Topic: CB550 Carb question (Keihin 627B)

[TBarr]

So I foolishly left gas sitting in my carbs for a year and am now stuck trying to degunk them and get them back in working order, they seemed worse than when the bike sat in the past and have been stubborn to get crap out and all of the seals were shot needing to be replaced.

I order this kit form 4 into 1 (https://4into1.com/ultimate-carburetor-repair-kit-honda-cb550f-super-sport/) which was in retrospect possibly the wrong thing to do since the jets and needles are different (although they don't have a kit for the 550k that I could find).

The brass in my carbs is so badly crudded up and some of it got mildly damaged during removal that I'm tempted to use all the clean and shiny new brass that came in this set since it all fits into the carb bodies, but my question is: why not do this?

The parts on the carbs on the bike are:

Main-100
Slow-38
Needles- 272304
Needle valve- 18

Numbers on the rebuild kit are:

Main-98
Slow-38
Needle- D274
Needle Valve- 18


I don't see any numbers on the emulsifier tubes, but they look very similar to me.


My questions are: 

If I change the needle to the new needle and change the jet at the same time to the new jets, would that work out fine? How different are the carbs on this bike than the carbs on the Cb550F (other than the difference in the jets)?

Can I least use the new emulsifier tubes or are they sized to the specific needles?


Someone please talk me out of putting in the new brass if it's gonna make the bike run like crap... I'd hate to end up pulling the carbs apart again.

[Kenzo1979]

Letting things sit for 1 year should not be putting you in that big of a mess.  Many of us here have pulled carburetors off of bikes that haven’t ran for a decade or two and were still able to salvage and clean everything. 

You mentioned that some of the brass was damaged during cleaning. What methods are you using to clean everything? Carb cleaner spray alone can take care of most of the work. It’s usually the passageways that need a good soak if things get too gunky.

As far as whether or not you can use the brass that you bought or not, I would say take a good look at those needles are they in fact the same? If the taper is different, things are probably going to be off. Not sure if you’ll be able to tune it in properly.  It’s really hard to say if the kits you got are any good or not. That’s why most people recommend just trying to keep the original brass.  Too much aftermarket stuff out there that just doesn’t match up. If you need to get good replacements, try partzilla or jetsrus for quality keihin replacements.  Best to do it right while you have everything apart.


Sent from my iPhone using Tapatalk

[Kenzo1979]

I just clicked on the link that you posted for the kits.  550F carbs were different than the 627b carbs.  you need kits for a  500K.  Which are fine to use on a 550 K 74 through 76, but the jetting is slightly different for the 627B.  What is the year and model of your bike? If you’re using 627B carbs it’s gotta be a 500 or 550 K before 77 I would imagine.  Start by getting the right kits for that model carburetor.


Sent from my iPhone using Tapatalk

[Kenzo1979]

This is the kit for the 627B from 4into1, but again, I cannot attest to the accuracy or quality.


https://4into1.com/ultimate-carburetor-repair-kit-honda-cb500k-1971-1973/


Sent from my iPhone using Tapatalk

[TBarr]

This is the kit for the 627B from 4into1, but again, I cannot attest to the accuracy or quality.


https://4into1.com/ultimate-carburetor-repair-kit-honda-cb500k-1971-1973/


Sent from my iPhone using Tapatalk

I didn't realize this kit would work on the carbs that I have or I would have just purchased that kit. Their website doesn't mention that it's the right kit.
The jets and all the parts I have in this kit physically fit in the carbs,  but I just don't understand how much difference a 98 main vs a 100 main jet coupled with a different needle will really make in the operation of the bike.

The bike sat with fuel in it, hence the gunking.

The brass hasn't been messed up by cleaning it so much as removing it from the carbs. Some of the jets have just minor scratches on the outside that probably won't impact the function much I would imagine, but it has been a bear to get all of the green gunk that has accumulated. Carb cleaner and letting it sit in carb cleaner isn't cutting it. I will have to polish them all up with some steel wool to get them looking clean again if I'm going to reuse them.

Can anyone answer the questions about the effect of using the 98 main jet and this needle in these carbs? How about with using the new emulsifiers with the old needles?

