Author Topic: Saving Stinky: '73 CB500/4 (Read 6207 times)

Whizwaz · « **on:** June 06, 2011, 05:50:52 AM »

Going to start a build thread here to document "Saving Stinky". She will be a slow build, as she has sisters in the garage that are more for daily riding.
This poor old girl was passed around, but never really taken care of since her first owner. She suffered some melted wiring back in '86, and has sat since then. It looks to be repaired, but I'll need to track down the "WHY" it melted down in the first place.
She will need lots of work, but I am willing to take care of her since she is a rather complete survivor.
The major visible pieces missing are the headlight and front signals, as her previous owner had a Vetter fairing installed, and that has since gone by the way-side.
First goal is to hear the sound of that SOHC run, so a carb cleaning, valve adjustment, and a good oil change are first.
Once she's running, the front brake will get a complete overhaul so I can give it a test ride to check the transmission. Those are the goals before fall sets in.
Over the winter she'll get torn down for a frame painting, fork rebuild, tires, rear brakes, wheel bearings, head bearings and any other items deemed necessary to have a safe and reliable scoot to enjoy.

Whizwaz · « **Reply #1 on:** June 06, 2011, 06:04:08 AM »

Took the time to pull the carbs, and this is what I found. Not very pretty. Choke and slides are all stuck.
Researched using the following to clean them: Simple Green, Vinegar, Pine-sol and good old carb cleaner.
Vinegar can potentially pit the aluminum, so that's out.
The MSDS for Simple Green states to avoid prolonged contact with aluminum, so that's out.
I can't find much on Pine-sol, but it is water-based, so maybe not a great idea.
That leaves good old carb cleaner. I have lots of room outside in the driveway to provide fresh air, and I can buy gloves. I also know it works. I have Berrymans here to soak them in, but I may switch to the NAPA brand, which seems to get good reviews. Hopefully things loosen up and turn out decent, and I'll have a good set of carbs.
I also need to wash the airbox and boots to the airbox to remove the grime and "critter droppings" before assembly too. -- John

BTW: I know I need to buy the seal for the shifter shaft, as she's leaking into a drip pan right now.

Bob Wessner · « **Reply #2 on:** June 06, 2011, 06:49:41 AM »

I wouldn't rule out using Simple Green despite the warning on the label. If you left it in for days, or it was highly polished aluminum.. maybe. Attached are some before and after pics of carbs I cleaned with it. As I recall, I mixed 50/50 Simple Green and hot water and let them soak for several hours, then thoroughly rinsed them in hot water.

Syscrush · « **Reply #3 on:** June 06, 2011, 06:52:57 AM »

Wow. Good luck with those carbs. I'd suggest some time in an ultrasonic cleaner, too.

Greggo · « **Reply #4 on:** June 06, 2011, 07:22:26 AM »

Welcome to the forum!

Sweet looking project, I'll be staying tuned.

brandEn · « **Reply #5 on:** June 06, 2011, 08:08:36 AM »

I would take apart the rack and start soda blasting. Looks like a fun project though.

Whizwaz · « **Reply #6 on:** June 11, 2011, 10:16:59 AM »

OK. I have the first carb off (number four) and have it apart.
Being skeptical, I didn't take a photo of the float bowl before dumping it in Simple Green. I will get an after shot, along with a before of the next carb, as it really works!
The float was stuck, and it took some careful pressure to get the pin out. Am am still cleaning, but I think I can save this one easy enough.
My question is: Do I need to pull the butterfly on the choke to scrub the inside throat of the carb? I only want to rebuild these once, so I want to be as exacting as I can.

I'll add photos mid-week. I will say these are a lot easier to deal with than the Mikuni carbs on the 82 Yamaha I saved. -- John

japscrap · « **Reply #7 on:** June 13, 2011, 09:36:43 PM »

the 750 matic carbs are a good swap for the 500's carbs if you need to replace them.
this is what I'm doing on my '72 cb500-4 .
my carbs were in worse shape than yours are though.

