Monday, September 28, 2009

Taking a break from the CB125 to rebuild CB360 carbs

I decided to take a little break from the cb125 this weekend and focus on my 1976 CB360t. This bike is running, but the throttle has always been a little off. Doesn't run well at low throttle and occasionally loses power when starting (like the choke is on when it isn't).

I feel sort of weird about taking apart a running motorcycle when I have so many projects going on, but I just have to feel that sense of completion with one of these bikes - and this carb overhaul was badly needed.

I bought a set of carburetor rebuild kits off of Ebay. They showed up on Friday and I just couldn't wait to get started. Off with the tank and air filters...

Not only are these carbs a little sticky, but they're filthy on the outside and just begging for a cleaning.

Ah, how satisfying the bead blaster is.

This grime was scraped out of the bottom of the carb under the floats.

The Carburetors on the CB360 are much more complicated than the one on my cb125

Lots of carb cleaner. Had to make a pep boys run to grab another two bottles.

looking better. At this point I changed out the jetting and air intakes that came with the rebuild kits. All the new jets are the same size that came with the bike originally since I'm not planning on modifying the air filters at this point. I just want to keep this simple (and running).

Once everything was rebuilt I had a little trouble putting the two carbs back together. After some fiddling I finally got everything to line up properly.

Carbs look great but I wasn't sure if they'd work right off the bat. I'd never done an overhaul like this and I wasn't sure how sensitive they'd be.

Carbs back in the bike and after a couple of kicks to get some gas through the system, the bike fired up!

I took the bike for a quick test ride and so far so good. It runs better at low throttle than it did before and it idles better. I may have to me a few adjustments here and there, but for now I think I can check this job off my list.

Now back to work on the CB125...

Wednesday, September 23, 2009

Fishing for piston-pin clip

About the time I pulled the top end off the engine and destroyed the piston with the blunt end of a drill bit, I decided I would pull the clips off either side of the piston pin so I could toss the damaged piece. While I was very careful when removing the clips, I managed to drop one down into the engine case. Oops. Since that little mishap I have tried and failed to retrieve that clip. I've tried a Shopvac, flipping the engine upside down and shaking it (not sure if that's a good idea or not) and fishing around with a long piece of safety wire all to no avail.

The other day I was rooting around the garage and I came across a funny looking device, still in plastic, labeled tool retriever. Essentially it's a long spring with a magnet attached to the end. Hmm, this might be just what I needed.

I stuck the magnetic side down into the opening for the cam chain. It didn't go very far due to the gear being in the way. As I pulled the "tool retriever" out, I thought 'wouldn't it be awesome if the clip was stuck to the magnet first try?'

Well low and behold it was! 2 months of that loose clip on the back of my mind are now laid to rest.

This took place Sunday morning. Finished up in the garage and suited Katherine (My one Chihuahua) in her Eagles gear. Usually that brings good luck to the Birds, but this time it didn't help. 48-22 New Orleans...

Saturday, September 19, 2009

Bead Blasting fun and staging the final look

I came across a 1965 Ducati SCR tank that looked about the right size and shape for my CB125 cafe bike. The stock tank that came with the motorcycle was rusted out and rather ugly to begin with. The Ducati tank gives this that streamlined, European look I want. The tank is pretty clean inside, but needs some serious outside cosmetics.

Still looking for a cap and petcock for this. Eventually I will strip the paint, lead load the dents and re-finish the tank in a color yet to be determined.

For now, I essentially have all the components for the finished bike (minus the seat I plan to fabricate by hand) so I couldn't resist propping everything together to see how it looks. Keep in mind that nothing is bolted or finalized. The tank will end up at a slightly different angle, the drop bars will be narrowed, the front forks will be lowered etc... For the sake of visualization, I quickly made a seat out of cardboard and duct tape to show how the lines of the finished seat might work with the frame and tank.

With everything pieced together I got a rush of excitement. This pipe-dream project is becoming a reality. I really like the way the mock up looks, but I can see where I want to make some modifications.

You can see some of the dents in the tank that need to be addressed:

Another darker shot of the "finished" bike:

The other day I received my Abrasive Blaster in the mail. I forgot to take a picture of it set up in my shop, but here's the amazon photo (yup bought it on amazon for a really cheap price):
The abrasive blaster is really just a bucket with a siphon hose that connects to an air-gun. The box keeps the glass beads (really REALLY fine sand) from going all over the place.

I started with the Cylinder section of the engine. I masked off the actual cylinder openings as I didn't want any abrasion to the inside bore.

Also the Cylinder head got blasted. Once again I masked off any openings to the engine.

Man this works well. It took all the grit and grime right off and left it looking brand new!

The Top end is cleaned, though I think I need to take the valves apart and clean them before I rebuild the engine.

Sadly, I didn't take a close up of this when it was filthy. Let's just say it looks much better now.

I popped out the o-rings on the stator cover before blasting. The o-rings seemed fine, so I cleaned them and reinserted them into the groove where they belong.

It's all about getting the dirt out of any raised or indented lettering. It really makes the piece look factory fresh!

Lots more to do this week. More blasting, wheel truing, body leading etc.... Check back soon!

Friday, September 11, 2009

Clean wheels and respoking

The wheels on the bike were in pretty rough shape - especially the front. I tried using steel wool on the spokes but it was a lost cause. I purchased from Ebay a used, but decent set of spokes that came off another cb125. These I was able to clean up quite nicely. I removed all the rusty spokes and cleaned the rim and hub. Respoking is challenging - you have to get the order correct or it will screw the whole wheel up big time. I made the mistake of going into this blindly. Instead of dropping each row all in at once, I tried doing one at a time. Problem is things get a bit tangled as the second third and forth layers go in. If only I had seen this guys video blog before I started. At least when it comes time for truing the wheel, I'll know what to expect.

I finally got the front wheel finished and it's ready for truing. The back wheel was much better. I did, however, spend several hours cleaning every spoke with steel wool, It probably would have been easier to simply take the whole thing apart for cleaning as it has to be trued as well anyway. The wheels look great, I feel great, time for a well deserved nap with Penelope.