Author Topic: 1972 CB500 - Rebuild Project (Read 30822 times)

SOHC4 Cafe Racer Fan · « **Reply #150 on:** October 26, 2015, 08:43:05 am »

I like how the paint came out. It'll make for a unique 500. Very REPSOL orange.

Wiggy_NZ · « **Reply #151 on:** October 28, 2015, 01:53:05 am »

Hi Puffin.... I have just finished reading you full story... You are going well for an old pom. lol. Where are you in New Zealand.... I am in Christchurch... I own a K5 750

Regards Brendan

Puffin · « **Reply #152 on:** March 10, 2016, 03:23:38 pm »

Wow so it looks like I haven't posted here since October last year...!

Christmas, New Year, starting a new job and a 6 week holiday touring around the country has meant the CB500 has taken a bit of a back seat. Now that things are settling down again it's time to get this thing finished and update this build thread. I have actually got quite a bit done and despite being crazy busy, the bike has made some significant progress and passed some big milestones.

The last time I posted it looks like I had just got the tank back so I'll back track to that point and bring you up to speed

Before I show you the bike some of you might be interested in this if you need to move your bike around... particularly if you have a van.

I bought a cheapo motorbike front wheel brace from the autoparts shop. Next I got some (free) flat bar from a fencing manufacturer and some eyes from a rigging store.

I drilled some holes in the bar to attach the eyes and a couple more to attach the wheel brace. I then bolted the whole assembly to the existing holes in the van floor where the seats used to mount - hey presto a removable bike transporter with mounting points.

calj737 · « **Reply #153 on:** March 10, 2016, 03:33:00 pm »

Question is: What do you do with the wheel chock once you've finished and no longer have to tow your bike about?

Answer: Get another project!

Puffin · « **Reply #154 on:** March 10, 2016, 03:40:46 pm »

Now for the 1st bit of big news....the exhaust.

I was introduced to a guy who had a lock up near my office who was starting up a pipe bending and welding business. He worked over at the University in the day and was building up his business in the evenings and weekends. I mentioned that I needed a new exhaust for my bike and he reckoned he could do it.

Anyway we chatted a bit more and I ended up taking the bike over to him one evening along with a load of pictures and a couple of old rusted sets of headers so he could see how the original set-up worked.

My brief was that I wanted 4-into-2 headers with an up-sweep and to retain the center and side stands if possible. I also wanted to access the oil filter without taking the exhausts off. I wanted Stainless steel and I wanted to use the reverse cone mufflers I already had.

Anyways he seemed confident so I agreed to leave the bike with him and see what he came up with. It took him a couple of months but I eventually got the call to say they were ready...

This was what he came up with...

Puffin · « **Reply #155 on:** March 10, 2016, 03:53:09 pm »

.... I'm pretty happy with the result

It's unique, hand made and he nailed every aspect of what I wanted. He cleverly fabricated a little bracket underneath which acts like a stopper for the center stand. The side stand moves freely. He got the mufflers exactly where I wanted them which means I can still adjust the chain.

His welds are immaculate and i can also access the filter easily.

If I was going to be hyper-critical I would say the bottom of the headers don't quite hug the engine as close as I anticipated but this could be adjusted by altering some of the bend angles or adding another bend in the down pipes. The result of this however is that it gives the headers quite an angular and aggressive look so I'm leaving it for now and will make a call once the bike is done.

Puffin · « **Reply #156 on:** March 10, 2016, 03:55:43 pm »

Some more pictures...

SOHC4 Cafe Racer Fan · « **Reply #157 on:** March 10, 2016, 05:41:21 pm »

Pretty damn good looking. How does it sound (running video)?

MickB · « **Reply #158 on:** March 10, 2016, 07:19:07 pm »

Fantastic, they look great!

calj737 · « **Reply #159 on:** March 10, 2016, 07:31:33 pm »

Those look fantastic!

Puffin · « **Reply #160 on:** March 14, 2016, 07:56:48 pm »

Quote from: CB750 Cafe Racer Fan on March 10, 2016, 05:41:21 pm

Pretty damn good looking. How does it sound (running video)?

Well... an excellent question and one that leads to my next milestone. I have managed to get the bike started and even drive it down the road. The first attempt she was only running on Cylinders 1 and 3 which I thought was unusual but after it had cooled down and I tried again all 4 cylinders were firing away nicely. The exhaust notes are really nice and deep without being too loud. I'll try and get some video posted soon as she does sound amazing.

I even took her down the road. She went through all the gears, took off and stopped just fine and actually rode pretty nice. Only issue was that I couldn't get it over about 3,000rpm without it bogging. I have not done any tuning or carb syncing yet so for now i'm considering this a great success...!

Puffin · « **Reply #161 on:** March 14, 2016, 08:14:03 pm »

Couple of minor jobs got completed after being further enthused by having a running bike..

