Topic: 1978 CB750 K8 project

[calj737]

hard to tell from the picture, but do you think a quality porting job might not be able to smooth it out?

[martin_uk]

I might try grinding to depth of pits, but exhaust sealing ring face will need attention.

[martin_uk]

Picked up tank, petrol flap and side covers today

Images dont fully show how good the colour is, as it really sparkles.

2015_0312tank0006 by nitram2010, on Flickr

2015_0312tank0001 by nitram2010, on Flickr

2015_0312tank0004 by nitram2010, on Flickr

2015_0312tank0007 by nitram2010, on Flickr

[Restoration Fan]

Beautiful.  What color is that called?  It doesn't look like one of the standard Honda reds from the photo.

[SOHC4 Cafe Racer Fan]

Beautiful.  What color is that called?  It doesn't look like one of the standard Honda reds from the photo.

Well, it definitely does not look a standard US color or a standard Euro color either.  That said, it really pops! Nice choice.

[martin_uk]

Beautiful.  What color is that called?  It doesn't look like one of the standard Honda reds from the photo.

Its a Renault car colour, saw it on a car and thought it would look good on a bike.

The original was a bit drab.
2014_1206Kparts20094 by nitram2010, on Flickr

Bit of an improvement.
2014_1206Kparts0034 by nitram2010, on Flickr

Its used on latest Renault Clio in Europe and is a 3 stage pearl finish.

Now have to decide whether to apply original decals.

[martin_uk]

Its called Ultra Red

http://pistonmad.com/wp-content/uploads/2014/11/Renault-Clio-1024x682.jpg

[martin_uk]

The bike did not come with side panels and I have bought replica ones.

Still not sure whether it would have had badges like this

Shown on DSS https://www.davidsilverspares.co.uk/graphics/parts/87123405000P_large.jpg



or this https://www.davidsilverspares.co.uk/graphics/parts/87127392000P_large.jpg



Have seen images with seperate K decal and gold line

http://s515.photobucket.com/user/DVanZuiden/media/1978%20CB750K/CB750K%20Finished%20Pictures%2010-18-09/IMG_0827.jpg.html

[SOHC4 Cafe Racer Fan]

The top badge is for a 77 CB750K7

[kap384@telus.net]

Yup, the lower one is just for the 'F's

[hondamad]

Just as it should be done excellent

[SOHC4 Cafe Racer Fan]

It is my understanding that the 1978 CB750K8 emblem is the one pictured on the bike (above) and that the capital "F" does not extend underneath the CB750 our text - only above - with the line and K further underneath.

http://honda750expert.com/

[martin_uk]

Finished the part assembly of engine and ready to fit.

2015_0321eng0015 by nitram2010, on Flickr

2015_0321eng0014 by nitram2010, on Flickr

Frame prepped with pipe insulation and plastic waste pipe split and fitted to right bottom rail to protect

2015_0321eng0016 by nitram2010, on Flickr

Engine went in OK with help of friend on other end of lifting bar, but seem to have lost images

[martin_uk]

I bought a K7 brake master cylinder and new genuine stop switch, but no provision for fitting 

Decided to go with replica DSS unit and banjo bolt switch from China, with made up wiring loom.

2015_0321eng0004 by nitram2010, on Flickr

Seems to work OK

[seanbarney41]

I would probably smooth it out a little by hand or a sanding roll and run it.  Only concern is where the damage intrudes into the boss for the copper gasket but it looks to me like it might be ok?  Doubt anyone is gonna notice any performance difference.   High temp epoxy/jb weld is an option too...  If it ends up in your muffler?...none the wiser

[madmtnmotors]

The 78 badge is more Roman Numeral-esque and is unique to the 78 AFAIK:





And I have found them here (little pricey though):

http://www.marblesmotors.com/partsforsalehondabadges.htm

[martin_uk]

The 78 badge is more Roman Numeral-esque and is unique to the 78 AFAIK:





And I have found them here (little pricey though):

http://www.marblesmotors.com/partsforsalehondabadges.htm

Thanks for that, sounds like they will be ultra rare/expensive, so will put on hold for moment

[martin_uk]

Made quite a bit of progress, but seem to have problem importing images from my camera.

