1971 Honda CB500 Four K1: An attempt at resoration

[Red Fthr]

So I fell in love with early '70s motorcycles especially the Honda CB series. I just bought my first one and I want to restore it as much as I financially can (I'm a 23 year old undergrad waiting tables) meaning most of the work will be DIY. I'm looking for some "does and don'ts" as well as any helpful tips about this specific bike. The bike runs but isn't mechanically sound; here's what I want to do:

1. re-build carbs
2. new exhaust system once I figure out what's making it run hot--I've got some blue steel going on.
3. re gasket engine
4. and while I'm at it replace all bolts, nuts, screw, etc.
5. clean and re-chrome everything that's oxidizing or has slight rusting.
6. new chain
7. clean wheels and true wheels
8. if I can find someone who can--repaint tank and panels.

attached--it's the best photo I have so far.

Thanks, Red Fthr

 

[ffjmoore]

Thats a nice little 500 you have. Should be a fun project. This website is great and full of a lot of helpful people. Another great resource is the SOHC4 forum. Get a manual for your bike. they are online and will make things much easier. As for your list I reorganized it a little.

1. re-build carbs, have you done this before? Take your time and clean everything real well.
2.new chain very important. If the old one break you could do serious damage to your motor
3.clean wheels and true wheels 000 Steel wool
4. and while I'm at it replace all bolts, nuts, screw, etc. OK
5. clean and re-chrome everything that's oxidizing or has slight rusting. Re-chorming is $$$ use the steel wool as best you can
6. new exhaust system once I figure out what's making it run hot--I've got some blue steel going on. The blueing is likely from a lean condition. When you clean the carbs i would check for the stock size jets and change them back if they are not stock. Pipes arent too cheap either if those clean up ok.
7. if I can find someone who can--repaint tank and panels. Try a rubbing compound and buff it. If you paint use automotive paint. Rattle can will get ruined by spilled gas.
8. re gasket engine. Is it leaking a little? Dont worry about it. they all leak. wipe it down every now and then. How many miles on it? If you take it apart for gaskets you may as well do the timing chain and check the primary chain. Those can cause real problems and if you have the motor apart is a good thing to address them.

I guess what im trying to say is do the important stuff to make it safe and then ride it. Later when you have a little extra money address the other stuff.

 

[SeanGSUK]

Lovely place to start, good luck.

VERY IMPORTANT: If it isn't broke, don't fix it!

You can get away with a lot with these bikes. They were often over engineered.

Carb set-up and chain are definitely the priority, safety first, bling to follow. If it is running lean, it can hole the pistons, so I would prioritise that, cheap job that will make all the difference. Like ffjmoore says, take your time. Do carb one at a time, don't use sharp, or abrasive materials to clean internals. If you can stretch to getting them ultrasonically cleaned I would, but a soak in paraffin will losen off most of the crud which can then be cleaned off with a soft tooth brush. Don't use anything with ethanol in to clean them as it ruins rubber. Take photos as you strip it down.

Patience is the game with putting carbs together, get it right first time and you'll save a lot of headaches.

 

[swan]

Welcome aboard. As mentioned, buy the Honda factory parts and services manuals. Haynes and Clymer manuals are fair, often fall short on descriptions and at times have errors.

A few thoughts:

1. Replace your original brake line with a new stainless steel line. You will be amazed how much better your brake will work.
2, Consider new tires. they are really not very expensive, what is your life worth?
3.Rechroming will cost more than you paid for the bike. +1 to 0000 steel wool and Mother's Polish.
4.Your paint looks good from the image above. Wash, polish with rubbing and finishing compounds and then wax. If you do paint, try paint from http://www.vintagehondapaint.com/SITE/VINTAGEHONDAPAINT.html.
5. You should replace the gear and rear sprockets with your new chain.
6. A new seat cover can revitalize an old bike.

Have fun and keep the images coming!

 

[Red Fthr]

Thank you ffjmoore and everyone else. This is some good information to get started on. I will keep posting as I work on it. Thanks again guys, very helpful.

 

[Red Fthr]

@ SeanGSUK I've already ran into the "fix it til it's broke" problem haha The more I touch the bike the more other things that I'm not even working on seem to break. With that said I'm going to start on the carbs first and do the chain while it's just sittin. I think that should be a good start.

 

[andycafe]

Well the boy's have already given you the tech info so i'm just gonna add "Great photo" that's a moment in time pic right there "Happy"nice!
looking forward to seeing how this come's up, Andy.

 

[tete]

Im just about finish with my second Cb500F K2. First of all you have a kick ass color and looks like you really don't have much to go. It looks like its mostly there. I will say use honda Carb needles and jets. do not mess around with after market stuff. depending on how dedicated you are finding parts like fenders and original seat pan trim and tank trim will be expensive and difficult to source but fleabay and patience are your best tools. Also if you can find the parts with the original OEM stickers and labels is always a huge plus. The original pipes are expensive a complete set will run you $1000 from honda but often you can find a parts bike with a clean set up for half that.