[Kenzo1979]

Had to go into your old posts to see what bike you have.  I remember you now.  74 550K motor on a 72 500K Frame with 500K carbs.  You say the 4into1 website didn’t say the kit was for your carbs, but the kit you bought doesn’t either, so I’m confused on why you got that kit.  The 550F had a different setup than the K’s.  I’m sure stuff looks the same and possibly fits the same, but it’s probably going to have you constantly chasing fuel/air mixture and performance issues if you’re looking to just put them in.  Hopefully you get the answers you’re looking for, but I believe you will have to get the correct pieces or reuse the originals to make things work right.  Also I hope you’re using the stock airbox set up. The more information you give about your entire setup, the better people will be able to steer you right.  Good luck!


Sent from my iPhone using Tapatalk

[TBarr]

Yea that's the correct confirmation of the bike, thanks for taking the time to help steer me in the right direction.

I think I just looked at the picture of the parts and saw it was the 550 from the right year of my bike and figured the kit would work, and I think the kit will work if I just take the time to clean up all of the old jets and put new seals on them.

I guess I was just hoping somebody on here would tell me to just use the new stuff and it would work fine to save me the time of trying to salvage the old parts...

Does anyone know if at least the emulsifiers will work??

[Deltarider]

Letting things sit for 1 year should not be putting you in that big of a mess. 

I agree. We know US gas has no extra proporties to speak of and ranks among the lowest third world quality found elsewhere. The same goes for overviews of carb data you see surface every now and then, which have in common that they are blindly copied. I've composed an overview of the oldstyle carbs on the CB500/550s that may help you. If any wants to falsify my findings, please do. I welcome that.
I cannot comment on aftermarket parts, as I have no experience with them. My advice in general is: stick to OEM parts. I don't know about other carbs but the Keihin brassware in these carbs: 627B, 649A, 022A, 087A and 069A hardly wears. In almost 140.000 km I have not detected any wear at all.

[TBarr]

Letting things sit for 1 year should not be putting you in that big of a mess. 

I agree. We know US gas has no extra proporties to speak of and ranks among the lowest third world quality found elsewhere. The same goes for overviews of carb data you see surface every now and then, which have in common that they are blindly copied. I've composed an overview of the oldstyle carbs on the CB500/550s that may help you. If any wants to falsify my findings, please do. I welcome that.
I cannot comment on aftermarket parts, as I have no experience with them. My advice in general is: stick to OEM parts. I don't know about other carbs but the Keihin brassware in these carbs: 627B, 649A, 022A, 087A and 069A hardly wears. In almost 140.000 km I have not detected any wear at all.

Thanks for the useful information. That chart is basically what I've been looking for but haven't been able to find.

I guess my bike doesn't exactly fit into the standard scheme since it's a 550k engine but with 627B carbs which according to the chart were not put on the 550k.

However, I do have already the size 38 slow jet which according to this chart would go with a 550k engine, but with the "022A" carbs.
These carbs are also using the original needles that I have (272304).

It seems the prevailing opinion here is the just take the time to clean up the old brass that was in the carbs (I'm not 100% sure it's original since I'm not the original owner of the bike). Which I don't mind taking the time to do if it is going to lead to fewer headaches down the road.

My question now would be- your chart says the needle position on the 550k should be the 4th position. Mine were in the 3rd position when I took them out, but my carbs also appear to have come off of a 500 engine. Should I move the needles to the 4th position now?

Also- does anyone know if the emulsifier tubes are interchangeable between the 550k and 550f or are they different?

I've got to wonder how different these various carb models are on the inside? They look the same on the outside to me and the parts are all interchangeable. I guess they just did this for manufacturing and ease of servicing reasons but they made tiny changes to interworkings of the carbs that affect which jets/needles are best for that specific model of carb?

[BomberMann650]

Berrymans Chem-Dip restores brass parts - crud and oxidation just dissolve in the solution.  They come out looking fresh from the assembly line.
Albeit, chem-dip can't repair tool marks

Aside from the jetting and model number.  The 627b is cross compatible with their 069a and 022a predecessors

[Bankerdanny]

Can you post pictures of the damage to your brass? Letting gas sit in the carbs can be really bad for the jet holder tubes as the aluminum can get eaten away by the ethanol in the fuel. But, that usually requires multiple years of sitting, not just one.

It would be helpful if you would add the details of your bike in your signature. Since you have a Frankenbike it is almost impossible for us to answer your questions on a subject like this because we don't know important details like the year of your engine and the model carbs you have.

