Topic: CB750K4. Light frame mod and performance upgrades.

[D-Ral]

Ill try jumping the horn to the battery when I get home from work.

[D-Ral]

Ok, I figured it out. There is a small plate that is screwed inside the left hand switch assembly. I thought it was just to retain wires, but it also pressed against the handlebar, making the ground to frame for the switch. I think, anyway. Either way, it works now.

So I ordered some points and condensers. I ordered them for vintagecb750.com. They didn't give the brand name. After I ordered them, I started reading up on points. I read many times not to bother with anything made by Diachi. Of course, when my points arrive, they are Diachi. Ha ha. Go figure.

[iron_worker]

Most of the parts vintageCB750 sells are knock offs and reproduction parts ... I've been disappointed with their parts more than once unfortunately.

IW

[D-Ral]

Yeah, I think I've learned. I'm always just trying to save a buck and it gets me into trouble.

[D-Ral]

Yesterday I adjusted the valves, but couldn't start the bike afterwards due to the battery, (I hope.) It read a little less then 11 volts while sitting, and had a drop to somewhere between 5 and 6 with the starter down. I read another post that indicates my battery is toast if it shows a significant drop when hitting the starter, but my battery is only a couple months old. It's idled for as long as ten minutes maybe twice, but the bike hasn't moved. I took it to the battery shop, and they said that they'd charge it up for me, but I'm hoping they'll load test it to determine if it's a dud.

Since they still have the battery, I spent the morning wiring my turn signals. I picked up some cheap plastic blinkers on eBay a few months ago for five bucks. Attached the rears to the spots on the stock grab bar and drilled out my headlight ears for the fronts.





Because I have no battery, I can't test my turn signals, but I'm pretty confident I wired em up properly.  However, I have an extra light blue and orange wire  coming through the harness to the headlight bucket.



I checked for continuity between these and the light blue and orange at the rear of the bike and they are not connected. Not really sure what they are for.

Front signals are single filaments, so I assumed that the orange and light blue with white strips are for the running lights. I'm left with those and the brown striped wire for the signal buzzer not being used.



I ran out of places to plug in ground wires, so I made my own.



The only other strange thing going on in the headlight bucket is the wiring of the clutch switch. The wiring diagram on Old Man Honda's website shows a clutch switch receiving a ground wire and a green wire with a red stripe. The switch tells the safety module wether the clutch is pulled or not. I don't have a clutch switch. The PO had the ground and green with red stripe joined in the headlight bucket. Is this proper?



Here is my beautifully attached key switch.



Got insurance on the bike the other day. If I don't get my battery back tomorrow, I'll go to the DMV and get my plates.

[D-Ral]

Okay, major progress. I got my battery back and the bike fired up. Turn signals didnt work right away, but I switched the wires at the flasher relay and then they kicked in. I adjust my points, sort of. The 2.3 bolt wouldn't move and I ended up stripping it. However, it seems to be adjusted properly anyway. I got a cheap timing light, and set the timing on the 1.4, but ended up melting the inductive lead on the headers, like an idiot. Ha ha. Oh well, it def ran better after half the timing is set. A friend has a light, so hopefully he will bring that over tomorrow.

I adjusted the cam chain before the valves, but I still hear a lot of rattling at idle. Something is shaking around in there. When I loosen the adjuster bolt on the tensioner, should I hear a click or something? I'm not really sure how I'd know if there I something wrong with my tensioner.

Other than the clanging around, here is another thing I notice. In order to get the bike started, I turn the idle screw a fair bit. Once it starts warming up, I need to turn it back without bumping the choke, because that causes the idle to race. Choke is closed. Slowly turn the throttle back as the idle goes up, and then open the choke and it will idle steadily around 1000. Sometimes I hear a little gap in the engine growl, not sure how to describe that properly. Anyway, I know the timing needs to be completed and the carbs need to be synced as well, so I'll wait until I do that.

Also, I'm getting sparking from my points. Is this normal?

[D-Ral]

Oh, and I went for a spin around the block! Wasn't expected it to be as responsive as it is.

[D-Ral]

Alright, time for an update. Bike is rideable, safety inspected, and plated. Woohoo!





