Topic: Korvens Cb500 original restoration

[Korven]

There has been a few months since i actively read the threads here on the forum, although i have still been occupied with my fair share of Soch4s this summer. The bike is a -73 K1 Candy Gold. In my eyes, it looked kinda decent but once i laid my hands on it showed a worse condition that i thought. Ill let the pictures speak.







































So the far worst thing was the fork legs. i had to hammer them each for an hour to get them out, so much rust. So im told that Honda didnt Chrome the top of the legs. I think the bike has been parked outside for a while since alot of the chrome details is showing rust. Exhausts on right side are pretty beated. brake pedal was bent, pointscover damaged, must have been tipped over. The tank has been repainted but whoever did it have not removed the paint from inside the cap hence the damage. electrical system is cut and modified everywhere. the first thing i did was source a new oem one (have heard the chinese copies cause issues) i got the oem for the price of the copy. The rear fender has extra holes drilled, too bad it doesnt have any damage anywhere else. the rims were terrible (the one on the picture are the orginal rims from the yellow bike that has lesters) Gonna get new rear shocks. thinking of doing a custom rear end on my cafe so i can steal the rear fender. Need to clean everything up for powdercoat now.


The engine is already done, it has been sitting in plastic wrap for a year now, awaiting a frame worthy enough. I picked up a gastank still in the original box for my brother(its the rear one in the picture) you can see how its got a more gold color while mine is more yellow. perhaps if i can source some oem side covers i can buy it from him.







Now for some questions:

Have anyone used these Italian made Tarozzi fork stanchions? https://www.wemoto.com/bikes/honda/cb_500_four_k1/72/picture/fork_tube_-_stanchion_-_single

[Korven]

sorry for the bad focus

[RAFster122s]

Looked nice in the intro photos...but that is typical of many bikes which are not as they appear.
Ran when parked...

Good luck on your journey finishing up the repairs and restoration.
David

[SOHC4 Cafe Racer Fan]

All in all not too bad depending on the price you paid.  I've definitely seen worse.

[PeWe]

Good looking survivor!
I saw much worse CB500's the first half of the 80's!

[Korven]

The main harness was really cut up and such so i get myself a new oem one for the price of the aftermarket ones. i have heard people having problems with the copies. Did some cleaning up of the other electrical parts. The pins do look really neat after you clean up the copper oxidation and gunk left in the connectors. now for some questions. The phases that feed into the rectifier, im guessing it doesnt care about the order and since everything else is driven of dc it doesnt matter after that point either? i put it back the same way just in case. Is there really any diffrence between these old rectifiers and the one on a newer bike? other than the regulator/rectifier being one unit and perhaps being more effective?

[seanbarney41]

There is nothing wrong with the stocker.  Out of dozens of sohc4s I have owned, I have never had a rectifier or regulator that didn't work perfectly.  You don't have to search long to find dozens of threads here on failed new aftermarket units.

[Korven]

Most of the bike is a apart. made a poor atempt at a timelapse, battery on the camera died before i really did anything but heres for trying.

[Korven]

Yucky carburators. Everything pretty much stuck. i wonder if soaking them in gas disolves the stuff.

[rusty2078]

Personally, I'd start by soaking them in carburetor cleaner (just remove float bowls and slides first, if the slides aren't too gummed up), then pick up a cheap-ish ultrasonic cleaner (just got one online, great tool for this) and run through a heated 30 minute cycle...use cleaner mixed with water...I used Simple Green and it seems to work OK in this application. Then start to disassemble all the small bits, and repeat the process. I find this much simpler and more effective than trying to soak, use brass brushes, contact cleaner, etc.

[Korven]

The carburators were both helicoiled with different sizes. So i ended up using other bodies incase it would bother me later on.



Found these quite cheap aftermarket shocks, they look like a good match




Engine put into the frame first. Very good method I caught here on this forum.




New fork legs installed. The old pipes were really rusted. I found some cheap tubes at cruzimage but the shipping was insane so ended up buying at cms.



New bearings!


Had to put some washers to fit the shocks. I ended up paying them black to melt into with the frame.




Dyeing them yellow. They turned out great.





I had some problems with the spookes on the front wheel but I found that if you pull them out while tensioning them they found they seated themself decently.




Not sure if I'm satisfied with the rear wheel. I need to get the tire of again since I tore a hole in the tube. There where soapbubbles coming out of the spokes as I used that as lube hehe. I wanted to get the tire on to see how the chrome would look. It has some scratches so I'm not sure if i should rechrome it or not? I do want to get it running by Summer. Your honest thoughts?

[PeWe]

Biltema tire lube work really well. Enough for decades in the bucket.
The tube must have some air inside to get a round shape avoid pinching it rhe last bends.

Plenty of tire lube on both sides of tire and rim will make the tire to glide on really easy the last tire bending part.
I use 3 irons like these.
https://www.24mx.se/dackjarn-proworks-380-mm-svart#?list=loop54-search-results&pos=1

I did front tire a few days ago.

[Mark1976]

Mounting tires is an acquired skill, some tires go on wet and some go on dry (a touch of baby powder), if your not happy with the rim condition you currently have I'd suggest buying a replacement and using your current rim to practice with until your new one arrives.  Look up changing a motorcycle tire, theres plenty of tutorials on doing it as well as methods of doing it. I rarely use tire irons anymore and even when they're needed, i use the small plastic ones that are normally used for bike tires to finish the last one or two small pushes over the lip of the rim. No scratches or blemishes.

[PeWe]

Rich amount of the tire lube does not need violent need of tire irons. Hardest part is to remove the old tire. Used the white  plastic rim protections Biltema and MX24 sell.

I have learnt the hard way  last year when I began to change tire by myself due to a tire shop scratched and dented a rim. Had to wait long time for them to get tube in stock too.

I pinched 2 Michelin tubes after each other last year due to my stubbornness to not inflate tube a little I knew must be done before. I ignored my own knowledge and trusted my finger pushing tube away before use of iron. - This did not work. 3 tubes for a rear tire replacement $$. MX24 had sale on the tubes so I had and still have extra.

More lube let the tire to glide on the last 30 cm by 2 irons on each side bending and see how tire glide on, land inside rim edge.

My K2 got flat front tire last year. I investigated all reasons I could think of, found a 3cm long scratch mark on tube where the hole was. Must have been when I wrapped the tire on 1 year earlier, 3000km rolled with bike.
This might explain some guys use of thick walled tubes (4mm) that will survive the tire irons better.

I use much more lube after that.
Double rim strips too. Baby powder inside tire so tube will nit rub.

[Korven]

Nice with new carbs. They are sodablasted and then ultrasonic cleaned. I rebuilt them using aftermarket kits. Not sure if the Airscrew should be 2.5 Turns out or 1+1/4. I used the orignal throttle needles since ive heard that the aftermarket ones doesnt seal well. I also used the 78 main jet. The packs comes with a few extra oring, they seem to be replacements for the jets and ofcourse for the 4 for the fuel. Floats set to 22mm. Its nice to have a spare set to be able to look at. Now i just have to get a hold of those special sync washers. The were some on ebay but quite expensive for what they are. im gonna see if the CNC class at school can make some spares from stainless for me, they seem to be a replacement since they easily bend or break.




Progress so far. I mouted a new rear inner since mine was cracked. Gonna see if i cant mount the carburators today aswell as the airbox. Hopefully i can get some help to get the front wheel mounted on monday or so.

Here is another pick showing my side cover compared to the OEM tank show in the beginning. it aint gold enough. Got hold of a spare tank incase i wanna repaint. They paint on the ones i have may not be correct but it still seems sad to paint over it. Side covers i would buy new ones to paint since the old ones are brittle from age anyways. Brothers garage showing in the background, fancy.

[PeWe]

That bike will look really good when completed! Nice paint!
Ready to be ridden coming spring, April-May?

[Korven]

That bike will look really good when completed! Nice paint!
Ready to be ridden coming spring, April-May?

Hopefully i will have it running by next season. I did promise myself to not stress in the end of the build, that is something that i usually do and i often lose intrest because of that because it doesnt turn out like i want it too. I had a small thought about doing a small europe trip on in if i get it running, well see about that.




Carbs mounted and some of the airbox.


Even found some original spare fuses laying around.

[Korven]

Got the Frontwheel on now. really pleased with the result on the brakedisc. Scotchbrite!
Also im never trying to put on TL tires myself again, it doesnt seem to be worth the sweat. ugh.

[PeWe]

Look very good!

You get used to bend the tires!
These bikes will not burn front rubber that quick, around 3 rear tires on 1 front on my K6.

[Korven]

Some small progress.  Rearwheel in place along with some other misc stuff. I did have a battle with the spring for the side stand, i dont seem to be able to get enough leverage to get it in place, Cause i am suposed to mount it after the sidestand is in place?

[PeWe]

My sidestand on my CB750 was tricky first time for many years.
Finally I used a big screwdriver to bend the spring in place on the mounted stand.
Screwdriver around spring loop, end of screw driver on the peg the spring loop to land around.
I do not remember if easier when  folded up, I think so.

[Mark1976]

Its easier with it in the up position, a pair or old brake spring pliers is what ya really need.

[Korven]

Headlight like new now, only downside is that it aint a H4 lamp, those ive got plenty of.



Feeler gauges 0.4mm thick. i took one size thicker than the oem bracket hopefully they wont bend as easily now.

Restoring meters. Does anyone know how much oil that is needed, im guessing ill fill the cup all the way up? Not sure if i should use that 50,000 or 100,000 oil.

[Korven]

Small steps forward.





Apparently there are two types of clutch adjustscrews. one with inner diameter of 8.1 and one with 8.8. I had sadly had the wrong one.
Restored the coils with new fresh wire and protective hose.

[Korven]

I am about to finish up this restoration. its been a bit slow in the end. Just waiting for the fuel tap and some stickers to finish it up. It did start up real nice after a few revolutions. I got the Candy paint back and im real satisfied (i did save the old tank for a build later on) Notice in the speedopicture that i almost forgot to put on the needle, that would have been a drag. Im gonna get some better pictures once i got it on the road.