[TBarr]

Can you post pictures of the damage to your brass? Letting gas sit in the carbs can be really bad for the jet holder tubes as the aluminum can get eaten away by the ethanol in the fuel. But, that usually requires multiple years of sitting, not just one.

It would be helpful if you would add the details of your bike in your signature. Since you have a Frankenbike it is almost impossible for us to answer your questions on a subject like this because we don't know important details like the year of your engine and the model carbs you have.

That's a good idea to put that in my signature here.

From the comments here and to clarify though, this is a 550k engine with 627B carbs. The engine is mounted to a '71 frame not that it really matters for the sake of the questions here.

I did notice the jet holder tubes getting a little eaten away but I wouldn't think it would be enough to affect their function.

I already reassembled the bike and took it on a brief test ride. I used the following parts:
Main jets- 100 (original)
Needles-27304 (original)
Needle position- 4th from top
Slow jet- 38 (new parts as it was the same number jet)
Needle valve and needles- New parts (same numbers and apparent function as original)

I did have to adjust all of the floats slightly to get them to 22 with the new valve needles being a little shorter than the original and in retrospect, it may have been easier to just use original parts here as well.

The damage to the brass was basically just some scratches from tools struggling to get them out of the severely junked-up carbs.

I got off most of the crap that was on them that wouldn't come off with carb cleaner with a light touch-up with steel wool.

The bike now runs which of course it wouldn't do with carbs that were completely junked up. It remains to be seen how great it's running but hopefully now will be running at least as well as it did before it sat for a year.

While assembling I noticed a little oil on the outside of the engine, I will start a different post to address that...

[TBarr]

Photo to give you an idea of the condition of some of the brass before I touched it up today.

[Kenzo1979]

Now the question is, are the existing brass parts in fact original or were they from an aftermarket kit from a PO?  Only reason I ask is because the 627B called for a #40 slow jet.  Not sure how much that will effect anything, may be as simple as adjusting your idle screw.  And I feel like I’ve read different posts where people claim to have #38 in their 500 carbs and some claim to have #40 in their 550 carbs. Look for the Keihin “K” logo on the parts.  Good to hear it’s running.  Now to tackle that oil leak.  How long did you say this sat?  Any previous engine tinkering?  Maybe from a recent PO?  When did you acquire this bike and is there any history of servicing, mods, etc.?  Don’t hold back info; lay it all out there and you’ll get faster resolutions. 


Sent from my iPhone using Tapatalk

[Deltarider]

My question now would be- your chart says the needle position on the 550k should be the 4th position. Mine were in the 3rd position when I took them out, but my carbs also appear to have come off of a 500 engine. Should I move the needles to the 4th position now?

First of all: this is very interesting if the CB500 was a US model. I have always mistrusted the data in that US booklet (edited in 1977!). There's no mentioning of having the needle in 4^th position on a CB500 in Honda documents, except that US booklet which also suggests to have the airscrew two turns out instead of the standard one turn, elsewhere in the world. The reason I mistrust this booklet is that the jet needle (-323- !) has been first designed for the CB500 and so it would be logic if Honda wanted it to have in the middle position, the same postion the rest of the world had it. Could that 4^th position in combination with the 2 turns out of the airscrew have been recommended especially for CA, where emission legislation initially concentrated on a less poluting idle? Anyway, I'd suggest to have everything in the position, the chart suggests, provided the air intake is original.

Also- does anyone know if the emulsifier tubes are interchangeable between the 550k and 550f or are they different?

I'm afraid they're different. The OEM needles have a different number stamped in: 272304 x 273004.

I've got to wonder how different these various carb models are on the inside? They look the same on the outside to me and the parts are all interchangeable. I guess they just did this for manufacturing and ease of servicing reasons but they made tiny changes to interworkings of the carbs that affect which jets/needles are best for that specific model of carb?

Until we learn something new, we (internationally) assume the carbs are the same, but for the jetting. So far we have no indication the venturi differ.

[TBarr]

My question now would be- your chart says the needle position on the 550k should be the 4th position. Mine were in the 3rd position when I took them out, but my carbs also appear to have come off of a 500 engine. Should I move the needles to the 4th position now?

