Topic: Texas Barn Find - 1974 CB750K4 - HELP ME OUT!!!

[Stev-o]

I'm sure you can get a copy of the title just don't know the procedure if the owner is diseased.

Call the DMV for details....


http://www.txdmv.gov/motorists/buying-or-selling-a-vehicle/get-a-copy-of-your-title

[Funkenstein]

This bike is still revealing it's secrets so come along as I show you hidden compartments, rusty pipes and amber lights. First up is the gas tank! it looks as bad as it smells!


Next are the pipes. They've got some rust pitting and spotting from my inferior cycle wash but hopefully it provides enough info as to condition. They look clean on their lower most parts. They're staying put so hopefully a little polish is all they need.





This brings me to the contents of the saddlebags. I laid them out on a table and was hoping to get some advice. These photos were just for fun:


I know what most of the tools are but can someone chime in and tell me what the mystery tools are? Tool #1, #2, #3, #4?



Last update for tonight, a secret hidden compartment! Did a spy own this bike? A drug smuggler?? After I figured out that the seat was on hinges, I was taking a pic of the battery and saw a door. It was built into the seat! Check it out:

I opened it and found another time capsule moment. The original owner's manual still sealed in the original ziplock baggie.




Thanks to everyone for all the advice. I'm planning on doing some work Saturday morning so I'll be posting what I want to do and more pictures!

[Stev-o]

That tank is horrific!   You may want to try the electrolysis method to derust it.

The circular wrench is used to adjust the preload on the rear shocks.  Those pipes are in good shape. Most have been thrown or rusted away decades ago!

[754]

When you get ready to start it , if the oil is down, only add a quart..it's probably. Hiding in the sump, and will pump back up when it starts.. Makes a big mess if you add too much..

[SOHC4 Cafe Racer Fan]

Funkenstein,

I love Austin, ACL and the Festival. My girlfriend and I went to the festival (weekend one) last year and fell in love with Austin.  What a cool city.  I love the program, too -- especially the classic performances from SRV.

[edwardmorris]

Welcome and a great find! Congratulations! This is very similar to another recent member's 750 (milla I think??), very good looking color for its age. I see you're in ample supply of sound advice, so I won't bore you with another task list  Keep us posted, we love pix and stock restos!

PS: Digging the morse code for SOHC4 in your sig

[calj737]

I'm with Stev-o on using electrolysis for the rust removal in the tank. Whichever method you choose, avoid at all costs chemicals that can damage your paint.

MetalRescue for the metal parts will be invaluable.
#1 - shock adjustment spanner wrench
#2 - fork top nut, steering nut removal wrench
#3 - dont recall
#4 - I think is the tire iron?

[70CB750]

#4 is spoke wrench.

[calj737]

#4 is spoke wrench.

Right! Oddly enough, I looked at it, and said, "What the hell is that called again?" Sucks getting older and older and... Dang, forgot what I meant to say 

[oldhatt45]

Funkenstein,

#1 serves 2 purposes. First is the Rear Shock Adjustment.  Second is the Spanner Nut under the Top Triple Tree.
#2 is for the Rear Axle Nut as well as the chrome nut on the top of the top triple tree
#3 is a T handle for the screwdrivers
#4 is a Spoke wrench for tightening the spokes on the wheels.

I forgot to mention something which just occurred to me.
You need to check and see how much Oil is in the Oil Pan.  First, drain the Oil from the Oil Tank on the Right Side there should be around 2+ quarts in there.  Next, There is a drain screw in the Oil Pan.  Remove this screw with an oil catch pan under the bike.  If there is more than about half a quart, it is very likely that the Oil Stopper in the Oil Pump has leaked and the engine has wet sumped.  A member Elan sells a complete rebuild kit for our Oil Pumps.  You might want to pick up one of his kits and rebuild the Oil Pump.  http://forums.sohc4.net/index.php/topic,145425.0.html

There are several on the forum here that can provide info on cleaning the mufflers. 

Since you have ordered the Hondaman Book I would suggest that before doing anything serious, you read the Book at least twice before taking a wrench to the bike.     

That gas tank looks "gas-tley"  Hahahaha   I just finished cleaning my tank which wasn't anywhere near that bad. 
There are several methods for tank cleaning and the electrolysis method mentioned by Stev-o seems like the way to go by those that have been in your situation.

Nice Pics. 

Charlie

[eddiebpool]

What a find!  Great bike, I hope you get the old girl running.

I did an electrolysis experiment on my tank and it worked very well.  I'm sure others have come up with other methods that might be better than mine, but here it is if you want to give it a go:

http://forums.sohc4.net/index.php/topic,137248.25.html

The rust had gone through the tank and there were little pinholes.  I had to strip the tank, fill the holes, then do a tank liner job.  I hope you don't have the same and you have to take off that beautiful paint.

Good luck with the restoration.

[Johnie]

Yes, try to clean that tank yourself. Some guys take it to a radiator shop to clean it, but shops are not real careful and the chance it comes back with damage to the paint and maybe dents is a sure possibility. It would be a shame to damage that OEM paint. You have a real gem there. Your owners manual is pristine and will provide you with good info on oil and filter change, tune ups, etc. The Hondaman book will provide the rest. You will probably end up installing new fork seals too. Those are still available from Honda and are very good quality.

One more tip...as routine I always clean out the bottom of the oil tank which is located under the painted right side cover. This has the chrome oil cap on it. There is usually a bunch of sludge in there at the bottom. Not sure if your bike with under 1,000 miles will have sludge, but may as well check it out.

