CB360 Project

[Gweenz]

Hi everyone

Fairly new to the site and motorcycles in general. I had done a little riding here and there throughout my life, my brother was always into bikes. A couple years ago the bug bit me and wouldn't let go, and I went out and purchased my first motorcycle, my 88 Hawk GT. Last fall, I bought a 75 CB360 in nonrunning condition but 95% complete for $150, and with some new gas and clean carbs I managed to get it back on the road. It was fun to ride but needed a lot of work, so I decided on a teardown.

This is it before the teardown, bad pic I know but you've seen 360's before. Rear tire went flat, not sure why but I just had that tube replaced 300 miles ago.

I'm currently working on the frame, cutting tabs and smoothing. I don't plan on rebuilding the engine as it doesn't burn oil or smoke and a compression test came out better than I expected. It will be getting new gaskets. The carbs are good, except for the diaphragms which have a couple small tears. Instead of spending money on those I might just get some Mikuni's. The stock exhaust is in great shape but those mufflers are HUGE so I'm thinking about a 2-1 setup. I'll be taking more pictures once I get past the tedious frame work. :-\

 

[Tim]

When you did the rear tire did you replace the rim strip and tube?

Looking forward to seeing this progress! I love Mikuni's personally and wouln'd pay $0.10 to rebuild CV carbs vs. replacing with Mikuni VM's.

 

[teazer]

I love specials and customized bikes, but I wouldn't change much on that one. I'd clean the carbs and points and keep the stock air box, carbs and pipes. Replacement exhausts make more noise but less power unless we're talking full race motor.

I'd clean it up and keep riding it. The reason I say that is A/ because I have so many projects and I know how hard it is to maintain focus and actually finish a bike and B/ I see so many poorly though out bikes that run and look worse than stock.

But that's just me.

 

[Gweenz]

My brother fixed it the first time, I assume he used a new tube but I didn't ask, he might have just repaired the old one.

I love specials and customized bikes, but I wouldn't change much on that one. I'd clean the carbs and points and keep the stock air box, carbs and pipes. Replacement exhausts make more noise but less power unless we're talking full race motor.

I'd clean it up and keep riding it. The reason I say that is A/ because I have so many projects and I know how hard it is to maintain focus and actually finish a bike and B/ I see so many poorly though out bikes that run and look worse than stock.

But that's just me.

I hear you. I don't plan on making extensive mods to the bike, I like to keep things fairly close to a stock look. Clean and simple is what I like. As for the carbs, replacing the diaphrams is going to be expensive, and that's money that could be put towards a better set of carbs. The only thing I don't like about the stock mufflers is how big they are. This bike was in need of at least a partial teardown, the rear shocks were shot, the fronts need new seals, and the swingarm bushings need replacement, with bronze ones. The bike ran and drove before the teardown, but the suspension (lack therof) made it a pretty scary ride.

 

[Gweenz]

I've been playing with a can of Rustoleum "Hammered" paint and I really like the results. It seems to be very durable so I will be using it for the frame and swingarm. My only problem with it is the black isn't really black, it's dark grey. In pictures it looks silver. Finish is similar to powdercoat:

 

[Gweenz]

My kingdom for an impact wrench.

Got the frame prep finished and engine side covers off today. Those phillips screws should be put in the lowest, darkest level of hardware hell. A couple came off with a phillips head and a bit of luck. EVERY other one was removed with a combination of dremel (cut a flat head groove), ez out, or if all else failed, a hammer and large flathead or chisel. Thankfully that's over, can someone point me towards a list of screw sizes for the side covers, points cover, and starter motor? Everything is getting replaced with stainless allen screws. I know you can buy sets on ebay but I'm cheap.

Cleaned the sludge out of the filter, and emptied out the screen which had a few small metal flakes on it but nothing to worry about. So far the engine looks good. New gaskets and a lot of cleaning and paint and it's done.

 

[jmemmert]

should be 6mm screws

 

[KrashManhatten]

keep the stock air box, carbs and pipes. Replacement exhausts make more noise but less power unless we're talking full race motor.

I would have to disagree with that comment, i too have a 74 360, and some of the best moves were dumping the rear portions of the exhaust, making custom baffles, pod filters, and now that i have had it with stock carbs and the diaphgram BS, the new Makuni might be my ticket.

less power, not really, ask the guys at work with hernias becuase they were laughing too hard cause the hondaratti was doing some smokie burnouts, at lunch time.

 

[teazer]

Each to their own. I've seen way too many modified bikes that went slower than stock. If you happen to be an exhaust and intake expert, that's fine, but how many threads does the world need with people complaining that they can't get the bike to run right because they messed with the intakes and exhausts.

A moped can do burn outs, that doesn't prove a whole lot, however amusing it may be for your work mates.