Before I took it to get safetied, I had to finish adjusting the timing and sync the carbs. Broke two points bolts in the process, but was able to pull em out with some easy-out type devices. And I had ordered some extras with the crappy points I ordered and never installed.

Carb sync was straight forward, but getting the brass adapters on the carbs was a bit of a hassle. Not a lot of room in there.

So, here is what I've noticed after a couple rides:

Firstly, I still haven't quite figured out the best way to start the bike when it's cold. The choke doesn't really seem to help much. In the end, I feel that turning the idle screw is the only option, but that is a PITA because my petcock is on the left. To get at it I need to lift the tank.

Secondly, it doesn't really want to idle smoothly when lower than 1300 rpm. Is this normal?

And thirdly, I will turn the bike on, warm it up, and let it idle at 1300. After about 20 minutes of riding, the idle is about 2000. Is this normal? It's been extremely hot and muggy lately. I'm not sure if that has anything to do with it. I'm wondering how the turning the air screws would change things. Currently, all are turned 1 turn out.

Anyway, the bike runs and life is good. Next is to come up with a plan for some cosmetic changes.

[evanphi]

Just replying so I can sub to this thread! Maritime SOHC4s!

[D-Ral]

Ok, I'm back.

Firstly, I figured out my idling issues. Instead of holding my throttle open, I would adjust my idle screw every single time I started the bike. When it warmed up I would turn the idle back down. After messing with the air screws and no longer messing with my idle, I noticed how quickly the bike would warm up to the point where I didn't have to coddle it with some throttle while idling.

Originally I got the bike to learn about engines and mechanical #$%*, but it turned out to be pretty damn fun to ride, too. Here are some photos from the summer:



New mirror.





Found some cruddy old side cover emblems and spray bombed my covers. I like the used look of my tank and covers.







Found some old tank emblems for a steal!

And that is how she looked before I decided to put her away for the winter.

[D-Ral]

After careful consideration, I've thought out a plan for this bike. Because this is my only ride, it's important that it's running by the time the snow melts.

Progressive style shocks and fork springs.
New tail and signal lights with custom fabricated mounts.
Rearsets.
Frame hoop.
Seat pan and brat style seat.
Rebuild swing arm with bronze bushings.
Powdercoat everything and replace hardware with SS.
Wrap exhaust and install new muffler.

I don't have the cash to powder and rebuild my wheels this winter, so I will leave them alone for now. Also, I'm not quite sure what I'd like to do to the engine while it's out. It deserves paint, eventually, but I want to wait until something actually goes wrong before I crack the cases.

So, this doesn't seem like a lot, really. However, I have another project on the go with a couple of friends and don't have a lot of time. Plus, I'm dependant on one of my friends to do all of the welding and help me with the fabrication. We will see how it goes.

SO… I didn't want to be in my cold shed all winter. So we put it in the basement!







It didn't turn out too bad, actually. Nobody got run over.

[D-Ral]

First thing on the list is to fit the hoop and new shocks. I bought the hoop from another forum user, Harisuluv. At least I think that's his name…  I picked up some cheap new shocks with progressive style springs from a local shop. Instead of 13", they are 14.4". I'll get a steering damper if I feel it becomes too twitchy.

Mocked up the shocks.





Then I fit the hoop, first by chopping the rear part of the frame and then cutting horizontally so i could just lay the hoop in the frame gusset:





Once I was able to peel the hot frame tube out of the gusset, the slugs that came with the hoop slid right into the frame. I just beat the gussets up against the hoop with a mallet and used a clamp to complete the mock up.

[D-Ral]

Another thing I've decided to add to my list is a HM ignition. The price is right, and if his ignition is as proficient as his book, I'll be a happy rider.

The other day I decided to mock up an oil tank:



Fits nicely, but I've decided against it. Firstly, due to cost. I'd have to buy a compact battery and move all of my electronics. Secondly, I'm worried it would just eat too much time. Maybe one day. I have another CB550 project in my future, so I think I'll save the relocation for that.

[D-Ral]

When I originally cleaned my carbs I found a broken choke flap on carb #3. The spring had broken and left the flap hanging with only a fraction of the tension it should have.

