Author Topic: 1971 CB750 Resto project... (Read 4543 times)

Red67lemans326 · « **on:** January 20, 2011, 07:18:31 PM »

There are ALOT of things i did not taken pictures of...i should have taken pictures of everything...but i work very fast and my roommates are dis-interested.

I picked up my 71 cb750 from a local man here in Florida, who happened to be the original owner.
The bike was absolute rubbish when i picked it up for 100 dollars...with a title.

I need a top end gasket set...and i REALLY don't wanna buy a POS one...Which should i get?!

Also...My engine cases have NO numbers on them (above the sprocket cover)...what does that mean? (replacement cases from honda?)

Things done so far:
complete dis-assembly
Frame/swing arm sand blasted and painted. (Harbor freight sand blaster and my compressor! and a lot of protective gear)
Front forks rebuilt (new seals and fresh oil)
cleaned EVERYTHING (I think the owner thought it was a dirt bike...good god)
Stripped tank, and found bondo! WOOO

(used TAL STRIP II Aircraft coating remover...whatever you do, read the instructions.)
The races were is very good shape so i re-used the old bearings and races with new grease

Here's a good one: The top triple was cracked around the clamps...SOOOO....(Not sure if i should have done this) I filed into the cracks with a sharp edged file until i was past the crack. Had a friend of mine weld and fill in the places I had filed, where the cracks used to be, sanded, painted, viola the world is none the wiser....what do you guys think? (i have doubts about it's strength...we'll find out! $:-\$ )

Bike came with nothing good...no tank, no gauges, no side covers, no tail light. ect. BUT haha the seat was in 99.9% perfect condition...how...I'll never know.
He stored the bike outside under a tarp tent....with the spark plus OUT!!!!!!!!!!....

(seized motor = major headache)
Needless to say everything was roached, but i was/am determined to bring this thing back to life and beauty!

Things to come:
Paint - Original gold
Exhaust - Need to buy...what's my best bang for my buck?
Re-spoke the wheels
Top end rebuild
and more...

I'm gonna go with an original restoration on this, No cafe this time. Keepin it classy.
BTW I'm a 22 year old Broke college student.....and my resto is only 2 months behind schedule (so far). Expected running/riding completion date: April 10th, 2011 (mind you that's including a two week tour in march all over FL with a band called The Slackers)

(^Tank in primer, soon to do the side covers, fork ears, and headlight bucket^)

(^Spent a couple hours polishing a spare set of fork legs...here's the before and after^)

Pardon the gigantic mess in my garage lol (You can't see the 3 CBR's behind the camera, Ones mine, ones my room mates, and I'm fixing one a friend just bought, and it's a nightmare.)
Any suggestions or advice would be greatly appreciated! I am open minded and want your guidance!

Old Scrambler · « **Reply #1 on:** January 20, 2011, 07:31:14 PM »

You can expect the bottom end to have moisture...........at a minimum drop the oil pan and inspect the crank (possibly clean and then lube with any kind of oil at every bearing before you rotate.

Advise looking at rebuild of Sandcast #97 title on the Projects page.

Stev-o · « **Reply #2 on:** January 20, 2011, 07:37:07 PM »

First off, welcome!

Lots of questions, I'll answer a few:

Cases with no numbers are mos tlikely replacements due to cranked case from a broken chain, fairly common.

If you question the strength of the trip tree, buy another! About $30 on eBay.

Mac makes the "best bang for your buck new exhaust". Or you can find a used 4 into 1 for about $125. Start shopping.

Franenstuff, a member on this forum makes sidecovers for $72 shipped, check the For Sale threads.

If the motor is "stuck", try pouring ATF/Acetone in the cylinder and let it sok for a few days, it worked on my 750!

Nice job on the fork! and tank.

Good Luck.

tango911 · « **Reply #3 on:** January 20, 2011, 08:01:40 PM »

looking good so far, im doing a K2 myself and am almost done. Its quite the learning experience but well worth it. Good luck im watchin.

Red67lemans326 · « **Reply #4 on:** January 20, 2011, 09:04:35 PM »

Thanks all for your advice!
I have side covers though they have been repaired...long ago, resin and a patch style
I have a 1971 motor that i bought as a spare which is also seized. but for 30 bucks with perfect covers I could polish...hmmm couldn't resist.
I've got the motor apart now, Things look pretty promising.

This isn't my first rodeo...but it's my first Frame up rodeo. My father got me started on this restoration thing with 60's and 70's muscle cars. and me doing this CB750 is kind of a symbol to here dad...you taught me everything i know and here's a motorcycle I restored to show it!

But how far into the rabbit hole do i want to go?...I do all the hard things myself...Hone the cylinders, rebuild the top end and inspect bottom end, Paint work, Blasting, Polishing, Cleaning, Parts hunting. And i'm still looking at around 2500$ cost to get it "acceptable" in my mind

What are your thoughts on http://www.cyclexchange.net/Exhaust%20System%20Page.htm (not the drag pipes, dear god...)

tango911 · « **Reply #5 on:** January 21, 2011, 05:47:57 AM »

where you from sir?

Red67lemans326 · « **Reply #6 on:** January 21, 2011, 08:27:27 AM »

Gainesville, FL

Stev-o · « **Reply #7 on:** January 21, 2011, 05:53:27 PM »

What do you think of this cycle x exhaust for $229?

http://cgi.ebay.com/ebaymotors/Honda-cb750-Performance-4-into-1-Exhaust-Cafe-Bobber-_W0QQcmdZViewItemQQhashZitem2eb1191c53QQitemZ200539708499QQptZMotorcyclesQ5fPartsQ5fAccessories

Red67lemans326 · « **Reply #8 on:** January 21, 2011, 07:34:28 PM »

That looks pretty sweet to me...but it'll have to wait. i'll be sure to give everyone a good laugh as i put the pipes that came with the bike back on for testing purposes

There are a lot of things that I am drooling over and can't wait to get (new gauge face plates, nicer exhaust ect...) but things like...
The motor build
Battery
Chain
Brakes
Paint
Wheel bearings
ect. take priority

Coming next week: Re-spoke the wheels and paint. I am considering going to my local paint supplier and asking if he can get close to the original gold...without blowing $250 from vintage-honda-paint. What are thoughts on this? has anyone done this in the past?

Stev-o · « **Reply #9 on:** January 21, 2011, 07:42:22 PM »

Yes, take your tank or sidecover to a good auto paint store, that what my painter did for me.
It's not an exact match, but we're not going for concours, right?!!

Red67lemans326 · « **Reply #10 on:** January 22, 2011, 03:06:49 PM »

Ordered the Gasket set (Athena, made in italy)
and 4 sets of stock size TP piston rings today $175 for gasket set and rings to the door from OldBikeBarn.com

I have a very good relationship with my mechanic, and he let's me go in and do my own stuff when he's not busy, and answers any questions i have...gotta love it.
My Bore was 61.02mm, 3 spots checked top, middle, and bottom in each cylinder!

Took the head apart, valve guides had NO play in them, Though the valves didn't come right out, I had to de-bur the edge to get them to drop out.
He spoke of Sending the pistons off to a company in TX to have them "refinished" with a Teflon coating for about 25$ a piston...thoughts? knowledge?

Also....to order a cam chain...or not...?...I already have the blasted thing apart... $:-\$

I have several options for case covers to polish up and put on...I have a Finned Points cover, or chrome "Honda" one. Which do people prefer?....are the finned ones hard to come by?

I was looking into http://www.buchananspokes.net/products/spoke_kits_honda_cb.asp
I know Stainless is the way to go, but does anyone know of anywhere a little cheaper for spokes?
Pictures coming soon...

fire113 · « **Reply #11 on:** January 22, 2011, 05:42:43 PM »

Quote from: Red67lemans326 on January 20, 2011, 07:18:31 PM

I picked up my 71 cb750 from a local man here in Florida, who happened to be the original owner.
The bike was absolute rubbish when i picked it up for 100 dollars...with a title.

Also...My engine cases have NO numbers on them (above the sprocket cover)...what does that mean? (replacement cases from honda?)

Bike came with nothing good...no tank, no gauges, no side covers, no tail light. ect. BUT haha the seat was in 99.9% perfect condition...how...I'll never know.
He stored the bike outside under a tarp tent....with the spark plus OUT!!!!!!!!!!.... (seized motor = major headache)
Needless to say everything was roached, but i was/am determined to bring this thing back to life and beauty!

Hey mate,

...sounds like my K0 that I bought last september-->
no gas tank, no seat, no gauges, no engine number, no rear fender, no/wrong front fender, wrong oil tank, wrong fork (K1), no HM300 only a 4 in nothing...
The engine looks real bad but starts up by the first kick --> http://www.steffens-hotel.net/HGS/HONDA/K0.wmv
Here is a picture from september as I bought it, right now I have tho most things together was real hard to find the K0 parts.

