Topic: 1975 CB750 K5 cafe build - first bike, first build - almost there!

[the architect]

it's all about details, isn't it.  i can't wait to see the finished product!!!!

It really is!  And the details can take soooo loooonnnng!

do you know if your gauge mount will fit a 73 500-4???

kfratz3 --  Off-hand, I don't know whether it will fit.  If you can take a couple of measurements for me, I can check it against the 750's dimensions.  I'll need the distance between the gauge bracket mounting tabs on the top triple clamp and the distance between the mounting screws on the underside of one of the gauges (tach and speedo should be the same).

[earner99]

Your build is looking really good.  Do I just need to PM you to get on the list for that cool bracket.

[the architect]

Your build is looking really good.  Do I just need to PM you to get on the list for that cool bracket.

No need to get on a list, now.  I have plenty of brackets cut and ready to send out.  Painted mild steel, painted stainless, brushed stainless, polished stainless -- whatever you want.  They come with all the mounting hardware needed, ready to bolt on. 

Since they don't permanantly or irreversibly alter the bike, I think it's a great way to get a new look from our trusty machines while retaining the ability to go back to stock whenever you might need to.

Send me an email and I'd be glad to get one packed up for you:  modern.built@gmail.com

--chris

[brett_bike]

+1 on the fit to a '73 500Four.  She's coming together nice.

[traveler]

bike looks fantastic!

~Joe

[the architect]

+1 on the fit to a '73 500Four.  She's coming together nice.

brett_bike -- Can you get some measurements of your top triple clamp?  Same ones I mentioned above:  the distance between the gauge bracket mounting tabs on the top triple clamp and the distance between the mounting screws on the underside of one of the gauges (tach and speedo should be the same).  I suspect it will work, but I want to check it against hard numbers, first.  Alternatively, you can buy one and try it out.  If it doesn't work out, I'll refund you.



My wiring is 99% done.  I say 99% because I'm waiting to wrap everything until I make sure the bike starts and runs correctly.  I'd hate to wrap all my wiring, only to discover I need to re-do some connection that's now burried and impossible to locate.

Over the weekend and last night, I managed to put fluid in the brake system and bleed it -- seems to work great, so far.  It stops confidently from walking speed in the garage    Carbs are clean and 90% rebuilt.  Fork oil is in.

But I did run into a self-inflicted setback.  When I built the oil tank, I aparently didn't leave enough room below it to attach the factory oil fittings I'd planned on using.  D'OH!!     Now what?  I'm planning to remake the tank out of aluminum, shortly, but I really wanted the bike ready to ride to an auto-enthusiast get-together this Saturday. 

Is it possible to either 1) get 90 degree elbow replacement fittings that are the same thread as the factory tank oil fittings (thus, hopefully fitting in the small area I have available, or   2) somehow mechanically retrofit new oil fittings (like an oil bulkhead fitting or something) that are in good locations and cap off the ones I've welded on?  I'd look at either of these as temporary, since I'm going to make a new tank, anyway. 

Suggestions???     I could use as many ideas as possible. 

[the architect]

A visual:

[the architect]

Still working, but OH SO CLOSE!  I got to drive her around the neighborhood a bit over the weekend.  I'm in the process of making a new (aluminum   ) oil tank.

I'll post some new process photos, soon, but in the meantime, here's a video of this weekend's start-up.  And, um, er, don't pay any attention to the fact that my oil tank is just shimmed up inside the right side of the frame  

[Laminar]

+1 on the fit to a '73 500Four.  She's coming together nice.

brett_bike -- Can you get some measurements of your top triple clamp?  Same ones I mentioned above:  the distance between the gauge bracket mounting tabs on the top triple clamp and the distance between the mounting screws on the underside of one of the gauges (tach and speedo should be the same).  I suspect it will work, but I want to check it against hard numbers, first.  Alternatively, you can buy one and try it out.  If it doesn't work out, I'll refund you.

The '76 CB550 gauge bracket mounts to the triple trees with bolts spaced 80mm apart on center, and each gauge's mounting screws are 44mm apart on center.

[the architect]

+1 on the fit to a '73 500Four.  She's coming together nice.

brett_bike -- Can you get some measurements of your top triple clamp?  Same ones I mentioned above:  the distance between the gauge bracket mounting tabs on the top triple clamp and the distance between the mounting screws on the underside of one of the gauges (tach and speedo should be the same).  I suspect it will work, but I want to check it against hard numbers, first.  Alternatively, you can buy one and try it out.  If it doesn't work out, I'll refund you.

The '76 CB550 gauge bracket mounts to the triple trees with bolts space 80mm apart on center, and each gauge's mounting screws are 44mm apart on center.

Laminar!  Thank you!    When comparing those measurements to the brackets I designed for my 750 . . . . . it's the same    So, good news CB550 guys -- these will work for you too.