Engine fitted up apart from carbs, as just realised the K7/8 had differentent rubber mounts which are on back order

Clutch assembly slightly caught me out as the rear ally plate with the spring pillars had not engaged in outer splines.

So if you find spring bolts seem too short to engage with pillars, may be the problem.

I stripped oil pump and found rotor lobe damage so swapped with a good used one.

Put in engine oil, initial  3 ltrs of running in oil, which should help the rings bed in.

Tried spinning up engine  with plugs out, but no drop in oil level and oil light still on.

Dont like starting without pressure present, but having  prlmed pump, may have to, athough may try pressuring oil tank via beather pipe,  which worked on last bike.

[Restoration Fan]

Martin,
Have you thought about just putting an oil pressure gauge on and confirming oil pressure before you try starting it?

Ron

[martin_uk]

Martin,
Have you thought about just putting an oil pressure gauge on and confirming oil pressure before you try starting it?

Ron

I have had a look  at a few pressure gauges and considering for my cafe racer. how did you adapt the oil gallery plug?

To fully prime, I used a car tubeless tyre valve with end cut off and fitted into end of tube same size as breather tube on oil tank  clamped with Jubilee clip.

After pressurising and a few spins of engine the oil light went out.

Removed pressure and oil light goes out each time engine spun

[Restoration Fan]

I have had a look  at a few pressure gauges and considering for my cafe racer. how did you adapt the oil gallery plug?

To fully prime, I used a car tubeless tyre valve with end cut off and fitted into end of tube same size as breather tube on oil tank  clamped with Jubilee clip.

After pressurising and a few spins of engine the oil light went out.

Removed pressure and oil light goes out each time engine spun

Glad to hear it's going!
As for how I did it, I took the easy way:  I asked Bill Benton one time what kind of oil pressure gauge he uses because I wanted to get one for Stella.  The next time I went to see him, he had purchased one for me and all I had to do was remove the oil galley plug and screw this one in.

[martin_uk]

I fitted a Motad 4 into 1 as I am short of one original no1 HM405 exhaust.

Carb insulators arrived today from DSS, so fitted carbs and thought I would see if the engine runs,

After a few turns it fired up and sounds good 


Have not fitted air cleaner or adjusted carbs but nice to have running.

2015_0407eng0008 by nitram2010, on Flickr

2015_0407eng0009 by nitram2010, on Flickr

2015_0407eng0010 by nitram2010, on Flickr

[martin_uk]

Decided against SS Motad system as mountings wrong, so will use on F1 project.

Decided to fit a used chrome Marshall system I bought and looks and fits much nicer, with more access to oil filter.

2015_0418eng0032 by nitram2010, on Flickr

2015_0418eng0007 by nitram2010, on Flickr

2015_0418eng0009 by nitram2010, on Flickr

The stand stop.

2015_0418eng0010 by nitram2010, on Flickr

2015_0418eng0029 by nitram2010, on Flickr

[martin_uk]

Not too much to do now, but cant easily get the correct length throttle cables in UK and have it booked in for test on Friday, to enable me to register here.

Have used shortest route, with cables I have but may be a problem with tanks fitted.

2015_0418eng0019 by nitram2010, on Flickr


2015_0418eng0018 by nitram2010, on Flickr

2015_0418eng0016 by nitram2010, on Flickr

2015_0418eng0017 by nitram2010, on Flickr

[martin_uk]

My oil gallery cap was damaged and originals are quite expensive, so tried this ally sump plug (Subaru aftermarket) which has a built in magnet to catch stray metal particals.

Used a dowty washer to seal.

2015_0418eng0022 by nitram2010, on Flickr