Whizwaz · « **Reply #8 on:** June 14, 2011, 09:03:30 AM »

Slight stall in the rebuild. The O-rings are either hard as rocks, or disintegrating, as I take things apart.
The good news is I just won my auction to get a complete replacement set so I can swap them out as I rebuild.
The photos of the clean carb are of the #4 carb. The photo of the main body was before it was fully disassembled, but I had just dunked it and started to scrub the outside. The float bowl is almost done. I need to get the last little bit of varnish from around the drain opening, but needed to buy a small plastic brush bit for the rotary tool to finish it off.
Using Simple Green, 50/50 with water, warmed up in the microwave. I have a plastic handled/bristled brush and a modified acid brush I'm using for scrubbing. Process is dunk/soak for 10-minutes/scrub/repeat.
The dirty carb is the #3 carb for reference. They are all about the same condition, so I do have hope for them.
Loose on the rack the slides all work, which makes me really happy. It's the actuator on the rack that's frozen. I do have two stuck chokes to deal with. (Carb 2&3)
My hopes are to keep the parts I received as-is and not replace anything: just save what's there. (OK, I am going to do some updates to the electrical and ignition, but no one will see those changes

) If I find a carb that can't be saved, I'll try for a replacement. Knowing I can swap them all out for 750's is great to know, just in case.

Whizwaz · « **Reply #9 on:** June 14, 2011, 09:04:10 AM »

Photos of the float bowls.

Bankerdanny · « **Reply #10 on:** June 14, 2011, 12:27:41 PM »

I removed my choke butterflies, but I had to in order to separate the carbs on my '77.

paulh1282 · « **Reply #11 on:** June 14, 2011, 12:43:46 PM »

Wow I think Im going to have to try that with some of my parts...

Whizwaz · « **Reply #12 on:** June 18, 2011, 08:28:05 PM »

First carburetor is done. What I learned:
There is a hole in the main jet once it is cleaned.
The float will move freely if cleaned properly
The float should not hit the top-inside of the carb long before closing the valve
Bugs are not part of the outside of the carb
The o-rings are not rock hard when you replace them
A carb rebuild is easy if you have a good reference (this group) and an exploded diagram

Just seeing the previous float adjustment made me wonder how this poor old girl ran.

Syscrush · « **Reply #13 on:** June 20, 2011, 06:17:50 AM »

Quote from: Whizwaz on June 18, 2011, 08:28:05 PM

There is a hole in the main jet once it is cleaned.

Bugs are not part of the outside of the carb

A carb rebuild is easy if you have a good reference (this group) and an exploded diagram

Those are some VERY valuable pieces of information.

Whizwaz · « **Reply #14 on:** June 22, 2011, 02:42:21 PM »

Opened up the second carb (#3) for cleaning.
Same issues as the first (#4): Plugged jets, stuck float (it has potential to be close to the right height), generally dirty (outside) and full of varnish (inside). The new object to tackle is the choke is stuck.
Anyway, I dunked the body, float bowl and jets into good old Berryman's. I checked it a few times over an hour or so to watch the progress. Figured it would eat pretty much anything that wasn't metal. Well...
I am either really impressed with Simple Green, or my Berryman's is from a bad batch. My o-rings were still there. They are getting replaced, so no big deal, and I wanted to see how destructive this stuff is. The choke is still stuck, and the jets are still plugged. The only real difference I can see between Simple Green and Berryman's is that I didn't have to scrub the float bowl for the same result.
I have soaked the choke with WD-40, and it is now operable.
An evening of scrubbing and rebuilding and I'll be half-way done with the carb rebuild process. -- John

Whizwaz · « **Reply #15 on:** July 08, 2011, 12:35:50 PM »