First of all: this is very interesting if the CB500 was a US model. I have always mistrusted the data in that US booklet (edited in 1977!). There's no mentioning of having the needle in 4^th position on a CB500 in Honda documents, except that US booklet which also suggests to have the airscrew two turns out instead of the standard one turn, elsewhere in the world. The reason I mistrust this booklet is that the jet needle (-323- !) has been first designed for the CB500 and so it would be logic if Honda wanted it to have in the middle position, the same postion the rest of the world had it. Could that 4^th position in combination with the 2 turns out of the airscrew have been recommended especially for CA, where emission legislation initially concentrated on a less poluting idle? Anyway, I'd suggest to have everything in the position, the chart suggests, provided the air intake is original.

Also- does anyone know if the emulsifier tubes are interchangeable between the 550k and 550f or are they different?

I'm afraid they're different. The OEM needles have a different number stamped in: 272304 x 273004.

I've got to wonder how different these various carb models are on the inside? They look the same on the outside to me and the parts are all interchangeable. I guess they just did this for manufacturing and ease of servicing reasons but they made tiny changes to interworkings of the carbs that affect which jets/needles are best for that specific model of carb?

Until we learn something new, we (internationally) assume the carbs are the same, but for the jetting. So far we have no indication the venturi differ.

Interesting to hear that the carbs are the same aside from jetting.
So what else was different about the 550k vs the 550f aside from the jetting in the carbs? I assume the actual engine or tranny had some differences? Different exhaust?

My bike has a 4 into 2 exhaust.

[TBarr]

Now the question is, are the existing brass parts in fact original or were they from an aftermarket kit from a PO?  Only reason I ask is because the 627B called for a #40 slow jet.  Not sure how much that will effect anything, may be as simple as adjusting your idle screw.  And I feel like I’ve read different posts where people claim to have #38 in their 500 carbs and some claim to have #40 in their 550 carbs. Look for the Keihin “K” logo on the parts.  Good to hear it’s running.  Now to tackle that oil leak.  How long did you say this sat?  Any previous engine tinkering?  Maybe from a recent PO?  When did you acquire this bike and is there any history of servicing, mods, etc.?  Don’t hold back info; lay it all out there and you’ll get faster resolutions. 


Sent from my iPhone using Tapatalk

I think I remember seeing the little K on some of the brass but that is a great question. The guy that sold it to me waaaay back in 2007 gave me some extra parts and I think there were some bits from a carb rebuild kit so it's definitely possible there is non-original brass in the carbs.

The carbs are all back together and on the bike (damn it is a bear to get them back on there!). I put new boots on both sides of the carbs as well with original airbox.

I've had this bike now for about 15 years and I've spent more time tinkering with it than riding it I'm quite sure. It's been neglected quite a bit over the past 10 years as I've been going through medical training I haven't had a lot of time to mess with it.

This last time the bike sat for almost exactly one year.

Things I've done recently to the bike recently include: compression test (normal), replace points, recheck timing- needed no adjusting, readjust valves, replaced coils/wires, replaced plugs and as described here I rebuilt the carbs now again after letting it sit this past year. I also put some new fuel line in when reinstalling the carbs.

I have also replaced the fork seals and the front bearings. I had a shop do the brakes for me and put on new shocks on the rear. I was having some issues with the fork and they told me the fender was bent causing that issue so they recommended replacing or removing the fender, so now it has no front fender.

Way back when I first was working on the bike I put on some aftermarket handlebars that I thought looked cool. I kinda regret that but the old bars are long lost now and I don't think I want to mess with it anymore.

Whoever changed the engine out in this bike's lifetime did a piss poor job on the electrics and the bike has had some electrical issues, but everything seems to work now. I did buy a complete replacement wiring harness considering redoing all the wiring but I'm not sure it will be worth the time messing with it. My only concerns are that they bypassed all the fuses!

The next little project is to put on a new petcock, I busted a pipe off on the old one so now it leaks slightly and I'm not sure it was flowing right in the first place so I think I'll just replace it.

Is that enough info?

[Kenzo1979]

Wow, there’s definitely some interesting information in there. First, I don’t see how a bent fender would mess with the forks to the point where you couldn’t just bend the fender back into place to remedy the situation. Without a front fender, you would need a fork brace.  I mean I’m sure you could putt around locally without one, but I wouldn’t trust high speeds without some type of brace or stock front fender (which includes an integrated brace) for the forks. 

Broken pipe on the petcock? Which type of petcock and tank do you have? The type of petcock that gets bolted onto the tank with two screws or the type of petcock that you thread onto a threaded nipple on the tank?

