Topic: 74 CB750K A Bike For My Pops

[FridgeRaider]

Hey guys, I wanted to document my 74 CB750K that I'm currently restoring for my Dad. I put my current build thread for my two 76 CB550s on hold to do this. I think in the long run it will be worth it. So here is a little back story:

I'm in the last months of my 4 year service in the military (stationed in Texas) and am planning on moving back to Florida to be around my family. While stationed here, I fell in love with the old Hondas and purchased a 78 CB750F. I promptly tore it apart, painted it, and put it back together in running condition. All of which was self taught, mostly due to this forum. My father expressed great interest in my new found hobby, my mother showed the exact opposite. As most of us know, it's hard to say no to just one and I found myself more projects. I picked up a couple of 76 CB550s to turn into cafe racers and document with a build thread on here. Again my father expressed great interest while my mother continued her disdain for motorcycles in general. The only issue was that my father liked the stock look over the cafe racer vision I had for my next projects. I decided to fix this by purchasing another project that would be done to his liking:





The bike itself is kind of a sad story. The previous owner I bought it from was a genuinely nice lady in her 50s. She said that she is the second owner of the bike and that she had bought it from her father (Original Owner) a couple decades ago. In 2001 her boyfriend of the time (I'm gonna assume not for long) was riding it to work and was side swiped down the left side. This accounts for the damage to the stator cover, engine guard, and all the other minor parts that stick out. She said she couldn't even bring herself to tell her father that it had been hit. So she put it in her shed and planned on eventually getting it repaired. Thirteen years later she gave up on that idea and decided to sell it to someone who would. I told her that my intention was to get it running so that my dad would have something to ride with me and I could see she was fighting back tears the whole time I was loading it onto my truck. I got the impression that her father wasn't around anymore and that this bike held a good deal of sentimental value to her. Once I'm done, I plan on sending her some pictures of it restored and maybe it will give her some closure. Hopefully it will become to my father and I what it was between her and her father, assuming I survive my mother's wrath for enabling my dad. I guess that is the upside to being 1200 miles away! 

[FridgeRaider]

My plan is to keep the stock look while upgrading all the wearable parts for better performance and safety. I have a home media blaster and cheap HF powder coating gun which gets great results for redoing all the original painted parts. I'm going to polish up the rest. 





The tank and side covers have a beautiful patina to them. The bad news is the tank sat 13 years half full of fuel. I couldn't believe how much rust was in it! I tried electrolysis but it wasn't making any progress so i ended up filling the tank with 1:1 ratio of Distilled Vinegar: Distilled Water and let it sit for 4 days. This did the trick and I treated the inside with Caswell's Epoxy Gas Tank Sealer. I highly recommend this sealer over Red Kote and Kreem. Unfortunately no pictures of this.

I decided to tackle the front end while i waited for the replacement parts for the engine. A big thanks to some of the guys on the forum, most of the parts were sourced out from them. 

Front wheel:





New bearings from All Balls



Polished the rim, spokes, and hub. Then I laced and trued it.







The rim had some bad rust spots where water had gotten past the spokes and started eating away the inside. Since I had some leftover Tank sealer, I had the brilliant idea to put it on all of the out of site areas that are prone to rust. It's impossible to tell but there is a thin coating of sealer on the inside of the rim in the previous picture encapsulating the rust. Hopefully this will prevent any more in the future. I also coated the inside of the front fender and tops of the fork tubes that are hidden behind the fork ears.

[Elan]

cool man, I always like some story behind a build too

[Stev-o]

Subscribed.  Let me know if you need anymore parts.

[Restoration Fan]

Awesome thread.  You're a good son.

Wish my son would make a motorcycle for me  .  Wait...ok...still a cool thing to do for your dad.

[FridgeRaider]

Let me know if you need anymore parts.

You're awesome I was able to pick and chose from the parts you gave me and now I have a working clutch! Pics coming.

Awesome thread.  You're a good son.

I think so! My father has a bunch of friends with expensive Harleys. I thought I would convert him to our side before he takes out a second mortgage.

a very cool trick is to apply a dab on the inside where each spoke penetrates the rim, thus making the rim airtight. Essentially could allow you to run a tubeless tire without a leak.  Or, should you get a hole in the tube, the tire would still hold air in a pinch.