T

 

[Red Fthr]

OK guys--

so I've managed to:

1. rip off the carbs
-clean them and adjust floats (as it was running lean and hot prior).
-Did a "bench sync" (this might be wear I went wrong)

When I got inside a couple of the floats were a bit low. I adjusted floats (using a regular caliper to measure) and put the carbs back on.

2. I'm now idling at about 5000 and getting some smoke out of the engine and pipes. After fiddling with the choke and after the bike was beyond warm the idle came down a bit and I rode it around the block.

3. When shifting gears I got no power and would bog out.

4. When spraying starter fluid around the boots the bike also bogged out.

5. I also noticed a little (very little) bit of gas coming out of the needle at the bottom of the float bowl on one of the carbs.

I've concluded that I've now set my floats too high and need to re-adjust them. I have an actual Honda cb500 float gauge coming in the mail. I think it's receiving too much gas and running rich and at times getting flooded? I don't know why that would make it idle high though. Maybe I synced them wrong or something?

 

[Red Fthr]

Here's a video of what I'm talking about. Also, I bought a new air filter (paper).

http://www.youtube.com/watch?v=_iUn6uUGZpg&feature=plcp

 

[jimmiejoe]

YOU MEET THE NICEST PEOPLE ON A HONDA
Is that exhaust system a stock one... look s like a Vance and Hines

 

[swan]

It sounds your issue with the carbs is mechanical (not put back together correctly or misaligned) not mixture related. Float height should not affect your idle speed and I suspect any of the following: your throttle cable is not re-installed correctly, your idle screw(s) is/are too high, you carb cutaway slides or needles are misaligned not allowing the slide to drop into proper idle position. Remove the filters and look at the slides inside the throttle as you turn the throttle. The slide should go up and come back down smoothly. when the throttle is off there should be approximately 3/16" gap on all carbs. You will need to turn your idle mixture screws from that point to achieve proper idle speed.

What do you mean by 'bench synch" ? Did you use a vacuum tube and meters while the bike was idling?

Again, the proper Honda factory service manual will eliminate many problems and you should learn the 'how" and "why" of cleaning, adjusting and synching your carbs.

I would pull them off one a time, clean them again and reassemble following the manual. Ensure they are done right, re-install with no leaks around the mounting boot and try again.

 

[Red Fthr]

I agree it's something mechanical.

My idle screw isn't touching so I can eliminate that as a problem. I'm assuming my slides are stuck too high and need to be adjusted with the idle mixture screws.

What I mean by "bench syncing" is using something thin (in my case a long razor blade) to measure the gap and achieve similar heights through adjusting idle mixture screws. It's not exact but it's close and will still need to be synced with vacuum sealed meters.

I'm going to go at it again tomorrow. I'll try to document my process as much as I can just in case I end up needing more help, but I think with this info I'll be able to achieve what I need to--until I can get the sync-o-meter from my friend. If I can bring the idle down to a proper RPM tomorrow, I'll consider the day a success.

 

[axeugene27]

I don't know how to guide you friend but that is a cool bike Looks exceptionally clean in the pic for a bike that age. get those carbs dialed in and i'm sure it will be cherry.

 

[Red Fthr]

Got the ideal down, after reassembling correctly.

 

[Red Fthr]

Wholly tits.

Just found my first ever post....I need to update.

Since this post I've:

Replaced Piston Rings
Installed New Valves
Replaced all gaskets and O-rings in the top end
Put on Drag Bars
Removed Gauges
Broke the Hard Line on the Front Brake (only using rear at the moment)
I've replaced many bolts and nuts
I've relaced & trued my wheels
Replaced Tires
Rebuilt the carbs
Installed new gearing (17 front, 37 back) & New Chain
I've removed mostly everything
Shorted the fender
Removed front fender

I still Need:

New Exhaust
New Seat (currently riding on a skate deck)
New Push Rode
And I'm still trying to get my carbs tuned just right. I replace one carb issue with another every time I touch the bike it seams

I also got a new job making slightly more dough, so I'm hoping I can play with my bike more in the future.

Still in college.

I really feel like I've missed some opportunities to share my learning experiences. Everyone on this forum has helped me a ton (get it?). Thank you
Pictures coming soon!

 

[Red Fthr]

Got some pretty cool pics during my weekend fun run to Savannah, GA.

 

[axeugene27]

I'd go with a different tail light/plate holder as you are signaling aliens currently and giving cops a reason to stop you.

 

[Red Fthr]

I couldn't agree more. The tail light setup is temporary.

 

[Red Fthr]

Since my last post, I replaced that hideous taillight setup but quickly ditched the new set up since I'm building a single cafe seat.

I'm currently redoing the front end; replacing gaiters with dust covers, adding clip ons, repacking/greasing steering stem bearings, consolidating controls into a few switches, ditching the old controls, and I've I got myself a Billet triple tree bridge. Also, during all this I simplified my wiring harness a little, which might of caused some problems:

Video of issues with starter switch HELP!!
http://youtu.be/HAd8tBcrup4

Thinking about doing knee and handlebar cut outs, but not sure yet.

Below is the current state of the bike.