Newbie CB750

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Hi, I am new to this forum and am hoping to use it to gather some information and help / advice as yesterday I picked up my new (and first) project bike: A 1983 Honda CB 750 RC 04.

I got the bike cheap in an Ebay Auction although it is in a lot worse condition than I originally thought and is currently a non starter.

I have no current fixed plans for the bike so any inputs are welcome !!! The first step is to try and get the motor started to see what I have to work with Smile

As mentioned, this is my first project and I am a bit of a novice but looking forward to seeing what I can do with the bike !!!

I will update this forum as I make progress with the bike !!!

Attached is the picture taken from the Ebay Ad.

Posted: Mon Feb 06, 2012 1:20 pm

Looks like it missing just a few small pieces and parts...but def looks like it'll be a sweet ride when complete. Just follow these guy's advice, and you'll easily be on your way to winding the piss outta that thing soon!

Welcome to the Carnival of Madness!! beerchug

Posted: Mon Feb 06, 2012 3:58 pm

Hi neighbour welcome to this forum,I could not find the picture but you probebly put one on this site soon Smile

Wim

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

metalganz wrote:

Hi neighbour welcome to this forum,I could not find the picture but you probebly put one on this site soon Smile

Wim

mmm The link did not appear to work using the embed image tabs "[ img ][ /img ]" Sad

Try clicking THIS LINK Smile

Posted: Mon Feb 06, 2012 4:37 pm

Yes that works,looks like a custom frame cb750c.Are you thinking to rebuild it to a streetfighter,or more the original looks?
Wim

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

metalganz wrote:

Yes that works,looks like a custom frame cb750c.Are you thinking to rebuild it to a streetfighter,or more the original looks?
Wim

It is a CB 750 RC04 (if that means anything to you). The tank looks similar to those on the Boldor ??? The frame is not so "custom" just (and unfortunately) hacked off at the back as far as I know

No I dont really want to go for a fighter... I want to try and go down the original / cafe race route ! I quite like the style of the older shape CB with the more rounded tank, so may ditch the current tank / bodywork try to go for something like that. I am currently still debating if I want to go the whole hog and replace / renew the chassis running gear (forks, swingarm, brakes and wheels etc) with some thing a bit more "beefy" and modern Smile

I know this is is a not a CB750 but I like the look of this: CBX1000

I also like this: CB750

I want to try and find a nice balance between the two. E.g. mixing old with new to have a slightly agressive looking classic (if you know what I mean)

Let me know what you think

PS I will have a play with some ideas in PhotoShop before I start and get them posted Smile

Posted: Mon Feb 06, 2012 8:09 pm

I think I know what you mean and it would be my second thought after the original thing.There was some time ago a member also from germany who fabricated aluminium tanks for cafe`s.Personally I like the styling of the 750 most,but look around on the internet there is much to see.
Curious what you make of it,the guys on this forum including me like pics of the bike very much.

Wim

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

metalganz wrote:

I think I know what you mean and it would be my second thought after the original thing.There was some time ago a member also from germany who fabricated aluminium tanks for cafe`s.Personally I like the styling of the 750 most,but look around on the internet there is much to see.
Curious what you make of it,the guys on this forum including me like pics of the bike very much.

Wim

Ok, I will keep you all posted with pics !!! First step though is to get the motor running Smile

Just have to find the courage to go out in the -20 weather

Posted: Mon Feb 06, 2012 9:38 pm

I wouldt do that if I were you,I asked my wife if I could do my restoring in the livingroom Smile

but she

.
Oke buy me an electrical heater for the very cold moments.

Cheers,

Wim

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Its a runner (sort of). After finally getting the correct battery sorted for the bike, I fitted it and after a while of trying get it started Smile

However, there was a not too healthy knocking noise from the engine Sad

The engine is coming out in anycase biut if anyone has an idea re what it is likely to be im interested. It sounds like a "mechanical" knock so im guessing its going to something like primary chain rattling or crankshaft bearings ?

Posted: Sat Feb 18, 2012 4:50 pm

Could be the clutch,also check the carbs and synchronise them.If both are ok and there is still a bad sound then you may have a bigger problem.

Posted: Sat Feb 18, 2012 9:48 pm

metalganz wrote:

Yes that works,looks like a custom frame cb750c.Are you thinking to rebuild it to a streetfighter,or more the original looks?
Wim

It is definitely a F.....the rearset plates give it away.....

You will find what you need here friend...... Wink

Make sure you check out the Technical Documents section.....
and Mike Nixons website..... www.motorcycleproject.com

WELCOME!

