Topic: 71 cb500 project... let's see how this goes!

[denward17]

I’ve noticed some new carb setups from places like Speed Moto that’s pretty much a new bolt on setup. Of course if i already had a factory set I’d just rebuild and move on but since I don’t and would need to source a set would something like this make sense or is the general recommendation from all to stay factory?

Seems like I’m probably gonna be around 350 to 400 bucks to get a factory set and go through them so if there’s only been 200 bucks more I was curious if it would be a better option to consider. I’ll also do some searching on here for people discussing these.

There have been others that opted for a dual carb vs 4x setup. In the end, they all switched back to 4x. Tuning for a dual setup with foam pod filters just creates LOTS of headaches to get a smooth, well running bike. Can be done, but, you’re in for tortuous times if you choose that route.

“The most expensive bikes are free…” Or barn find relics where you only pay a couple of hundred bucks. It makes everything you need to buy to restore the bike expensive by comparison. You need to decide today, what is your goal with this bike? Fix it, make it run, enjoy it? Fix it, sell it? Keep it long term? All those options dictate your budget and elbow grease. Top condition, near factory “new” only sell for less than $5k. And it would need to be in near perfect condition to get that. Just bear that in mind as proceed.

I can attest to this.  I started my K8 back in September with no clear goal, paid $800 for it, and eventually spent about $6.5K.  And I didn't touch bottom end or have the gas tank/side covers re-painted.

Good luck with the build, if you take your time and enjoy the process it will be rewarding in itself, no matter the cost.

[dmccall1202]

I understand that. I got it to have something to work on over time, something to do. I’ll get it where it needs to be eventually.

[wolf550]

luckily you are in an area where spare parts are readily available
plus as you keep up on your project and those subscribed following you may be able to chime in on the parts and the advice needed to keep the cost low.
best place is the wanted section so post it up when in need

[dmccall1202]

I didn’t realize Honda put spare tools in the electrical panel for us lol 🤦‍♂️

[Mark1976]

Ok, that's a first....

[dmccall1202]

That’s what I’m saying Mark lol

Finally got my new key yesterday so I hooked up a jump box to see what would work and nothing. 30 seconds later I see this. I guess someone tried to bypass a fuse. Hopefully the wirings is okay and I won’t need a new harness but I’ll get fuses and check out the rest of this stuff beginning of the week.

[Mark1976]

   Don't get too carried away trying locate issues in the wiring,  just a methodical approach, there are so many things that could be problematic. I start up front and slowly work my way back, eliminating any issues as (if) they're found. Check all your grounding points, then take a look at the fuse block, if its not showing signs of being partially melted your in a good place, if it does you've got your work cut out for you. Old bikes and wiring issues and burnt out lights go hand in hand. Patience...you'll do fine.

[RAFster122s]

If the fuse block shows signs of melting, then it is best to eliminate it from future issues as it can be a huge pita to try to get problem free. HondaMan offers a replacement modern fuse block that eleminates this issue and being able to get fuses easily is helpful.
As you clean every connection a little dielectric grease is a good idea to help things from oxidizing.

[dmccall1202]

I’m getting completely nothing right now so I figured I’d start with checking the switch and where power is going first.

I grabbed a glass fuse and it’s not working in there well, fit wise, and still nothing power wise.

I appreciate the advice on the modern fuses and got with HondaMan per your advice. He’s got me in the right direction so that should be updated this week.

I don’t see anything that looks melted or anything else so I’ll get this new fuse in and start checking to see where power is and isn’t.

[HondaMan]

I figured I’d need to replace the rubber boots to make sure I have a hood seal but good catch on the o-rings below the manifold Cal. I wouldn’t have thought of that until I pulled the motor and went through it.

I’ve noticed some new carb setups from places like Speed Moto that’s pretty much a new bolt on setup. Of course if i already had a factory set I’d just rebuild and move on but since I don’t and would need to source a set would something like this make sense or is the general recommendation from all to stay factory?

Seems like I’m probably gonna be around 350 to 400 bucks to get a factory set and go through them so if there’s only been 200 bucks more I was curious if it would be a better option to consider. I’ll also do some searching on here for people discussing these.

Someone from the Netherlands just sent me his CB550 head and those same intake manifolds for major porting to make them try to work together a little better. There is so much volume in those intake manifolds that the carbs cannot respond well to engine speed changes below mid-throttle, making a real wimpy low-end performance with overly rich mixing. They are not simple to make work!

[dmccall1202]

I’m glad i ended up getting a stock set! You all pointed me in the right direction and for that, I’m thankful. The others seemed like an easier go but that’s not the case.

[dmccall1202]

Hey, hey! It’s getting real in here. I set the carbs (no fuel yet, tanks the weekend project) checked all the connections,  loosened and resecured all the items at the panel and replaced the old glass main fuse with a modern ATC fuse per you guy’s recommendation and I’ve got power!