And as for the electrical stuff. You definitely do not want to be bypassing fuses. Put that new wire harness on and save yourself a ton of headaches. If the PO did a hack job on the existing harness, I guarantee you’re gonna be chasing some gremlins down the road.


Sent from my iPhone using Tapatalk

[TBarr]

Wow, there’s definitely some interesting information in there. First, I don’t see how a bent fender would mess with the forks to the point where you couldn’t just bend the fender back into place to remedy the situation. Without a front fender, you would need a fork brace.  I mean I’m sure you could putt around locally without one, but I wouldn’t trust high speeds without some type of brace or stock front fender (which includes an integrated brace) for the forks. 

Broken pipe on the petcock? Which type of petcock and tank do you have? The type of petcock that gets bolted onto the tank with two screws or the type of petcock that you thread onto a threaded nipple on the tank?

And as for the electrical stuff. You definitely do not want to be bypassing fuses. Put that new wire harness on and save yourself a ton of headaches. If the PO did a hack job on the existing harness, I guarantee you’re gonna be chasing some gremlins down the road.


Sent from my iPhone using Tapatalk

Hmm, that is concerning to hear that the front fender is structurally needed for the bike...The guy at the shop told me there was no need to leave it on as he was the one who suggested removing it. I'm starting to think maybe this guy doesn't really know these bikes that well.

The old fender is pretty badly bent, it was keeping the forks from moving up and down easily.

I have the kind of petcock pictured here- one of the little fuel outlet pipes came off while pulling on some old fuel line during the carb project... I jammed it back in there but now it has a small leak to it.

[Stev-o]

Wow, there’s definitely some interesting information in there.

Hmm, that is concerning to hear that the front fender is structurally needed for the bike...

I have the kind of petcock pictured here- one of the little fuel outlet pipes came off while pulling on some old fuel line during the carb project... I jammed it back in there but now it has a small leak to it.

I wouldnt go as far as saying it is "structurally" needed, but it does offer stability to the front end.
When I restored my K3 "Park Racer", I didnt want a front fender but installed a fork brace in place for stability.

It is fairly common to have the brass part come out of the petcock as I believe they are just pressed in. A gas resistant sealer [All Seal?] may solve that issue.

[Kenzo1979]

I don’t see how the fender could effect the movement of the forks.  The fork tubes move in and out of the lower fork leg.  The fender (braced) is attached to the lower fork legs.  So that should have no effect on their movement at all.




Sent from my iPhone using Tapatalk

[Kenzo1979]

Also, I had the nipple of my petcock pull out before as well.  And now I remember posting on another thread of yours about it.  As Stev-o said, they are just press fit.  But before you put any sealants in, try to flare the end that goes into the petcock a little with something tapered like a nail set, small punch, etc.  first…just enough to give it a tighter fit as you press or tap it back in.  I’ve done this, it works. I do not have a leak on the nipple I pressed back in.


Sent from my iPhone using Tapatalk

[TBarr]

I don’t see how the fender could effect the movement of the forks.  The fork tubes move in and out of the lower fork leg.  The fender (braced) is attached to the lower fork legs.  So that should have no effect on their movement at all.




Sent from my iPhone using Tapatalk

I was surprised to hear that the bent fender was causing an issue with the function of the forks as well, but it made sense to me after he explained it. The fender was bent so it was causing the forks to be misaligned and therefore not operate smoothly.

Plus once the fender was off the forks move up and down fine, so the proof is in the pudding that it was causing the issue.

[Kenzo1979]

Ok, I guess I can understand that.  But I find that brace to be comforting.  You can probably find another fender from a member or on eBay, etc. pretty easily if you want it on there.  I also like the way it holds my speedo cable and brake line.


Sent from my iPhone using Tapatalk

[TBarr]

Ok, I guess I can understand that.  But I find that brace to be comforting.  You can probably find another fender from a member or on eBay, etc. pretty easily if you want it on there.  I also like the way it holds my speedo cable and brake line.


Sent from my iPhone using Tapatalk

Yea, honestly I would kind of like to have the fender back on it especially if it's important for the 'stability' of the bike at higher speeds...

There are about $160 for reproduction fender on eBay plus 80 for shipping. Not sure that is worth it for me or not. I could try to straighten out the old one I guess or look for one of these so-called fork braces?

I had to zip tie the brake line in lieu of the fender holding it, not an ideal solution.