I know the 750 changed its gauges (and its mounting dimensions) in '77 -- i.e. indicator lights mounted between the gauges instead of the handlebar clamp panel.   Does anyone know if the 550 followed suite?  From a brief Google search, the pictures seem to indicate a change.

[the architect]

Build progress update.



Battery / electrics tray is painted and fitted.  Notice the square of paint left out to reveal the bare metal.  The new solid state rectifier will mount here.  I'll spread thermal compound between the rectifier and the tray before putting a bolt through it.  The whole tray will act as its heat sink.





Starting to fit the coponents:  rectifier is in (left side), starter solenoind (center) and key ignition switch (right).  You can also see my main ground cable at the bottom of the image.  I used small rubber bumpers to help isolate the battery from vibration.  These same things are used on the underside of the tray's mounting lip to further help reduce vibration to the electronics.





Aaaahhhhh . . . .  enjoying some sunlight.  Not running yet, but at least getting to feel the light of day.  The wiring is fully installed, here.  The only thing missing is the carbs.





After some careful (and not so careful) cutting and bending, my license plate bracket is on. 

I experienced a catastrophic work bench collapse while working on that bracket -- I guess I shouldn't have been standing on my work bench (which is made of two sheets of plywood sitting on two plastic saw horses) hammering on steel with my mini-sledge.  It was a wild ride all the way to the floor.  I won't do that again . . . .  or will I?





Carbs disassembled for cleaning and rebuilding.  They'll get a 3-hour soak in carb cleaner followed by full rebuild kits.  New seals and gaskets -- yummy!





A neat work area is a happy work area.





That wasn't so bad.  Let's hope they run.  For anyone who's actually still reading this and is thinking about rebuilding their carbs, I highly recommend following the procedure found here:  http://www.salocal.com/sohc/tech/carb/carb.htm  It got me through this with having almost no previous carburetor experience.  And now I know just enough to be dangerous.





I rejuvinated the original (and hard as rocks) rubber carb boots.  They were boiled in 1/2 gallon of water and 4 oz. of wintergreen oil.  Thirty minutes later, soft and pliable.  The downside:  now they smell like Pepto Bismol.  I can't wait 'til they smell like gasoline again.





Carb boots on the bike.  Pliable again, they went on easy with just a squirt of silicone spray.





Carbs: meet bike.  Bike: meet carbs.  Reunited and it feels so good.

Still smells like mint, though.

[Little_Horse]

when's this beast going to get fired up with those newly cleaned carbs?

[traveler]

bike really looks good.

I hope you are keeping this 750...after doing all this work.

Some K0 tank emblems would look perfect on that tank....just the emblems, not the stripe.  Double sided tape could make it happen!


~Joe

[the architect]

when's this beast going to get fired up with those newly cleaned carbs?

I actually fired her up a couple of weeks ago.  Even though my first oil tank wouldn't fit right, I figured out how to just shim it between the side frame bars.  I wanted to make sure oil was flowing both directions.  And I was impatient to hear the engine.    With no mufflers, it's loud    Luckily, one of my neighbors is 90 years old and can't hear a darn thing, and my other neighbor has a Harley, so he can take it.

bike really looks good.

I hope you are keeping this 750...after doing all this work.

Some K0 tank emblems would look perfect on that tank....just the emblems, not the stripe.  Double sided tape could make it happen!


~Joe

Joe --  I've been thinking about smoe sort of signage/branding on the bike.  I do like the K0 emblems.  I'd thought about having some custom vinyl cut (possibly the old school Honda wings, like in your avatar).  Then I can put them on, take them off, change them around however often I like.  The jury is still out, though.

I'll definitely keep the bike for a while and enjoy the ride.  I already want to do another build, so the g.f. tells me I should sell this one and buy 2 more to build.  Very tempting.  I really want to do a CB/CL350.  After the 750, I'll probably be spoiled with its power and capabilities, though. 

[Little_Horse]

is this your first build? Because if it is I would say it needs to stay no matter what, there is something special IMO about the first  .

[Holdingfast]

Man, I gotta say, this is the nicest bike ever. Congrats! You surely are and can be super proud! I'm almost sad that you're almost done with it. I hope you come upon a second project soon, hahaha.

[traveler]

You're not going to be happy with the power deficit if you go to a 350 twin.

~Joe

[earner99]

Build looks great, I love the brackets you made, very high quality.  That bike looks like it is ready for sunshine and open roads.

[logana]

Hello Architech,
Love the bike! Amazing work for a first timer! I am about to start rewiring my 1973 CB750, and was ondering where you sourced the rectifier for your bike? I looked all through your posts and didn't see it! Anyhow, keep up the good work and I hope my bike comes out as nices as yours!

[the architect]

Hello Architech,
Love the bike! Amazing work for a first timer! I am about to start rewiring my 1973 CB750, and was ondering where you sourced the rectifier for your bike? I looked all through your posts and didn't see it! Anyhow, keep up the good work and I hope my bike comes out as nices as yours!