Jebby

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Sorry, I have been having a few problems sorting out an image server to link my posts to... I have now sorted it put so will upload a few updates re the project Smile

A couple more pics before I get to work on it:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

The bike had no power Sad

at first I thought it had a flat battery until further investigation proved it had no battery at all :

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

The new battery arrived, so I filled it with acid and let it charge for a few hours before fitting it:

The first (wrong) battery... The Honda garage gave me a "CB14-A2" until I found out it was wrong, so changed it to the correct battery...

The correct "YB14L-A2" fitted to the bike:

After checking the oil and giving it some fresh petrol, it eventually started Smile

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Today I managed to find a bit of time and I started to prepare the engine for removal.
Some progress pics:

Managed to clear a bit of space (althpugh not much Sad

I have too much junk) so I can work arounf the bike a bit easier:

The carb rubbers(both sides) were that old and worn they were solid and had now flex in them at all Sad

therefore I had to remove / move back the Air box and housing to give me more room to maneuver the carbs and have any chance of getting them out. To enable me to move the air box housing back I had to firstly remove the Battery casing:

Battery casing out:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Onto the Carburetors:

Removing the Throttle / Choke cables:

and out

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Time to remove the scratty old Exhaust:

Tacho cable:

HT leads:

Front sprocket:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

The motor is now pretty much ready for removal (i hope) its all free of components and cables connecting it to the rast of the bike. I just need to drain the engine oil and somehow get this nut undone:

I cant for the life of me undo it - its solid... I will try and get a nice long(er) breaker bar and give it another shot. If anyone has any ideas re how to get it off, I would appreciate any advice Smile

(its the big swingarm nut)

Posted: Mon Feb 20, 2012 11:52 am

Maybe with air pressure?What code is on the carbs,I did see VR I think?

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

metalganz wrote:

Maybe with air pressure?What code is on the carbs,I did see VR I think?

Yes VR is on the side of the carbs.

Posted: Mon Feb 20, 2012 12:45 pm

To get the engine mounting bolt undone, you are probably best to soak it in penetrating oil, both sides, and use a hex sided socket each side - one that engages on the flats of the nuts, not the 12-sided sockets that engage on the edges of the nut. I found this out the hard way on a GSX750F....broke the socket.

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Dearnla wrote:

To get the engine mounting bolt undone, you are probably best to soak it in penetrating oil, both sides, and use a hex sided socket each side - one that engages on the flats of the nuts, not the 12-sided sockets that engage on the edges of the nut. I found this out the hard way on a GSX750F....broke the socket.

Hi, thanks for the tip !!! I did just that I soaked the bolt with WD40 and got a extended breaker bar of both sides and with a little effort and some help from a friend it came off Smile

Thanks again !!!

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

After another day spent in the garage I managed to get some more progress done (i cant wait for the clocks to change and the weather to get better, so I can get some hours in after work during the week).

My mate T came round to help me get the motor out, but first we had to finish a few bits off to prepare the motor for removal:

This is the bolt I have been having a few issues with re getting it off:

We eventually got it off (after some effort and an additional trip to the DIY store)

Jack in place to take some of the engine weight:

Started to remove the engine bolts:

And frame mountain bracket bolts:

Ready to be lifted out:

Out

Cheers T

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Next onto stripping the rest of the bike:

First off, the wheels, front wheel:

and the back wheel:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Backend / Swing arm removal:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

I hate electrics....

This will be replaced by a nice round headlight if all goes to plan Smile

Toll the front brakes off while stripping the electrics:

Finally the loom is out:

Twinstar Joined: Feb 06, 2012 Posts: 169 Location: Germany

Dismantling the front end:

Garage could pb do with another tidy up at this stage...

Just need to take the yokes off now but need to buy a bigger socket Sad

Posted: Mon Feb 27, 2012 9:45 pm

at least it had oil in it to drain even if it was a little dark.

Posted: Fri Mar 02, 2012 5:32 pm

Hey there,

Fascinating project, newbie. Photos are very interesting! As a perpetual newbie, I can't imagine tackling this project myself, but seeing your electrical harness and all the wiring makes me think about replacing the harness on my bike in 2004 with the help of my mate Matt. He was a wonderful mechanic and usually did it all but he made me get my hands dirty with this work and I'm glad I did. I wish I would have spent more time mucking around with him on the bike. Now I've got the need and the interest and no money, so I try to help more where I can. Here's to women riding CBs !

Hope to read/see that first ride on your CB one day soon here.

Cheers,
Glenda@PSB MT