Never thought to do that, I just figured a thin coating would help fight off future corrosion. Also I'm glad you commented, I was meaning to PM you about the Motogadget M-unit. I have been reading a bunch of threads and you seem to have the extensive knowledge when it comes to them (correct me if I'm wrong). If install one on this bike, can I retain all of the dummy lights (idle, oil, etc...) and if so, how difficult is it to do?

 

[FridgeRaider]

Worked my way up from the front rim. Media blasted the rotor and brake caliper then powder coated it a gloss black in my garage oven. The brake arm got a good polishing.



Kept the piston but replaced the seal and brake pads. Followed the advice of the many brake caliper rebuild threads and used Raybestos Brake Assembly Fluid on the seal and Dow Corning High Vacuum Grease behind the pads.

[Bill/BentON Racing]

Cool  build thread. You need anything, got a few parts, Bill G'luck.

[martin99]

Yeah, you're a good lad alright. Wish I could get my sons into bikes, they love riding with me but that's as far as it goes. They do have something in common with you though - fridge-raidin'!

Plenty of help to be had on here, looking forward to watching your progress - but promise you'll get rid of that sissy bar!

[FridgeRaider]

M Unit: easy to install, rugged, and feature-rich.

Great Input! I think that has tipped the scale in favor of installing one on the bike when the time comes. As for the solid state reg/rec replacement, which one would you suggest?

but promise you'll get rid of that sissy bar!

Already did 

Cool  build thread. You need anything, got a few parts, Bill G'luck.

Much appreciated!

[FridgeRaider]

So when I first got the bike, I was cruising the internet to find the best method/products to polish all the shiny parts such as the fenders, fork ears, and rims that have their share of rust. I figured since they are plated, they wouldn't fair well to the normal polishing method of sandpaper/polishing compound. Luckily for me I came across a Jay Leno's Garage Episode where they featured an American made product called Quick-Glo that brings rusty/oxidized metal back to a brilliant shine.



Here's Jay Leno's vid: https://www.youtube.com/watch?v=v7TnNEBy3tI

Pretty darn expensive with a $14 price tag when you can get an equivalent small sized tub of Mother's for $5 and some change. I bought it and compared it to Mother's, Autosol Metal Polish, and Nevr-dull. The winner if you haven't guessed it yet is over-whelming Quick-glo. It removes all of the minor to moderate rust spots and heavy oxidation with a little bit of elbow grease. Only issue is it does leave some very minor scratches but I think that is more from the rust that was removed and trapped in the rag.

 

   

I've been using it to polish up pretty much all the sensitive parts. I also found out, too much elbow grease and you run the risk of rubbing off the black on the tach/speedo gauges.

[FridgeRaider]

Realize, neither is a stock bolt in and each will require slight fabrication to mount.

Fair enough, custom fabrication is not an issue for me. I have read a couple of threads about using a modern small engine regulator and rectifier as opposed to the more expensive Oregon/Rick's option. I personally prefer the latter, but what would be the downside of running the cheaper option seeing as how you have to custom wire each one anyways?

Pinhead's Regulator replacement thread for reference: http://forums.sohc4.net/index.php?topic=121646.0 

[FridgeRaider]

Next up: Rebuilt and polished the front forks. Replaced the old worn out springs with new Progressive Suspension Fork Springs 11-1104 and filled them with Bel-Ray 15W Fork Oil.

[FridgeRaider]

I've never seen "cheaper" and "MotoGadget" used in the same thread by anyone planning on using an m-unit 

Other vehicle type options will work as long as you find one compatible with sohc stator (yep, they're out there). I'd also just make sure you confirm its compatibility with the battery type too if you are planning on running Li-type.

More money does not always mean a better product, just better marketing.    I'm leaning towards Rick's none the less. Will there be any issue with a Lithium battery such as the ones made by Shorai? They seem to be the overwhelming choice for those doing a cafe racer build. I did a little reading on them and there are differing opinions on whether our bikes are able to properly keep them balanced without the help of the Shorai charger. My second choice would be the highly recommended Scorpion AGM. Thoughts?

http://shoraipower.com/products?action=vehicle&type=175&make=942&model=7575&year=7575

[FridgeRaider]

A word of caution though: they can be temperamental on over-discharging. This becomes and issue only while wiring and tuning your bike, not while operating if the charging system is healthy. That's partly why I like the m-unit. You can disconnect the circuits individually until you have the entire bike functioning correctly, then connect all circuits. Of course, you can keep a charger attached while testing to avoid the over-discharge.

