM »
Nice one James got it in one. In all this time I haven't noticed that it's an earlier tank. It's still getting fitted though, if it does fit.
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline JamesH

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Re: Honda CB750K5 Restoration by Royhall
« Reply #309 on: September 25, 2023, 03:30:43 PM »
I assumed you knew and weren't worried about it Roy. Wouldn't bother me either. Just a case of running two fuel lines to the two carb T pieces instead of the single line/additional t-piece setup on the LH K5 petcock arrangement.

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #310 on: September 25, 2023, 05:12:55 PM »
Yep. It doesn't bother me at all. I left the fuel lines extra long to be cut when the tank was on so they will easily reach. Strange though how I did all that work to the tank and never noticed. I knew the tap should be on the left as I have run the pipes to that side. Weird.
« Last Edit: September 25, 2023, 05:14:39 PM by royhall »
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #311 on: September 27, 2023, 02:02:10 PM »
Had a go at the above list to get things running correctly. Checked the oil level and took off the two end tappet caps. I can see oil coming out from both ends of the cam, but not the deluge I was expecting. I think it is correct though. The oil in the tank is warm and slightly frothy so it must be returning from the engine. Whilst the engine was warmed up I strobed the Boyer ignition. I had to make a small adjustment to the magnetic rotor to get it right, but it now strobed okay and running smoother than before. I vacuum checked the carbs and they were a bit out. After adjustments it read correctly at tick over and higher up the revs. so all good. It didn't appear to make any difference to the running though. To be honest the engine is mechanically quiet unlike my 750F2, that's a bag of spanners.

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So all is good then. Well no not really. A couple of problems have shown up for next weekends project. It's not charging the battery. Probably a cable connection I missed somewhere hopefully. And it has a slight misfire on cylinder 1. Good thing about the mini coils is you can unplug the HT lead from the coil, so I shall swap 1 and 4 at the coil and see if the misfire moves to cylinder 4. If not, then I will change the spark plug and possibly HT lead and see what happens. I think it's most likely to be electrical but you never know. I may also check that the tappets haven't closed up. After that I will be stumped. Got the battery back on the optimiser ready for the weekends mission.

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I may be back at weekend looking for idea's. Cheers.
« Last Edit: September 27, 2023, 02:08:42 PM by royhall »
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline Oddjob

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Re: Honda CB750K5 Restoration by Royhall
« Reply #312 on: September 27, 2023, 03:10:05 PM »
Look like the same vac gauges as mine. Switchgear new? if not that's a good restore.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Matt_Harrington

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Re: Honda CB750K5 Restoration by Royhall
« Reply #313 on: September 27, 2023, 03:57:16 PM »
Is the brake master clamp meant to be upside down? (sorry, couldn't resist!)
Matt
___________________________________
CB400F 1976 -  Almost finished
CB400F 1977 - On the road!
Moto Guzzi Le Mans 2 - 1981 (undergoing a spruce up)
CD175 - To be restored
Triumph Speed 400

Offline royhall

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Re: Honda CB750K5 Restoration by Royhall
« Reply #314 on: September 27, 2023, 04:52:21 PM »
Well spotted. I will turn yon bugger over. Ta.
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

 

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