[Kenzo1979]

Oh and back to the wire harness… is it a 500 wire harness?  You claim your bike is a 500 with a 550 engine, but is anything else 550’d besides the engine…handle bar controls, front turn signals (dual element-riding lights), the electrical panel itself?  If so, there were differences that could impact the harness.


Sent from my iPhone using Tapatalk

[Kenzo1979]

Ok, I guess I can understand that.  But I find that brace to be comforting.  You can probably find another fender from a member or on eBay, etc. pretty easily if you want it on there.  I also like the way it holds my speedo cable and brake line.


Sent from my iPhone using Tapatalk

Yea, honestly I would kind of like to have the fender back on it especially if it's important for the 'stability' of the bike at higher speeds...

There are about $160 for reproduction fender on eBay plus 80 for shipping. Not sure that is worth it for me or not. I could try to straighten out the old one I guess or look for one of these so-called fork braces?

I had to zip tie the brake line in lieu of the fender holding it, not an ideal solution.

Start a post on the “parts wanted” section.  Even if people don’t have what you’re looking for, you’ll find members to be very helpful in trying to point you in the right direction.


Sent from my iPhone using Tapatalk

[TBarr]

Oh and back to the wire harness… is it a 500 wire harness?  You claim your bike is a 500 with a 550 engine, but is anything else 550’d besides the engine…handle bar controls, front turn signals (dual element-riding lights), the electrical panel itself?  If so, there were differences that could impact the harness.


Sent from my iPhone using Tapatalk

I bought the harness for the 500. As far as I can tell they didn't change much else, but I'm not 100% sure about the electrical panel, the panel like I said was largely bypassed in the wiring job they did, so I would be surprised if it was replaced. The handlebar controls are definitely from a 500 as I replaced the original with an aftermarket 500 kit since they were busted. I have no front turn signals (wouldn't mind adding some at some point).

[Kenzo1979]

Can you post a picture of your electrical panel?


Sent from my iPhone using Tapatalk

[amitr0]

This is the kit for the 627B from 4into1, but again, I cannot attest to the accuracy or quality.


https://4into1.com/ultimate-carburetor-repair-kit-honda-cb500k-1971-1973/


Sent from my iPhone using Tapatalk

For what it matters, I have a '56 550K, US model almost all stock, and recently tried overhauling the carbs for the same reason as OP. I got the corresponding kit from 4into1 and the first thing I noticed was that the drain screw didn't fit the bowls.

This is the second time I go something from 4into1 and it didn't fit my stock bike, the other time was about engine casing bolts, none of them were even the right sizes, and then i went back and checked, in the fine print they had written 'some of these might not fit your motorcycle' in the posting itself.

I don't think I will give 4into1 a third chance after these two encounters.

Lessons learnt : Not to throw away anything before actually installing the aftermarket replacements, no matter how badly damaged they look.

[TBarr]

Can you post a picture of your electrical panel?


Sent from my iPhone using Tapatalk

[Kenzo1979]

Well that’s a 550 panel.  Pretty sure none of the 500’s had the 3 fuse setup.  Just 1 inline 15A fuse under a plastic barrel enclosure.  Not that they were extremely different, but there can be some differences. I honestly can’t tell from the picture what would be different though.


Sent from my iPhone using Tapatalk

[TBarr]

Well that’s a 550 panel.  Pretty sure none of the 500’s had the 3 fuse setup.  Just 1 inline 15A fuse under a plastic barrel enclosure.  Not that they were extremely different, but there can be some differences. I honestly can’t tell from the picture what would be different though.


Sent from my iPhone using Tapatalk

Interesting, I wonder why they put it on but didn't really wire it up...

It seems like fixing the wiring is gonna be a pretty big pain. Redoing everything will likely take me a couple of days if not more if I run into issues with compatibility. Is there some type of quick fix maybe that I can put in a fuse or two in the circuit for safety sake?

[bryanj]

It has a very cheap cicular flasher can hanging below the rubber the " us normal" rectangular one fits and i think the original type starter safety circuit box is what should be above the fuse box which is missing its lid.
The 500 only ever had a single fuse

[Kenzo1979]

Yeah, for basic protection splice a 15A fuse in the red wire going from Battery Positive to the Electrical Panel Connector that feeds the Ignition Key Switch. 

Check the wiring diagram:

http://manuals.sohc4.net/cb500/technical_reference/WD500C.pdf


Sent from my iPhone using Tapatalk