As always thanks for the info! The bike's old battery is toast so I will just swap in the working one from my 78' for now until i decide on Shorai or Scorpion AGM.

[FridgeRaider]

It seems a snail lived out it's short life under the dummy lights in the depths of the triple tree, gauges, and headlight bucket:



The snail was buried with full honors and the triple tree got a well needed over haul. With the front forks and wheel off, it was easy to tell that the original steering bearings were done. When turning the handle bars, it had a very prominent snap back to the straight ahead position, which in Hondaman's book said was due to the races being dimpled from the ball bearings. It didn't matter to me because I already had an All Balls tapered steering bearing kit (22-1011) in the mail. Installation was fairly easy and straight forward: drift out the old races, add the new ones in their place. I did this with the help of an all thread rod and washer/nut attached to either side. Slowly tightening the nut made for even pressure on the entire race as opposed to seating it with a drift. Since I was planning on using the stock headlight ears, I took a dremel and grinded down the extruding tabs on the inside of the steering stem nut. This removed the gap the top tapered bearing created. The upper and lower triple got a good sandblasting and at home powder coating.



I made sure the handle bar clamp/dummy light cluster matched the fresh triple tree. Here it is, old and tired looking with the plastic and thin metal plate still in decent shape:



Since I would be putting it in the oven at 400F or so to cure, I need to remove the colored plastic pieces. The metal plate holds them in place and glue holds the metal plate. I borrowed my buddy's girlfriend's hair dryer and let it sit on high for a bit.



It heated up the old glue and I was able to slowly work a scalpel underneath the plate. Here's what it looks like once removed (ignore the ratchet, that thing likes to wander into my shots).



Now it can be safely powder coated and glued back together.

[FridgeRaider]

A box of goodies came in the mail and included was an 18 tooth front steel sprocket from JT. I replaced the front sprocket but I have a couple of questions about the install. I know on the later years (77-78) they ran a 630 chain and the front sprocket had an offset to it. This means it could only be installed facing one way. Is this the same for the earlier 530 chain sprockets? because I couldn't tell a difference one way or the other but I could be wrong. Secondly, What is the rule of thumb for setting the chain oiler? Is it hand tightened or torqued to a specific range?

[FridgeRaider]

I have been talking to my father about the bike and asking his opinion on what he wants done with it. It normally goes along the lines of:

Me: "hey I think we should replace the regulator/rectifier with a modern one." 
Pops: "Do it!............what does a regulator/rectifier do again?"

Needless to say, he trusts me with the technical decisions. One of which, was that I wanted to replace all of the old nuts and bolts with new stainless steel fasteners. As I have been taking each part off of the bike, I've logged the bolt sizes for replacement. I decided to order through http://www.mrmetric.com/ since they seem to always be running a 20% off promo and no minimum order. I would say they have about 90% of the bolts I am looking for. The main downside is that they don't offer M10 or bigger in fine thread sizes and the allen head bolts aren't labeled smooth or knurled so it is a toss up until you get them in person. I make sure to put anti-seize on all the threads when mating stainless steel to the aluminum cases and others. This will help prevent the issue of galvanic corrosion. They even sell the retaining rings (in steel) for the fork seals, a grand total of $1.50 for the pair.

Here is one of my orders, all of the bolts separated by size and neatly labeled.


What the old replaced hardware looks like. I spent a painful amount of time removing the rusted, stripped out JIS screws. Thank you Honda 

[FridgeRaider]

You might find the odd pieces you seek at allensfasteners.com. Conversely, you could have bought all the side cover bolts labeled and packaged from AlloyBoltz.com.

File away for next time....

The difference doesn't bother me (barely noticeable anways), but I will remember AlloyBoltz.com when I make a CB750 show bike for Sturgis

[HondaMan]

A box of goodies came in the mail and included was an 18 tooth front steel sprocket from JT. I replaced the front sprocket but I have a couple of questions about the install. I know on the later years (77-78) they ran a 630 chain and the front sprocket had an offset to it. This means it could only be installed facing one way. Is this the same for the earlier 530 chain sprockets? because I couldn't tell a difference one way or the other but I could be wrong. Secondly, What is the rule of thumb for setting the chain oiler? Is it hand tightened or torqued to a specific range?