Have a good one....Georg

Bluto · « **Reply #12 on:** January 22, 2011, 06:40:47 PM »

Hey Red,

How bout sharing the details on how you got the fork legs to polish up so nice.........looks good.

Thx

Red67lemans326 · « **Reply #13 on:** January 22, 2011, 11:35:42 PM »

First off DO NOT Sand Blast aluminum motor parts, The sand embeds itself into the metal and when heated will release, then it becomes Sand + Motor = bad

I did not sand blast that leg.

Things you will need:
3 hours of your time, and the will to push past any pain you THINK your arms have felt until this point.
400 grit sand paper (this is for the REALLY bad stuff...otherwise just start with the 600)

600 grit, don't be discouraged that it looks like you're marring the hell out of your aluminum... it'll come out fine in the end

1200 grit you may think it will look good after 5 min of using the 1200....but the more you do it the better the finish gets
1500 grit...This is the 2nd to last stage and not 100% necessary the 1200 will do just fine...I just happened to have 1500 laying around and gave it a quick once over
Mothers "Mag wheel & aluminum polish" (This is the best 8 bucks you'll spend..ever and a little goes a long way just follow the instructions)

IF! you are Superiorly pleased with your finish...clean it off with some break clean, let it dry and gloss clear coat it(doesn't matter what kind)...it will last a long time with less frequent "touch ups" from the mothers polish.

REMEMBER!....Wear Latex, Vinyl, or Nitrile Gloves when doing this, and don't touch your face....EVER! metal particles could get in your eye...absorb through nasal membrane...and if you have a mask/respirator please wear it....Tiny aluminum particles in the lungs is not good.

fire113 · « **Reply #14 on:** January 23, 2011, 03:55:25 AM »

1+ on You instruction.

ALWAYS WEAR A FULL FACE GAS MASK BY THIS KIND OF WORK

I start with 400,600,800,1000 and the 1200 wet and after it the item will be polished with a polish disk
I let them only polished without coating.

EDIT--> That fork that You have polished isn't K1!!!

Have a good one mate...Georg

Stev-o · « **Reply #15 on:** January 23, 2011, 08:35:31 AM »

A lot of guys like the finned points cover, they are not that hard to find. I'm looking for a chrome points cover in very good cond, want to sell if you don't use it?

CB750supply sells spokes too...

http://www.cb750supply.com/products/2/chassis-brakes/61/wheel-spokes

Red67lemans326 · « **Reply #16 on:** January 23, 2011, 10:35:39 AM »

Quote from: fire113 on January 23, 2011, 03:55:25 AM

EDIT--> That fork that You have polished isn't K1!!!

Yeah the K1 is the nasty fork that has yet to be polished. The polished fork in the picture is off a K3, sorry if i said different

I think i'm just gonna bite the bullit and get the stainless spokes....I never want to do this again...on this bike.

I think I'll polish up the finned cover and paint between the fins with black...should set it off nicely. I'll go home and try to get all the covers off *prays* and get a big head start on the polishing. Pictures to come! I'll actually do b4 and after ones this time!

Red67lemans326 · « **Reply #17 on:** January 27, 2011, 06:58:06 PM »

What are you guys thoughts on...
http://cgi.ebay.com/ebaymotors/HONDA-CB750-SOHC-POLISHED-STAINLESS-BOLT-KIT-CHOPPER-/370478297517
I have all the cases off and will be making a new thread on "How to Properly Polish Aluminium" and show before during and after with the correct equipment....
but when i put them back on...I want Allen heads. I saved and didn't ruin any of the original bolts in case I ever sell the bike, so that I can offer the OEM screws.
My gasket set came in (athena), and piston rings(TP piston rings, Made in japan [Box is red and says RICK..or RIK])
The edges of my piston rings feel/look very nice...compared to some Taiwanese pistons rings.
I looked at a set of both them under a magnifying glass, I was amazed at the nicks and chips in the Taiwanese rings compared to Japanese. (amazed...not surprised)
Saturday will be the day I polish these damn case covers!