[seanbarney41]

I am not really seeing very much rust in that tank, just a #$%* TON of old dried up gas and dirt.  I would try to clean it as gently as possible first.  If gentle paint safe methods don't clean it out, you can always step up to the messy stuff later.   SAVE THAT PAINT!   The originality of this bike is what makes it extremely rare and special, even if the bike is not as perfectly brand new as a multi thousand dollar restoration.

[Desert-SOHC]

I believe that #2 is the rear axle nut wrench for adjusting your chain.

[70CB750]

I believe that #2 is the rear axle nut wrench for adjusting your chain.

Yes, #2 and the flatten piece of tubing on the very right.

[Johnie]

Agreed that tank inside looks pretty crappy. How do you guys think Metal Rescue would do? Maybe doing that before the electrolysis. Hard to tell from the pic what I am seeing in there...rust, old gas, dirt, etc? Probably all the above. I have never used Metal Rescue before so for you guys who have used it what do you think?

[70CB750]

I used Purple Power back in the day when I was trying to get the tarnish like old gas out of Dorothy's tank.  It work OK.

[calj737]

yeah, first order of business is a good old fashioned soap and water cleaning! But theres no doubt that rust is inside that tank given the underside of the filler cap. Let's just hope that the rust has eaten pinholes into the floor plates or behind the badges 

[SOHC4 Cafe Racer Fan]

yeah, first order of business is a good old fashioned soap and water cleaning! But theres no doubt that rust is inside that tank given the underside of the filler cap. Let's just hope that the rust has NOT eaten pinholes into the floor plates or behind the badges 

FTFY
Yes, let's hope. Once you get it clean you can pressure test for leaks.

[2strokeTrush]

Wow talk about a nice barn find. Great looking bike!

[HondaMan]

What a find! A wedding-day-only K4, wow!

That has to be the most unmolested Bates Fairing and Bag set I've seen in 30 years! Most of them did not survive long, as the brackets for the fairing were simply layered into the inner shell, and they broke out after a few summers of riding. The bags usually cracked along their mounting bolt holes, too. The latter can be prevented (or at least delayed a long time) by using a sheet of metal on the insides of the bags to "back up" the bolts and spread the torque across a large area: this saved many of those bags.

[oldhatt45]

As far as the tank goes, I just used the Klean & Strip brand Prep & Etch product (1 Gallon) and it worked very well.  But then my tank wasn't near as bad as this one.  For $15.00 at Home Depot it might be worth a shot.  (And a couple dollars for the Arm & Hammer Baking Soda to neutralize the Acid reaction.)

Hondaman,

You're right about the Bates Fairing and bags.  Several people back in the day had problems that I remember with the fairing brackets coming loose from the back of the fairing.  And the inventive ways of holding it together until they got home was interesting as well.   

Charlie

[CBGhia]

You need to drag yourself out to the Harvest Classic next month!  Just down the road from Austin.

[Funkenstein]

Hey everybody! Thanks for the help identifying the tools! oldhatt45, I just ordered the "8 Piece Vessel JIS Mechanic's Shop Quality Screwdriver Set" from RRRToolSolutions like you recommended. Add another $75 to the total for the bike restore total. haha!

 I'm planning on doing some work to the bike on Saturday. Here's my to-do list which is still very much a work in progress.

Done:

• Buy lottery ticket!
• Buy hondaman's book!
• Buy JIS tool set.

Saturday:

• Remove side covers being very careful. Lube and press from the inside. Go slow!
• Remove gas tank. Clean with soap and water. Inspect and possibly use metal rescue. Electrolysis if still major rust present.
• Remove petcock, rebuild, repack
• Drain oil from oil tank. Drain oil from pan(if more than half a quart, oil stopper in the oil pump has leaked, needs rebuilt)
• Remove spark plugs and add 50/50 mix of ATF and Acetone to fill cylinders. Let it sit for a week.

Future:

• Rebuild front brakes, new pads, replace fluid, new SS brake lines(use heat to free master cylinder and caliper
• Rebuild Master Cylinder - Very likely the brake fluid had turned to Goooo.  (Use only DOT3 fluid)
• Rebuild Caliper - New O-Ring seal, New Stainless or Phenolic piston.
• Rebuild front suspension, fork seals, fork oil, tapered steering head bearings, progressive springs
• Refurbish swing arm with new grease
• New Sprockets and Chain.  Not from wear, but from age.  Sprockets are probably OK but the chain has probably rusted.
• Check the electrical connectors for oxidation.
• Remove carburetors, rebuild(harisuluv)
• Replace spark plugs with D8EA plugs
• Upgrade ignition(DynaS or Hondaman?)Decided to keep the points ignition
• Cam chains? Tensioners? Again, low mile bike would need this?
• Gasket set, piston rings, engine seal set?
• Porting the head?
• Inspect/Rebuild rear brakes?
• Rebuild/Upgrade rear suspension?

I'm excited to get started but I don't want to make rookie mistakes by moving to quickly. Please let me know your thoughts!

[Funkenstein]

yeah, first order of business is a good old fashioned soap and water cleaning! But theres no doubt that rust is inside that tank given the underside of the filler cap. Let's just hope that the rust has eaten pinholes into the floor plates or behind the badges 

Hey calj737! Thanks for the response!! Do you mean clean with soap and water INSIDE the tank? To me, it just looks like old gas and dirt so I want to start with as gentle a method as possible. Thanks again!!