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46

CB750 / Re: CB750K7/8 PD carb accelerator jets

« on: May 04, 2021, 01:52:57 PM »

I managed to clear obstruction without removing by using carb cleaner and compressed air.

Changed main jets to 110 from 125 and one 0.4mm washer under needle clip.

Now runs fine

47

Misc / Open / Re: Plastic Coated Frame

« on: April 26, 2021, 01:51:56 PM »

I had a Norton Commando that PO had frame plastic coated.

Sounds like a good idea, but started to seperate and water got in between.

48

CB750 / CB750F1 Wiring loom problems and ignition switch

« on: April 24, 2021, 10:52:13 AM »

Just finishing off my last F1 and had bought a new repro wiring loom from DS and a repro ignition switch.

I had to use one of the US spec position wires (Orange/White) to feed switched live to Black in headlamp bowls.

Tail light and pilot would not work although tail did come on in park position on key.

Wiring diagram shows 2 brown wires join by ignition switch but mine did not have a connection in loom, so put in a jumper wire.

Still a problem with tail coming on with handle bar switch.

Fitted an old ignition switch and works fine inc pilot light.

I assume some of the repro ignition switches do not have internal connection required so something to look out for.

49

CB750 / CB750K7/8 PD carb accelerator jets

« on: March 31, 2021, 08:57:49 AM »

I am having a problem cleaning passages without removing the plugs fitted to drilling for accelerator pump jets

I have read about removing the small plugs with pliers, but on mine they are flush with surface so nothing to grip and not sure about putting pressure on jet to try to push down and force plug out.

I have considered drilling out, but then would need to get some made up, unless they are available?.

I have also considered drilling out then tapping hole so that a screw with seal could be fitted, apart from the entry one on carb 2 with pump.

Has anyone found an easy solution?

Are new jets available?

Thanks guys

50

CB750 / CB750F1 Wiring

« on: June 15, 2019, 10:48:42 AM »

Finishing my final F1 project and trying to sort out wiring.

I bought a repro wiring loom from DSS, but having trouble finding the correct wiring diagram.

Its a UK bike reg in Feb 78, but suspect earlier manufacture, as I heard sales dropped off, delaying registrations.

It has a frame number CB750F-10406xx (x to hide)

The wiring diagrams I have all show the horn switch providing an earth to horns with a switched live feed to them .

My switch supplies a live feed to horns which have a permanent earth.

51

CB750 / CB750 SOHC K Crankcase engine number to model

« on: June 15, 2019, 10:36:29 AM »

One of the F1 projects I bought came with an earlier engine.

The number is CB750E-22653xx (x to hide)

I suspect it is a 73 K3, has smaller crank case vent pipe and chain oil feed, but would appreciate confirmation from more knowledgeable K experts.

Thanks

52

CB750 / Re: CB750 F1 Rear indicator mounting plates

« on: June 15, 2019, 10:28:31 AM »

Ended upordering from CMS but one was wrong as bigger.

Managed to repair/refurb one old one.

Now find new Stanley lamps wont fit fully into stems

53

CB750 / CB750 F1 Rear indicator mounting plates

« on: May 15, 2019, 04:04:23 PM »

Has anyone come up with an alternative to the plates with the earthing wires on F1 that mount on to the rear rail on the elongated slot?

I have the rubbers with two holes, but not the plates.

54

CB750 / Re: CB750F1 Rocker deterioration on cam contact pad- Replacement A arm

« on: April 27, 2019, 09:51:40 PM »

Hi Trigger
That is very kind of you and will allow more progress.
I have sent PM

55

CB750 / Re: Just fired up my us k8

« on: April 27, 2019, 03:03:07 PM »

I have a K8 too and have finally collected a full set of original exhausts so now have to fit

56

CB750 / CB750F1 Rocker deterioration on cam contact pad- Replacement A arm

« on: April 27, 2019, 02:55:09 PM »

Still working on my fourth CB750 restoration and have come to the point of assembling the camshaft rocker gear.

Going through the rockers, many have the hardening cracking off at edge.

I dont want to fit in that condition.

I have enough B arms and some extra but only 3 good A arms

The pn is 14431 300 030

Does anyone have a good spare A arm, can swap for a good B arm or may have something you are looking for, as have built up quite a few extra parts from buying various job lots.

Alternatively if you have one for sale.

It does seem odd that my A arms have started to chip, interested in others experience.

57

CB750 / Re: Complete engine gasket set suppliers?

« on: March 28, 2019, 03:56:52 PM »

Thanks for the suggestions guys

58

CB750 / Complete engine gasket set suppliers?

« on: March 27, 2019, 05:50:33 PM »

Working on my fourth and final CB750 SOHC and need an engine gasket kit preferably with the cylinder stud packers/seals.

Previously bought from Cruisin Image, but prices seem to have gone up alot.

Vesra ref is VG-157 and hoping to find a set at sub £50 delivered

Any suggestions

59

CB750 / Re: CB750F1 Valve guide reaming

« on: December 19, 2018, 08:47:12 PM »

Quote from: Trigger on December 10, 2018, 07:52:42 AM

Quote from: martin_uk on December 09, 2018, 04:07:32 PM
Life is a continual learning experience and I have wasted far more money

I spoke to engineering co suggested in Wallington and they can diamond hone for about £30, but it means getting it to and from them.

I have bought an adjustable reamer from UK so will see how that goes.

You will still have to visit a machine shop as, the seat angle needs to match the new guide