Red67lemans326 · « **Reply #18 on:** February 03, 2011, 03:31:38 PM »

OMG OK...Lot's of new stuff...I've been very very busy. New thread coming on how to polish aluminum...the hard way.
Doing the electrolysis method i saw here http://www.altelco.net/~jacil/clay/motorcycle/KElecSetup.html

Mixed up 5 gallons...put it in the tank

So...My battery charger is smart and won't put a charge to anything that's not a battery....but i outsmarted it...with this spare Deep cycle marine RV battery i had laying around lol

I hope it works....i'm kinda excited to see how it goes...it's only been soaking for about 20 min... as of 6:00pm EST

I ordered a tail light...and i hadn't looked at my K1 fender...and bought a later model tail light...FML i need a K1 tail light plz help!

^fits in these holes....^ I'm gonna leave the AAA sticker...cuz the owner was really sad to see his bike go. and it's super old and i like that.
Note: that's just dust and what not from sanding.

fire113 · « **Reply #19 on:** February 04, 2011, 06:58:49 AM »

...be careful ! As I know You are going to produce oxygen and hydrogen with the electrolyses of water.

Good luck...Georg

nhodges · « **Reply #20 on:** February 04, 2011, 09:53:04 AM »

That's really cool, gonna have to give it a try....post how long it took and how well it cleaned the rust. thanx

Ernest T · « **Reply #21 on:** February 04, 2011, 03:37:25 PM »

Quote from: Red67lemans326 on January 22, 2011, 03:06:49 PM

Ordered the Gasket set (Athena, made in italy)
and 4 sets of stock size TP piston rings today $175 for gasket set and rings to the door from OldBikeBarn.com

I have a very good relationship with my mechanic, and he let's me go in and do my own stuff when he's not busy, and answers any questions i have...gotta love it.
My Bore was 61.02mm, 3 spots checked top, middle, and bottom in each cylinder!
Took the head apart, valve guides had NO play in them, Though the valves didn't come right out, I had to de-bur the edge to get them to drop out.
He spoke of Sending the pistons off to a company in TX to have them "refinished" with a Teflon coating for about 25$ a piston...thoughts? knowledge?

Also....to order a cam chain...or not...?...I already have the blasted thing apart... $:-\$

I have several options for case covers to polish up and put on...I have a Finned Points cover, or chrome "Honda" one. Which do people prefer?....are the finned ones hard to come by?

I was looking into http://www.buchananspokes.net/products/spoke_kits_honda_cb.asp
I know Stainless is the way to go, but does anyone know of anywhere a little cheaper for spokes?
Pictures coming soon...

Buchanon's is the way to go, they do great work.

Ernest T · « **Reply #22 on:** February 04, 2011, 03:49:12 PM »

Quote from: Red67lemans326 on January 27, 2011, 06:58:06 PM

What are you guys thoughts on...
http://cgi.ebay.com/ebaymotors/HONDA-CB750-SOHC-POLISHED-STAINLESS-BOLT-KIT-CHOPPER-/370478297517
I have all the cases off and will be making a new thread on "How to Properly Polish Aluminium" and show before during and after with the correct equipment....
but when i put them back on...I want Allen heads. I saved and didn't ruin any of the original bolts in case I ever sell the bike, so that I can offer the OEM screws.
My gasket set came in (athena), and piston rings(TP piston rings, Made in japan [Box is red and says RICK..or RIK])
The edges of my piston rings feel/look very nice...compared to some Taiwanese pistons rings.
I looked at a set of both them under a magnifying glass, I was amazed at the nicks and chips in the Taiwanese rings compared to Japanese. (amazed...not surprised)
Saturday will be the day I polish these damn case covers!

The newer Honda's (80s) have chrome hex bolts on the engine cases and I have been retrofitting all my older bikes with them.

Here's the part number: 96001-06032-02 The middle numbers are the diameter and length. Just replace them with the size you need. 06070 is a 6 mm 70 mm long chrome hex bolt. Verify the size you need exists on one of the dealer sites.

Red67lemans326 · « **Reply #23 on:** February 05, 2011, 12:03:07 AM »

This was after (waaaaay too long) a 19 hour soak, thanks to my work holding my during my lunch break.
it works!...but i need to find a new nonmetallic object to hold the anode in place...
after 4 hours the anode is covered in crap....Now...as you can see the water in the tank is very cloudy...i will continue to monitor it and scrape the anode every couple of hours...

Stev-o · « **Reply #24 on:** February 13, 2011, 08:34:03 PM »

The stainless bolt kit appears to be a good deal, I may get one too.
An anti-seize product is recommended to be put on the threads of the screws to prevent corrosion of the unlike metals.

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Author Topic: 1971 CB750 Resto project... (Read 4543 times)