Here you go, my friend:

http://parts.digikey.com/1/parts/432147-rect-bridge-3-pha-800v-35a-d-63-36mt80.html

$15 is steep, compared to the Radio Shack 2-phase rectifiers that are only $3 each.  But it was worth it to only have a single rectifier for all 3 phases.  It's worked great so far, too.  Compared to the original selenium rectifier, the size is hard to beat!



Thanks for all the comments, guys.  It's given me a good bit to think about.  Being my first build, I'm sure I'd regret parting with it.  But, in order to fund my next couple of builds (and pick up a new welder, if I'm really lucky  ), it would be an asset.  I'll think it over a good while before I do anything.  And in the meantime, I'll ride and enjoy it.

You're not going to be happy with the power deficit if you go to a 350 twin.

~Joe

No doubt the 350 would pale in comparison on power.  I just love the idea of some small little "city bike", if you will.  Plus it would be easier to get the g.f. interested in learning ro ride.  I think the size and weight of the 750 intimidates her.  I think a smaller bike (I've even checked out CB175's and 200's) would just be a second, supplementary bike, not my primary ride.  And I could just pick it up and hang it on the wall when I need it out of the way 

[Zaipai]

Love the direction of this build. The brackets are awesome!

Great work!

.: Scott :.

[articblue]

Did you put a heat sink on the reg/rectifier? I saw a bare piece of metal where the reg/rectifier went in the electronics/battery pan..didn't know if that was it.
Just something to keep in mind.

Hello Architech,
Love the bike! Amazing work for a first timer! I am about to start rewiring my 1973 CB750, and was ondering where you sourced the rectifier for your bike? I looked all through your posts and didn't see it! Anyhow, keep up the good work and I hope my bike comes out as nices as yours!

Here you go, my friend:

http://parts.digikey.com/1/parts/432147-rect-bridge-3-pha-800v-35a-d-63-36mt80.html

$15 is steep, compared to the Radio Shack 2-phase rectifiers that are only $3 each.  But it was worth it to only have a single rectifier for all 3 phases.  It's worked great so far, too.  Compared to the original selenium rectifier, the size is hard to beat!



Thanks for all the comments, guys.  It's given me a good bit to think about.  Being my first build, I'm sure I'd regret parting with it.  But, in order to fund my next couple of builds (and pick up a new welder, if I'm really lucky  ), it would be an asset.  I'll think it over a good while before I do anything.  And in the meantime, I'll ride and enjoy it.

You're not going to be happy with the power deficit if you go to a 350 twin.

~Joe

No doubt the 350 would pale in comparison on power.  I just love the idea of some small little "city bike", if you will.  Plus it would be easier to get the g.f. interested in learning ro ride.  I think the size and weight of the 750 intimidates her.  I think a smaller bike (I've even checked out CB175's and 200's) would just be a second, supplementary bike, not my primary ride.  And I could just pick it up and hang it on the wall when I need it out of the way 

[Old75_ratafe]

He said in that post with the picture that he is going to use thermal paste on that bare metal spot which effectivly turns the whole electronics box into a cooler for the rectifier.

P.S. I am loving this build.  I've been tring to decide what to paint my engine casing and this may have done it for me.

[tweakin]

Really nice build.  Where did you get the wintergreen oil?

[the architect]

Sorry to have not updated recently -- actually been riding this thing    Aaahhhhh . . .  the payoff on a completed build (or almost completed, since it never really is "done").

Really nice build.  Where did you get the wintergreen oil?

Tweakin -- I got the wintergreen oil from Amazon.com for $4 (for 4oz).  It worked great, and since I boiled with water, I didn't have to work with zylene.

http://www.amazon.com/Wintergreen-Oil-4oz/dp/B000NWGL6W/ref=sr_1_1?ie=UTF8&m=A1FRT2DFB93P69&s=generic&qid=1266429036&sr=1-1

He said in that post with the picture that he is going to use thermal paste on that bare metal spot which effectivly turns the whole electronics box into a cooler for the rectifier.

P.S. I am loving this build.  I've been tring to decide what to paint my engine casing and this may have done it for me.

Perceptive and brave for reading the whole build thread    I used the aforementioned thermal compound and bolted to the battery box.  So far so good.  When I've been riding, I can touch the area where the rectifier is mounted, and it's warm.  But it's also localized pretty much to just that spot, so it's certainly working to dissipate the heat.  On a tangent, the regulator is holding up good so far, too -- what a great buy at only $15!

Love the direction of this build. The brackets are awesome!

Great work!

.: Scott :.

Scott --  Thanks for the compliments on the brackets!  I'm getting some more together right now.  One day soon I'll actually set some good photos of them and get them on the "for sale" board to reach a broader audience.