Just a quick update: Three carburetors cleaned, as well as the rack/stay that had the shaft frozen in place.
Two carbs are installed back on the stay, and new tubing in place. The third is there as a temp placement so I don't lose it until I get the last carb done and everything back together.
Rebuilding these is pretty simple. The first one took what seemed like forever. The last one is sailing along smoothly. All four had so much varnish the floats wouldn't move, and all the jets were plugged as well. If you happen to be rebuilding a set of carbs that have been set aside in '86 with fuel in them, I highly recommend having a torch nearby to warm up the varnish (just a little heat is needed) so jets can be cleaned and the pin removed to get the float loose.
Once the last one is clean and in place, I'll add a new photo showing my nice clean carbs. They are not polished for show, just nice and clean to work correctly.
Next is to wash up the airbox pieces and put things on the intake side back together.
The next big project to tackle is the rust container that looks EXACTLY like a fuel tank.

The rest of the "Getting it Running" will be typical maintenance items. (Plugs, oil, points, valve check, etc.) -- John

Whizwaz · « **Reply #16 on:** July 13, 2011, 08:04:06 AM »

I have the carbs all cleaned up and ready for installation. New fuel line installed and ready to trim to length. (And a fuel filter or two.)
No soda blasting, but it did cross my mind a few times. Only one slow-speed jet was plugged so bad I couldn't get it cleared.
They are not polished, but suitably cleaned to operate correctly. Simple green and a lot of scrubbing. -- JP

Syscrush · « **Reply #17 on:** July 13, 2011, 09:34:47 AM »

Quote from: Whizwaz on July 13, 2011, 08:04:06 AM

I have the carbs all cleaned up and ready for installation. New fuel line installed and ready to trim to length. (And a fuel filter or two.)
No soda blasting, but it did cross my mind a few times. Only one slow-speed jet was plugged so bad I couldn't get it cleared.
They are not polished, but suitably cleaned to operate correctly. Simple green and a lot of scrubbing. -- JP

I'm very impressed with your scrubbing skillz!

mjstone · « **Reply #18 on:** July 13, 2011, 12:05:20 PM »

Good job! Are you planning on keeping the bike stock?

MJ

Whizwaz · « **Reply #19 on:** July 13, 2011, 01:13:59 PM »

Thanks for the great comments! I felt I spent a good deal of time on each one to get them cleaned. Sat on the deck in the evening with a cold one while the wife sat and chatted with me. A couple evenings per carb and for the carb stay was all it took. Clean solution for each carb, as it was black after each one, and a layer of gunk at the bottom of my small crock.
My goal is to keep it as close to stock as possible. There are so few items missing it would be a shame not to keep it stock. I will update the regulator/rectifier, maybe add an electronic ignition (Hondaman, Pamco or Dyna) but no changes to the outward appearance. Maybe someday find an original exhaust.
The frame has bare metal that needs attention. I found replacement decals at cbdecals.com for when I reassemble. The paint on the side covers and tank are decent but slightly faded, and there is a slight dent in the tank. She is 38 with 18,000+ miles, so unless I have a bad experience cleaning the tank I'll just leave things alone.

Thanks again -- John

Whizwaz · « **Reply #20 on:** July 15, 2011, 07:41:35 AM »

Why am I going to maintain the originality of Stinky? This is the contents the tool pouch.
The fuse holder was in the airbox lid though.

I also have the original owners manual, the shop manual, and the registrations and insurance cards from the previous owner.

Whizwaz · « **Reply #21 on:** August 11, 2011, 04:58:17 PM »

Had to take time off to prep the touring bike for vacation down in NC. Rode lots of twisty roads and had a great time, but now I need to get back to my little stinky bike.
Today was a short day of removing the tank, pulling the petcock and getting the old fuel out of the tank. I know I shouldn't, but I just rinsed it and got huge chunks of rust. I need to grab a handful of hardware to break the rest of the rust loose. It appears not to leak right now, but...
From there I'll make a small plate to cover the petcock opening, then start soaking it with "The Works" cleaner. Need to make sure I have some two-stroke oil and baking soda handy if the cleaner works.
Wish I could get a photo, but don't think it wouldn't turn out. This poor tank is pretty rusty, but since it's original, I want to try and save it first.
Just an addition: the smell is horrendous! Tank is in front of the garage door, but the entire garage smells of 25-year-old gasoline! -- John