Switch works, blinkers work, headlights work, power to the dashboard, horn works and it turns right over!

Doesn’t look like I have spark at the plugs so I’ll check power to the coils, etc but this is progress!

I’m ready to get this baby fired up.

[Stev-o]

Congrat on getting a CB500, I had one a few years ago, it was a fun project. Did you buy the eBay carbs from "The Claw"?

I'd get a new battery as you will need one at some point anyway, AGM is the way to go IMO. Then check for spark at your plugs, would also be wise to replace the spark plug caps as well [coils and wires on these bikes seem to last forever]

Good Luck!

[dmccall1202]

I did get them from eBay. The sellers site is mrccycle.com

I haven’t decided on what I’m removing/keeping/replacing electrical wise and what battery will best suit as I plan to get ride if the side covers (don’t have them anyway) and do a relocate of the electrical panel to under a seat etc but will keep that one in mind!

Cleaning the tank this weekend with the prep and etch method then stripping it down to prime so i can do body work at some point and have it painted.

[dmccall1202]

Quick question, I’ve had the prep and etch phosphoric acid in there about 21 hours, rotating the tank every which direction every couple of hours and shaking around commonly.

Everything inside looks shiny and nice but I do have the pits/rougher spots in the inside wall that were rust spots that don’t look like rust anymore.

Are these clean and good to be done and move forward or am I in need of more time?

These have been the same for more than half the time and have not changed. So far no leaks of any sort.

[Shtonecb500]

that tank is all set my dude.

[dmccall1202]

Okay guys, I neeeeeeed help!

I’ve read so many articles and one always seem to leave off something another has.

I’m cleaning my tank, as mentioned above.  Here is what I did:

1. Klein Strip metal prep phosphoric acid in the tank for 24 hours. It's all shiny.
2. Drained it and immediately rinsed the tank out with a hose, for 5 minutes-ish until all was clear.
3. Immediately began drying inside with the leaf blower first for a minute to get most of the water out then the blower dryer for a few more minutes. By the time I got done blow drying the water dripping out was light brown.
4. Put a quart of acetone in for a minute sloshing it around and it came out light brown.

 Planned on putting diesel in to slosh around to be done. Didn’t even get to the diesel in it for finishing. Looks like I have flash rusting when the phosphoric acid was supposed to prevent that. I put the phosphoric acid back in it for now.

What am I missing? In some threads, I read to put baking powder or soda in the tank after the acid to neutralize it. Other people have said that basically removes the phosphoric acid seal that keeps the tank from rusting. I’m at a loss.

As you can see in the pictures below, when I went to drain it, everything looked good, the next picture is the brown acetone, and now the tank looked like this before I put the acid back in it.

[calj737]

The underside of the top of tank probably still has rust. Evaporation of gas creates moisture on the underside which turns to rust.

Put the PrepNEtch back in, and put a bunch of golf balls in to displace the fluid so the fluid reaches the top of the filler neck. The. You know you will be full and treating all surfaces.

[dmccall1202]

I’ve been absent here but still working on the bike.

I was able to get the tank cleaned and ready to go.

I also stripped the tank and it’s primed and ready for body work then to be painted. Decided to go with Honda Sonic Grey Pearl for the tank and have everything for that now. Got a new cap as well as a new oem petcock but am still waiting on emblems.

I also chopped by front fender down and it’s primed ready to be painted black.

[dmccall1202]

I also fully disassembled the carbs I purchased, I know most of you prefer that not to be done, but they had been taken apart previously anyways. 

Every piece for the carbs were vapor blasted inside and out. Then the carbs were rebuilt and bench synched.

New oem fuel lines as well. Very nice 👊

[dmccall1202]

I knew I wanted to upgrade the ignition system from the get-go but once I got the carbs on and tried to fire it up, nothing. I had no spark.

I had already ordered an electronic ignition kit with high output coils, new plug wires, and new spark plugs. I went ahead and installed the new coils, plug, wires, and spark plugs, and cleaned the original point set up. Of course, I want to get it running before the electronic ignition is installed to make things simple on that end.

[dmccall1202]

I filled the carbs up with gas today, and boom! We are now running. 😃

https://youtube.com/shorts/5rd2ydSZWkA?feature=share

[Shtonecb500]

nice work.

[newday777]

I filled the carbs up with gas today, and boom! We are now running. 😃

https://youtube.com/shorts/5rd2ydSZWkA?feature=share

Sounds good 👍

[Stev-o]

I filled the carbs up with gas today, and boom! We are now running. 😃

https://youtube.com/shorts/5rd2ydSZWkA?feature=share

Great feeling, isnt it?!!