- Cut out a grill for the air filter cover to keep out the leaves and stones and oiled up my uni-filter
- Addressed a leaky and sticking front caliper with a new seal and some Dow Hi-Vac grease that is often recommended in by this forum.
- Tarted up the original black metal plate

SOHC4 Cafe Racer Fan · « **Reply #162 on:** March 14, 2016, 08:27:00 pm »

This is a clean, great-looking bike.

Puffin · « **Reply #163 on:** March 14, 2016, 08:41:42 pm »

I spent a long while looking at Speedo and Tacho options.

Having swapped out the original CAM for a 650 CAM, my original tach was no use as the drive ratio on the cam gears is different. This meant I needed to go electronic or get a new analogue tach plus new drive gear.

Unfortunately I really struggled to find a mini analogue speedo in kms, that had a matching electronic tach, that looked any good.

I considered a fancy all-in-one dial but I'd never use half the functions and I just didn't think it was the right choice on this bike. My other problem was that my top clamp did not have the original mounting points as it had been modified to be used as a police bike which originally had the speedo mounted in the headlight bucket and no tach at all.

Anyway eventually I found these simple, black mini dials on Alibaba for $20 USD each including postage. Unfortunately the electronic tach didn't come with any wiring instructions but I eventually figured it all out and they seem to work just fine.

I'm not sure how accurate they are, or how long they will last, but they look really good.

I mounted them by simply installing longer bolts in the handlebar clamps which provided something for the brackets to secure to and allowed the guages to sit at the right height.

Puffin · « **Reply #164 on:** March 14, 2016, 08:54:15 pm »

Quote from: CB750 Cafe Racer Fan on March 14, 2016, 08:27:00 pm

This is a clean, great-looking bike.

Thanks, I'm so pleased how this is actually turning out. My next step is to get a seat hoop from Harisuluv and start getting a seat made up.

calj737 · « **Reply #165 on:** March 15, 2016, 06:19:29 am »

If your electronic tach is drawing a signal from the coils, then it will be highly accurate provided you have a clear, strong signal.

Puffin · « **Reply #166 on:** March 16, 2016, 01:29:26 pm »

Quote from: calj737 on March 15, 2016, 06:19:29 am

If your electronic tach is drawing a signal from the coils, then it will be highly accurate provided you have a clear, strong signal.

Thanks Cal, Yes it does. I took the tach wire and connected it directly to the coil terminal.

Puffin · « **Reply #167 on:** March 19, 2016, 05:13:54 pm »

Quote from: Wiggy_NZ on October 28, 2015, 01:53:05 am

Hi Puffin.... I have just finished reading you full story... You are going well for an old pom. lol. Where are you in New Zealand.... I am in Christchurch... I own a K5 750

Regards Brendan

Hey Brendon, Sorry I've just seen your post. I'm up in West Auckland mate.

Was riding around your neck of the woods earlier this summer as I have some family down in Christchurch. How's the 750 running?

Puffin · « **Reply #168 on:** March 19, 2016, 05:30:29 pm »

Right... video of the first test run.

As I mentioned the carbs are not synced yet so you can hear it bog down at around 3,00rpm but otherwise no smoke, no explosions, no fires, no sudden grinding of metal.... generally pretty happy.

Puffin · « **Reply #169 on:** March 19, 2016, 06:33:15 pm »

... and a video of the first start up.

SOHC4 Cafe Racer Fan · « **Reply #170 on:** March 19, 2016, 09:37:27 pm »

Yes, take 3 was much better, Kiwi! Congrats!!

Bootsey · « **Reply #171 on:** March 21, 2016, 08:15:14 pm »

Awesome work mate, the pipes look & sound great.

Puffin · « **Reply #172 on:** March 31, 2016, 03:45:54 pm »

Right my seat hoop arrived this morning courtesy of Harisuluv...

Anybody have any advice on installing? Looks fairly straight forward but always keen to hear from those who have done this before.

I know people usually do all their metal fabrication first but I have no experience in welding or fabrication or any equipment.... I also think the back end is one of the hardest things to get right and I wanted to see how the bike evolved before making a decision.

As well as getting the hoop installed I need to consider seat and indicator light mounting points so I might sketch something up this weekend. I also need to decide whether to get the seat pan made out of fiberglass or whether to go for sheet metal.

Lucky for me there is a metal workshop at my new workplace so I can hopefully swap some welding services for beer... usually seems to work. Failing that my exhaust guy can probably help me out. The guy who did my tank paint also is does custom fiberglass work so I have plenty of options in terms of getting proper help with the fabrication works.

Photos below of what I'm aiming for the back-end and seat

SOHC4 Cafe Racer Fan · « **Reply #173 on:** March 31, 2016, 05:38:15 pm »

The seats in your photos are for the most part vinyl covered fiberglass-based seats.

Go with metal!! It will hold up better to wear and tear.

MickB · « **Reply #174 on:** March 31, 2016, 10:42:37 pm »

Puffin love your air filter screen, you could use it on Alcatraz to lock thieves away who stole Dino's 750.
It'll stop rocks being sucked into the filter.

I love it, it really adds to the bike.

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Author Topic: 1972 CB500 - Rebuild Project (Read 30822 times)