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4 cheap(er) restoration tricks I found along the way

hooptytank Member
Posts: 17
Joined: Thu Aug 10, 2006 1:31 am

4 cheap(er) restoration tricks I found along the way

Post by hooptytank » Thu Sep 28, 2006 3:31 am

Hello all, I'm relativeley new to old bikes, but not to the restoration of things. I'm always looking for a cheaper alternative, a way to refurbish something instead of replacing it, or making a part myself instead of buying something much more expensive. Fact is I want my toys to be functional, not NOS trailer queens. There is nothing wrong with a perfect restoration, they are just beautiful but I would be afraid to ride/drive it. Follow along as I try to describe 4 good(in my opinion) cheap tricks I did for my CB77:

1. Replace the selenium rectifier! You are living in the 21st Century, and so should your electrical system. Get a full wave bridge rectifier from a place like Radio Shack p/n 276-1185 for about $3.30. This is the same diode sold on Ebay for $20!!! One of the nice things about this diode is the hole in the center of its housing, that can be tapped with a M6x1.0 mm tap to accept a 6mm screw. I mounted mine using a 6x16mm screw with a lockwasher and a flat washer on the right side tab where the old rectifier mounted to. You'll need to file or drill the slot abot 1mm bigger for the bolt to fit. I also used this bolt to connect the ground lead of the diode via an eye bolt connector. Make sure to sand the tab down to bare metal where the ground lead makes contact, and use a bit of dielectric grease to prevent rust. For more info on hooking it up see Total install time and savings about 45 min and $20

more about the diode: The generic name for this diode is KBPC2501 (Google it) where KBPC is the housing material and shape, metal in this case, 25 is the rated amperage and 01 means it can handle up to 100 Volts. There are many versions including GBPC-xxxx which is made mostly of plastic, but will do the same job. Different amperage ratings 15, 25, 35 and range from 50-800 Volts are described in the numeric value. for example KBPC3502 has a 35 A, 200 V rating etc. but all you need is KBPC2501.

2. Battery hold down. Mine was gone, finding one has been impossible, and I'm using zip ties less and less for permanent repairs as I get older ^_^. Get a battery strap for a CT70 or equivalent, honda p/n 50382-098-000, about $6 at any honda dealer. one of the metal hooks of the hold down grabs the hook on the frame, the other gets bolted down to the original mounting hole with a washer. Make sure there is no interference to the seat alignment tab when putting the seat back on. Total install time and savings about 5 min and $???

3. Air fiters(assuming you still have your cages). desintegrating 40 year old paper with missing chunks doesn't cut it anymore. Cut it all off right near the glue/epoxy. I heated the back side of the epoxy(the outside metal part) w/ a propane torch evenly around until smoke was coming out. That stuff smokes more than Cheech an Chong, so do it outside! At this point the bond to the metal is broken and you can separate the pieces. Scrape all the old epoxy off, and clean w/ breake cleaner or equivalent. To preciseley fit the screen back to the ends I mounted the ends back in their location on the bike, and used "The Right Stuff" which is similar to Ultra Black RTV but better, to glue the screen to the end caps. Make sure you check the distance from the end cap edge to the screen so its centered right. The metal channel is supposed to bottom out on the inside edge. Once done you may want to use masking tape to draw the ends together. Let it set up overnight. Once its all set up give it a light coat of your favorite colored paint.

In the mean time find UNI Filter Bulk foam p/n BF-1, or any kind of air filter foam, or just foam. The UNI stuff is a large piece of 1/2" thick foam, enough to do both filters. Remember, measure 2x cut once,foam can be squeezed into place, so an extra 1/8-1/4" won't hurt! Cut out the required amount(not sure of dimentions anymore) and do a dry test fit. Use 3M super adhesive 90 spray to coat the end caps and the edges of the foam and a little spray on the inside of the foam and the wire screen. Wait about 1-2 minutes for the glue to tack up, then start attching the foam to the angled side of the metal channel and work your way around. Once its all in place use masking tape to hold the foam down until the glue cures. I rolled up the foam and used tape to keep it rolled tight for about an hour before doing this to give it a nice curved shape that will fit a little better.

I'm running the foam dry, because Im afraid of having to clean the filters(they will be a bit more fragile than before).Baby oil might be easy to clean, but it may dry up. I also tried soldering the pieces together but they are coated with zinc or something that prevented good adhesion even after a good cleaning and sanding to bare metal. Brazing might work... Total install time and savings: about 2-3 hours including finding materials and up to $60 if you have the adhesive,paint and silicone already

4. Air cleaner connecting tubes. I only had one of mine and it looked like swiss cheese. Buy 2 p/n 8803 radiator hoses from Napa. you can find the same hoses at probably any auto parts store but you'll have to do your own cross referencing. Also get 4 #24 hose clamps, as the stock springs don't have enough tension. Use your old hoses as templates and cut the proper length with a sharp knife. Again measure 2x and cut once, this stuff is hard to glue back together. Finish trimming can be done with a bench grinder. The 2 cuts will be at different angles and once installed the centerline of the curve will point to about the 1 and 11 o'clock positions for the L and R sides, respectivly (towards each other). If cut and fit right these will fit and look as good as a brand new pair. Install the hose clamps on the carbs with the srews on the inside and all that will be seen is a shiny chrome strip! The clamps on the filter end is behind the cover. Cut off excess hose clamp end for a super clean look. Total install time and savings about 30 min and $55

There you have it... you are now about $135 closer to buying an electronic ignition from this site!! Can I get a discount? hehe
Happy tinkering! and ask questions if you have any, but none about my sanity, please,

kustommusic Member
Posts: 585
Joined: Sat Sep 11, 2004 6:44 pm
Location: Goshen Indiana

Post by kustommusic » Thu Sep 28, 2006 3:34 pm

Good Stuff!

jesmed Member
Posts: 79
Joined: Tue Jun 14, 2005 4:53 pm
Location: Cambridge, MA

Post by jesmed » Fri Oct 20, 2006 12:00 pm

Hoopty, thanks for taking the time to share these good tips. I did buy an eBay rectifier last year, but if I fry it, I'll head to Radio Shack next. And my air filters and tubes are going to need some help soon. I've staved off tubular disintegration by wrapping them with aluminum duct tape, but some new inexpensive rubber would be nice! I'm printing your tips out and saving for when I need them. Much appreciated. Jesse

allthumbs Member
Posts: 131
Joined: Tue May 06, 2008 7:33 am
Location: Beacon, NY

Post by allthumbs » Thu May 15, 2008 4:27 pm

I just bought the ebay rectifier too, you said you spent 20 US by the end of it anyway, I guess you learned more doing it.

did you use a heat sink? the ebay guy claims you don't need one


jesmed Member
Posts: 79
Joined: Tue Jun 14, 2005 4:53 pm
Location: Cambridge, MA

Post by jesmed » Thu May 15, 2008 5:25 pm

I did not install a heat sink with my eBay rectifier, but I did take the advice of the original poster above and use dielectric grease between the rectifier case and the frame to ensure good ground, and also on the rectifier connections. I installed the rectifier about 3 yrs ago and never had a problem.

hooptytank Member
Posts: 17
Joined: Thu Aug 10, 2006 1:31 am

Post by hooptytank » Thu May 15, 2008 8:39 pm

I didn't use a heatsink, but the mounting location on the frame and the grease aid in heat transfer. 900 miles later and no problems.

deaddog Member
Posts: 165
Joined: Fri Feb 23, 2007 9:33 pm
Location: South Florida

Post by deaddog » Fri May 16, 2008 1:19 pm

With heat sink under $10.00 for repair.

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