Look what I found in my airbox:



I suppose I'm lucky it didn't get sucked into the engine! I picked up a replacement choke slide from Harisuluv last year, so I took this opportunity to install it.

[D-Ral]

I think I attempted another post last week, but ended up getting frustrated after losing it before I could post it.

Anyway, I tore down most things I don't need to mock up my seat and rearsets.





I also managed to get the rear hoop welded on. Still have to clean up the welds.

[D-Ral]

Next, I chopped my passenger brackets off.



My plan was simply to shorten the brackets, reweld to the frame shorten the supplied linkage, and mount. However, my 'bolt on' rear sets are going to require some manipulation. Firstly, the supplied bolt is not going to work. It's not wide enough, nor is it long enough. Secondly, the toe peg on the brake side is going to interfere with the brake spindle unless entire rearset is pushed away from the frame a bit. I'm going to wait for my muffler to show up before I continue with the foot controls.

[D-Ral]

Cleaned up my airbox and installed new rubber boots this afternoon. Got my boots from vintagecb750.com. They are cheap, soft, and easy to install. They look identical to OEM. Used Mother's Back to Black to refinish the box. Worked fairly well. I'll pick up some stainless hardware to finish her off.

My old horns are flat on one side from being installed upside down. The flat side pressed against the filter.





Also, I ordered a couple things from Bullit Customs in Toronto. Cycle X shorty, Joker tach plug, and some soft fork gaitors that don't require OEM headlight ears. I'm sure they'll show up soon after they get their power back from losing it in the ice storm.

[Ford40]

Looking good, what are you planning to do with your old seat if you don't mind me asking?

[D-Ral]

It's all yours. It's not in the best of shape, however. It needs to be recovered and there is a little bit of rust starting on the underside of the pan. I can send you photos.

[evanphi]

Were you welding next to your home's oil tank!?!

[D-Ral]

Ha ha. Nah, not beside it. I push the bike around on the lift whenever I want to avoid an insurance claim/human catastrophe.

[D-Ral]

Mocked up and made my seat pan. I went out yesterday and grabbed some black marine vinyl, heavy duty thread and foam for the seat. Messed with my neighbour's sewing machine for a bit tonight, but spent most of that time trying to get it to make a steady stitch. I think I'll hit up Kijiji for a used one tomorrow.

I've found some basic YouTube videos for sewing basics, and I'm familiar with threading the machine and stitches, but if anyone knows of any tutorials that are more specific to this purpose, let me know.

[evanphi]

Sidebar: I love sewing. I have a 1953 Sewmor machine. Still has a little note from the first person that bought it, etc. This isn't mine, but the same model:



Also I think this is just what you need. It shows how you need a thin foam layer under the vinyl if you want to have some "pleats" or a stitched design. Then you need a "skirt" around the edge, and this is what would be tacked under the seat pan.
pleated motorcycle seat build

[D-Ral]

Yeah, I have seen that video. Bugged me that he sped it up and didn't really explain much. I watched a couple others and then messed with my neighbours old machine for a bit. Pretty sure I've got a grasp of it.

I wanted an industrial machine, but there isn't much on Kijiji (cl) in my area that I could afford. Instead, I picked this up for 50 bucks. Old lady driven:





Came with a whole pile of presser feet and whatnot. Materials are pretty cheap, I found out.



Marine vinyl, foam, plus outdoor thread and a needle well suited to the vinyl.

After threading the machine and messing around a bit, I realize that the foam is too thick, and that to make my pleated section I'll need to pick up some thin backing material.



Cruddy stitch. Material won't flow through the machine. Switched to a plastic foot. Here is a stitch without the foam:



Looks good, but I lessened the number of stitches per inch afterwards. Here is the thickness of the foam and what happened wen I tried using another piece of vinyl as a backing:







You can see in the last image that the stitch gaps are off here and there, but it was definitely the most successful line. I'll pick up some different stuff tomorrow and give it another go.

[calj737]

You might try kerf cuts in the foam to aide in laying stitches to make pleats. Most pleated  seats I've seen are made using a much thicker foam, or the top fabric is actually folded, stitched, then stretched to next pleat line.