 

[Gweenz]

I'm certainly no expert when it comes to intake/exhaust. Paint is drying, so I've been drinking a lot of coffee and reading through old threads today about exhaust, aftermarket carbs, and jetting. It seems that getting it to run right when you swap filters/carbs/exhaust can be a real pain, due to all the different variables. Running correctly and reliably is the main focus for the engine on this bike, not performance. Ideally I'd like to stay with stock parts to avoid these hassles, I would prefer not to rejet a dozen times to get things running correctly. Of course the problem I keep coming back to is the torn diaphragms. If I can replace them cheaply I will keep the stock carbs as I know they work and am familiar with them. I've attempted to fix the rubber on them with Hondabond, but when I took them apart again recently it was apparent that air was getting past the "fix". What I won't do is pay $90 each for NOS carb slides.

Ideally I would like to run stock carbs and exhaust, with pod filters (mostly for looks, don't hate me). This would probably require a rejetting, but nothing too drastic.

 

[KrashManhatten]

coming back to is the torn diaphragms. If I can replace them cheaply I will keep the stock carbs as I know they work and am familiar with them. I've attempted to fix the rubber on them with Hondabond, but when I took them apart again recently it was apparent that air was getting past the "fix". What I won't do is pay $90 each for NOS carb slides.

Ideally I would like to run stock carbs and exhaust, with pod filters (mostly for looks, don't hate me). This would probably require a rejetting, but nothing too drastic.

let me know what you decide to go with, i also have a torn left carb diaphram, Real xpensive for the stocker replacement, i have been trying to think of a differnt material to use, but nothing is really coming at me.

i too have tryed the glue stuff, and it worked for about 2 months, and then pooped out, couldnt get past 4k. good luck, and regardless of what we all say and think, you are the one who has to ride it, and deal with the public intrest, and there will be some.

have fun!

 

[Gweenz]

Lots of progress made, despite my lack of updates ;D

Frame:

Swingarm:

After much soul searching I decided not to hack up the frame. I just couldn't take another titled frame away from it's stock condition. I replaced the stock swingarm bushings with bronze ones. Who doesn't like a tight rear end? I'm currently working on the motor, it's clean and painted. Side covers are going to be bare metal.

 

[dirtbag]

How did you get the original bushings out of the swing arm?

 

[Gweenz]

How did you get the original bushings out of the swing arm?

Hacksaw through the bolt hole. I cut a small (1 cm) section out of each bushing to release the pressure on them. Then they slid right out when I pinched the gap together. You just have to be very careful with the saw not to cut into the swingarm. To get the new ones in I put the bushings in the freezer for an hour and the swingarm in the oven @200 degrees for about 20 minutes. Then I grabbed both and as quickly as I could got the bushing in the hole and worked it in with a piece of wood and rubber mallet. Blacksmithing, kitchen style! Don't try this unless you are unmarried.

 

[mantanab5]

That is an awesome bushing installation method... I just ordered some bronze bushing and will hopefully be getting by frame and swingarm painted this week so that is actually really helpful. Looking forward to seeing how this build comes together.

 

[Gweenz]

About brakes....

As most of you know, the disc brakes on these bikes were barely an upgrade over the drums. I was wondering, what improvements could I make to the system? I plan on rebuilding both the caliper and master, but that won't make it better than stock. Has anyone had any luck retrofitting a different braking system (caliper, master, lines) on a 360?

My other option is to replace the disc with a drum, I have a drum front wheel sitting around somewhere.

 

[dirtbag]

I put steel braided lines on mine.

Brakes are overrated anyway. Just put steel braided, rebuild and be happy with it. It isn't a race bike.

 

[Gweenz]

Got the motor back in the frame today:

I left the valve cover unpainted but I'm not sure I like it. Side covers still need finishing.

 

[IndieSol]

Nice work so far. Did you also change out your rear suspension bushings on the swingarm? I figured I'd replace them while I was at it, but I can't figure out how to get them out. I've wacked a bit, but I don't want to damage the swingarm.

 

[Gweenz]

Wow, I totally forgot I started this thread. Hard to keep up on these when you live in Wisconsin without a heated garage. The weather has been beautiful this spring and I've had plenty of opportunities to work on the project.

Time to get everyone caught up through the magic of pictures.

Getting somewhere:

Ok, it runs and it's legal (well, almost) but it sure is ugly.

I like to learn new skills while inhaling noxious fumes. Time to make a cafe seat out of fiberglass!

Not too bad for a first timer. A few gelcoats and some sanding and it's starting to look pretty good.

...and that brings us up to today. I am currently making a fiberglass battery box for the 12v 5ah alarm battery I bought. What I've done so far:

New fork seals
Rebuilt master cylinder
New wheel bearings
Bronze swingarm bushings
New various gaskets
New clutch cable
Painted frame and motor
Polished side covers
Lots of other stuff I'm forgetting

Needs:

Rear shocks
Stainless steel brake lines
Seat finished
Battery box
Wire management