Topic: Carb Part on CB500K2, What to do?

[madmacks]

I'm trying to find a couple of parts for my CB500 carb, or get advice on how to make a replacement if parts aren't available. I'm looking for the gaskets that fit on the carb adjustment assemble (used to balance the carbs). I've seen them referred to as dust cover gaskets. They are the parts in red in the image below.

Anyway, I've found the whole assembly for about $65 each, but all I need are the gaskets. Anyone know if they are available separately, or have advice on making a set, or do I even need them at all? I'm thinking I can just cut some gasket material for each end and jigger up my own set, but I'd like actual replacement parts without spending a ton of money.

Any advice will be appreciated...thanks...

[Noel]

It's a little hard to tell from the diagram, but those look like bits that I have not had on my bike in years. I've never had any problems. I have read that their purpose is to cut down vibration. I don't know if that's the case or not.

[chickenman_26]

I'm trying to find a couple of parts for my CB500 carb, or get advice on how to make a replacement if parts aren't available. I'm looking for the gaskets that fit on the carb adjustment assemble (used to balance the carbs).
Any advice will be appreciated...thanks..

Those rubber dirt shields were never available separately. If you can't find good used ones, you can make your own using a gasket punch set and some old inner tube material or something similar. Cut 8 circles 5/16" OD, and punch 1/8" holes in the middle of each. Push one over each of the balls before assembling the ball into the joint. Another alternative might be to locate some thin rubber washers of the right size in a hardware store. BTW, smear a bit of silicone grease on the balls.

Stu

[madmacks]

Thanks to you both...I figured I'd need to make something up myself. These gasket parts on the #1 & #2 carbs are all torn up, but the #3 & #4 seem to be ok. I guess I'm to anal about these thing but it bothers me that they're different. I'll probably make up a set for all four and change them all over. I wouldn't be doing any of this except I just balanced the carbs (big plug for the Morgan CarbTune) and noticed that they were cracked and hanging there. I needed to pull the carb for other reasons and thought I'd change them out while the carbs are off the bike.

One additional question on using an old inner tub to make gaskets...will that material be ok with the heat that builds up around the carbs? I don't what hot rubber burning or dripping. I might just strip them all off and leave it alone, as they are only dust covers. But, I do think the help the linkages line up and not rattle around.

Thanks again.

[bryanj]

OK VERY early CB500 four book lists the following:-

16138-323-004 Plate A dust required 4
16139-323-004 Plate B dust required 2
16140-323-004 plate C dust required 2

God only knows why 3 numbers and they may well be long obsolete but tey Western Hills Honda, if anybody has them it will be them

[madmacks]

Wow! You must have some interesting stuff laying around to have those old part numbers. I checked with  Western Hill Honda (online) and they do show those numbers and it appears they may have them. I need to call and confirm (will do when they open the parts dept).

Do you know, or does your source doco say what the part numbers are for? It looks to me like there are 2 sets of left and right gaskets, so I think I'd need two of the last two part numbers. I don't see anything on the carb that needs "4" of any part like this. Maybe WHH will know when I call them.

I think I've got a Keihin Type 1 627B carb, but that may not matter as these parts are part of the mounting brackets and not actually part of the carb. Anyway, I'm amazed at what people on this site know about these older bikes.

I have a 73 CB350 twin and a 73 CB500K2 and wouldn't know what to do without this site and it's members.

THANKS!

[bryanj]

The picture is WAAAY to complicated to be certain but there are pictures of three carbs with parts and those are the numbers with the quantities from the numbers list, The 4th carb is just shown as a "shadow" drawing with no individual parts show so cant help any more than that.

The Parts Books "Find" came from the US and is the old thick paper parts catalogue for the 71 500; 73 550 and 74 750 but from CB750 to K4.

They show many parts not found in later publishings,  like all the individual "O" rings with sizes.

Western Hills on line list prices for all the numbers but it dont mean they got them or can get them

[dave500]

i deleted them from mine,theyre not a real good seal anyway.

[chickenman_26]

OK VERY early CB500 four book lists the following:-

16138-323-004 Plate A dust required 4
16139-323-004 Plate B dust required 2
16140-323-004 plate C dust required 2

God only knows why 3 numbers and they may well be long obsolete but tey Western Hills Honda, if anybody has them it will be them

Excellent! Speed Supplies also lists them with a price. But like you say, that doesn't mean they have them. Maybe Ohio Cycle? My parts guy told me they're considered part of the adjuster holder sets and aren't available separately, and the current fiche seems to agree with that. But even if they were in stock separately somewhere, they're going to be almost 40 years old. I think I'd go for making my own. The last time I bought ancient rubber parts, they trashed themselves within 6 months after I installed them. Madmacks, I wouldn't worry about the innertube material melting. There isn't nearly enough heat in that area to damage rubber. It's age combined with exposure to gasoline and other petroleum products that damages them.

Stu

[madmacks]

Thanks again for the info...

I think I'll cut a set of eight individual gaskets from the tube rubber (or find something from the local hardware store), pull off the other two so they all match and have the same friction level (more or less), and see what happens. If that doesn't work over time I'll just strip them all off and go naked...

Now, all I have to do is put it all back together, fix my electrical/ignition problem (waiting for parts to arrive right now), and get back on the road so I can give my Triumph a bit of a rest. Then I can re-restart the rebuild of my project 73 CB350 twin. So much fun, so little time...