Greggo · « **Reply #22 on:** August 14, 2011, 11:39:56 AM »

Quote from: Whizwaz on August 11, 2011, 04:58:17 PM

Had to take time off to prep the touring bike for vacation down in NC. Rode lots of twisty roads and had a great time, but now I need to get back to my little stinky bike.
Today was a short day of removing the tank, pulling the petcock and getting the old fuel out of the tank. I know I shouldn't, but I just rinsed it and got huge chunks of rust. I need to grab a handful of hardware to break the rest of the rust loose. It appears not to leak right now, but...
From there I'll make a small plate to cover the petcock opening, then start soaking it with "The Works" cleaner. Need to make sure I have some two-stroke oil and baking soda handy if the cleaner works.
Wish I could get a photo, but don't think it wouldn't turn out. This poor tank is pretty rusty, but since it's original, I want to try and save it first.
Just an addition: the smell is horrendous! Tank is in front of the garage door, but the entire garage smells of 25-year-old gasoline! -- John

Trust me when I tell you that 'The Works' will work, but it will EAT chrome. Keep it AWAY from the tank lid, wear gloves while using it, and try to keep it off the paint too.

Whizwaz · « **Reply #23 on:** August 15, 2011, 02:17:49 PM »

I think I'll get to it tomorrow. I figured I would wear gloves, since it is a form of acid. (And an apron to keep it off my clothes, maybe safety goggles too.) I have used it to clean the bathroom, and it too smells pretty toxic! A job best done outside.
I am concerned about getting it on the paint. My paint is not the best, but it is original. I would prefer to keep the original paint and clean it up, rather than go in for a paint job. I'll need to be really careful not to get any on the outside of the tank.
My other concern is finding pin holes everywhere after cleaning. I have got a lot of rust out so far, and I fear the tank isn't going to hold fuel too well once cleaned. I'll update once I have it cleaned and know the complete status.

Danno · « **Reply #24 on:** August 18, 2011, 10:06:51 PM »

I use EVAPO-RUST on my tanks you can get it from TSC or harbor freight I bought 2 gallons and dumped them in let it sit over night then put a piece of plastic over the filler and closed it up and turned it over let it sit over night again worked great not a spot of rust anywhere in the tank and it does not remove any metal (the plastic is to plug up the vent hole in the cap)

orange550 · « **Reply #25 on:** August 19, 2011, 03:32:43 PM »

Do you know the brand of pipes on it?

Whizwaz · « **Reply #26 on:** August 19, 2011, 07:26:42 PM »

Quote from: orange550 on August 19, 2011, 03:32:43 PM

Do you know the brand of pipes on it?

I wish I knew. The 2 and 4 exit one side, 1 and 3 the other. (not sure which is to the right or left without looking) it is a 4-into-2 system.
They have rather square bends at the engine and where they bend to go back. I need to post photos so someone can identify them.
I would like an original exhaust, but that is a "way in the future" thing unless a set shows up cheap.

BTW: Tank is still being ousted from the garage due to the smell. Need to block the petcock opening and start cleaning it.

Whizwaz · « **Reply #27 on:** August 23, 2011, 05:38:16 PM »

Quick update: Removed and blocked the opening for the petcock. Dumped a handful of nuts/bolts/washers and tossed them around to break loose the big chunks.
Filled with Works (2 bottles) and water. Not happy, I drained off about half the mix. Been slowly repositioning the tank and letting it soak. So far, it's turning out good. I will need to drain it and give it another 50/50 mix of Works to get the rest of the rust out. Very impressed with the results I am getting so far, considering the rusty mess I had.
Next is to order a new petcock. Rubber was stiff, and the screen has a hole in it. And fuel fliters too.

News:

Author Topic: Saving Stinky: '73 CB500/4 (Read 6207 times)

orange550