Start of a 1963 CB77 rebuild

[Inty]

I've owned my 1963 CB77 for about 6 years I think, but I only rode it a few times right after purchase. Mileage on the odometer is 17,559, which is believable. I bought the bike on the south shore of Massachusetts (Rehoboth), brought it up to the Boston area, and now it's with me in Indianapolis.

When the bike was last running, the left cylinder would idle weakly, one of the carb slides would stick in the open position, and the clutch lever was extremely difficult to pull. Also, one day while attempting to kick start the engine, I heard a pop and the kickstarter would not engage after that. I remember having a hard time feeling as though the chain adjusters were set properly. Perhaps I was overzealous in tightening them as I bent one pair and had to buy another pair. Even with the new pair, I didn't feel as thought the axle was perpendicular to the axis of the frame.

My bike is nearly complete, but after 45 years, things are bound to be changed and/or missing. There are a few incorrect replacement fasteners, the front fender is bobbed, the final drive chain guard is missing, a front fork ring is missing, the rear shocks appear to be aftermarket, the lower shock mounts are aluminum fold-out foot pegs, the exhaust is not original, the seat pan is rusted with one of the mounts broken/missing, and the handlebars are modern motocross style. The brake shoes have the HM logo and are in great condition.

The bike appears to have been dropped at some point as 4-5 cooling fins on the left side of the engine are broken off, the clutch shift pedal is bent and scraped, as is the broke pedal. When I had the left side engine cover off at one point to check the clutch, I had a hard time getting the case back together as the clutch shift spindle also appears to be untrue.

I bought a new set of tires from Michael Stoic some years back (I remember meeting him in the Assembly Square Home Depot parking lot in Watertown, MA), replaced the spark plugs, replaced the final drive chain and sprockets, and I repainted the tank, fenders, and side covers with spray can lacquer for the fun of it, so the paint job is not that great. I also have new wheels and spokes from eBay that I have never taken out of the box other than to look at them. I don't mind the bike having incorrect parts as long as the whole package looks good and runs reliably.

I plan to remove the engine from the bike in the next month or so and bring it into the basement where I can work on it a little more comfortably. The initial list of things that I know need to be tackled include rebuilding the petcock, rebuilding the carbs, replacing cables, replacing air filters and air tubes, repairing the kick starter, and repairing/replacing the seat.

I will check the condition of the engine and make all proper adjustments, but I do not plan to rebuild the engine at this time, unless of course I receive vehement responses from you folks.

I have attached some pictures so you can see what I have to work with. I do have the dynamo cover, but I had removed it in the past for some reason of another.

I hope follow in FiremanBob's footsteps and provide period updates with photos. I look forward to your comments and suggestions!

Cheers!

[Inty]

Well, the wind is blowing pretty hard out there today, but it was over 50 degrees today, so I set myself up in the garage for a couple hours between wiring some light switches around the house and rearranging furniture.

I removed the exhaust pipes, carbs, and right side cover. The engine turned over easily with a wrench. I removed the tappet covers to have a look. Everything inside still smells of hydrocarbons. The oil still looks good. The carb air tubes and air filters are pretty much toast, but I knew that already.

I called it quits before disconnecting the starter and points wiring from the harness because I want to label each connection before disassembly. At least I now have the carbs off the bike so I can tear them down and give them a good soak before rebuilding.

What course of action do most folks take with the wiring harness? The wire wrap sheathing is cracked in many places and generally feels stiff and brittle. I didn't originally intend to replace the wiring harness, but if they aren't too spendy, I may consider it for peace of mind.

I probably won't get to removing the engine from the frame for a couple of more weekends. I'll be sure to take some pictures before I drop the engine.

Cheers!

[Inty]

I know it seems like I'm talking to myself here, but it's hard not to be excited at the start of a project like this, especially since I've been putting it off for so long.

I got into the carbs a little bit tonight and snapped some pictures. The left side throttle valve (slide) is the one that was sticking. There was some oily-varnishy buildup on the slide that seems to be at least part of the problem. The left slide also shows a lot more wear than the right slide. The left slide has a lot of brassy color, while the right slide is still mostly shiny with just some brassy color showing through around the edges.

I'm also fairly confident that the slides were installed on the wrong sides. The slanted part of the slide was facing towards the engine. If that wasn't enough, the inscribed markings 20* PW26L and 20* PW26R on the tops of the slides were in the right and left carbs, respectively.

The needle valves are both inscribed with 2623.

The on the side of each carb, there is a raised rectangular portion in the casting with a rectangular inset. On the left carb, this inset appears to have a piece of metal pressed in and some reddish goop (technical term) on it. Does anyone have any idea if this is how this should be or what someone might have been trying to do?

I couldn't get the carb bowls off and I didn't want to force them. I plan to buy a can of carb cleaner with basket, so I can let everything soak. I'd imagine that after soaking, the bowls will come off more easily.

Any comments or suggestions are welcomed!

Cheers!

[ggray]

If I'm not mistaken, the rectangular bosses on the sides of the carbs are where the "Key" for the throttle valves is installed. The key engages the slot on each throttle valve to ensure the valve remains "Clocked" in the correct position.

If one looks different, and it appears to be so in the photo, someone may have tried to replace or repair the key at some point in time.

Just make sure there is no resistance when sliding the throttle valve in the carb bore.

Gary

[LOUD MOUSE]

As Gary stated the area is where the slide guide is located. You will find the guide on the inside area of the slide towers so one side will have the guide and the other is just part of the casting. The one with the guide was sealed by HONDA in case air may be able to leak into the carb at that location. ................lm

If I'm not mistaken, the rectangular bosses on the sides of the carbs are where the "Key" for the throttle valves is installed. The key engages the slot on each throttle valve to ensure the valve remains "Clocked" in the correct position.

If one looks different, and it appears to be so in the photo, someone may have tried to replace or repair the key at some point in time.

Just make sure there is no resistance when sliding the throttle valve in the carb bore.

Gary

[Inty]

Right on guys! I flipped the carbs over and the key is on the other side of the right carb. Here's a picture of both carbs, still left and right as shown, but now you can see the keyway under the choke rod on the right carb.

In the last picture above, note the difference between the two needle "keepers" (not sure what these are called). The one for the left carb was pressed snuggly into the bottom of the slide while the one for the right carb fit loosely inside the slide. In pictures of carb rebuild kits, these parts seem to look like the one on the left. Not a big deal since I'll be replacing them, but it's always a little puzzling to see different parts installed into supposedly symmetrical components.

Cheers!

[LOUD MOUSE]

I suggest you replace that slide. The needle keeper is a home build for sure. You can get the keepers with carb kits. Be sure you get the kits for the oval bowl carbs. ..........................lm

Right on guys! I flipped the carbs over and the key is on the other side of the right carb. Here's a picture of both carbs, still left and right as shown, but now you can see the keyway under the choke rod on the right carb.

In the last picture above, not the difference between the two needle "keepers" (not sure what these are called). The one for the left carb was pressed snuggly into the bottom of the slide while the one for the right carb fit loosely inside the slide. In pictures of carb rebuild kits, these parts seem to look like the one on the left. Not a big deal since I'll be replacing them, but it's always a little puzzling to see different parts installed into supposedly symmetrical components.

Cheers!