The 530-size sprocket on these earlier bikes is "spaced" by that spacer washer (or a shoulder on the sprocket, if you got that type) to offset it. If the sprocket does not have 2 [big] washers with it, put the washer BEHIND the sprocket to push it outward a little bit (2mm, technically...). Then slip on the little toothed plate.

If you have a fine-stone grinder handy, try modding that JT countersprocket a little and be rewarded with smoother operation, quieter chain, and longer life: trim the tips of every tooth about 2mm shorter, and then apply a 45 degree side angle between the egdes of each tooth and the sides. This only takes about 10 minutes (at least, after I have done about 20 of them lately) and will make you chain much happier and will reduce the tendency to pitch off the lube as it is running.

The oiler: Honda set them at 1.5 turns out from closed on the 1974 and later bikes. That often let the chain run pretty dry, though. The little rubber seal on the screw is probably shrunk from age by now, so it may oil well at that setting today?

[Lazerviking]

Really digging this build and your attention to detail. I need to add a small blaster and a powder coating system to my basement. Do you use a booth for blasting your parts?

[FridgeRaider]

Really digging this build and your attention to detail. I need to add a small blaster and a powder coating system to my basement. Do you use a booth for blasting your parts?

Hey Lazerviking thanks for the reading! At the very least home blasting is the way to go.  I built a big blasting cabinet that can house a motorcycle frame (still haven't built an oven big enough to compliment it  ).



I use a modified powder coating gun from harbor freight and a small wall oven to cure them in. 90% of the final finish is in the prep work so I can get great results (not professional, but close) for a fraction of the cost. Plus, I can say I did all the work myself. 

The 530-size sprocket on these earlier bikes is "spaced" by that spacer washer (or a shoulder on the sprocket, if you got that type) to offset it. If the sprocket does not have 2 [big] washers with it, put the washer BEHIND the sprocket to push it outward a little bit (2mm, technically...). Then slip on the little toothed plate.

If you have a fine-stone grinder handy, try modding that JT countersprocket a little and be rewarded with smoother operation, quieter chain, and longer life: trim the tips of every tooth about 2mm shorter, and then apply a 45 degree side angle between the egdes of each tooth and the sides. This only takes about 10 minutes (at least, after I have done about 20 of them lately) and will make you chain much happier and will reduce the tendency to pitch off the lube as it is running.

The oiler: Honda set them at 1.5 turns out from closed on the 1974 and later bikes. That often let the chain run pretty dry, though. The little rubber seal on the screw is probably shrunk from age by now, so it may oil well at that setting today?

Awesome advice! I had to run into the garage at 1 a.m. to modify the sprocket. It took me a little more than 10 mins but overall it was pretty easy.

Before:



After:



I would have posted this earlier but I had a lady friend fly into town the next day so she took precedence over motorcycle work. Let me know how it looks!

[FridgeRaider]

This is method I used. I pulled out my digital caliper and locked it to 2mm. It has a depth gauge that extends out of the bottom which can be used to mark each tooth. I sharpied the 2mm but came to realize that it is easy to lose the mark when going at it with my dremel. I remedied this with painters tape as a mark of what not to grind.









Tips grinded down, before chamfering them:



Final results:





The fine grinding bit on my dremel started giving them a bit of a rounded bevel a couple teeth in due to wear (hopefully that wont affect performance). Ultimately I'm happy with the results and with the teeth being 2mm shorter, I think i can put the crankcase protector (against broken chains) back on without clearance issues. Thanks HondaMan!

[Brittreynolds93]

Wonderful project. Great attention to detail, can't wait to see the finished project!

[FridgeRaider]

Front of the bike mocked up before tire install:





Decided to go with stock tire sizes that came on the bike in 1974. Avon Roadriders seemed to get nothing but awesome reviews from you guys so it was an easy choice. 

3.25-19 Front 4.00-18 Rear



I spent a month or so waiting out the holidays hoping they would go on sale but never did.  Darn you tire manufacturers and your set prices!

Beautiful tires none the less and were much easier to work with as compared to the old stiff tires I took off. With a little bit of elbow grease, tire spoons, and a product called Ru-glyde: