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Re-Awakening the CB750c - Part 2

Side covers back on after 5 years of being parked
In Part 1 of Re-Awakening the CB750c, I ran into a few bumps in the road while I went through the bike after leaving it in my garage for about 5 years.

Time sure flies when life gets busy.

After getting the new Dyna coils installed and the new spark plug wires crimped I was excited to see my bike start with just the intention of my finger hovering over the start button.  Unfortunately, my hopes did not pan out as I imagined they would.

No Start.

I tried to pump the gas a few times without actually flooding my new D8EA spark plugs that I installed during troubleshooting the old ignition parts but managed only a few backfires.  I eventually figured out that I had the signal wires crossed for the ignition coils. (blue needs to go to left coil for cylinders 1 and 4, yellow needs to go to the right coil for cylinders 2 and 3).

Once I had the wires installed properly, the bike stumbled to life with the first push of the starter button but still needed choke for a few minutes.  I decided to wash all the dust off and take it out for some fresh gas.  I wanted to get a little seat of the pants riding in as-is so I can make a comparison between this exhaust system and the original 4-4 exhaust so here are my impressions as she sits today.

It starts EASY now, so far the first press of the starter will fire the bike (without priming) which is a huge change from before.  Even after sitting for 2 days, without any additional fuel in the bowls, the bike will fire and stumble with whatever fumes might be present. This is a big deal!

The BST36 carbs were also easy to start but this feels stronger and freer revving once it's warmed up and the idle speed is a touch higher now. I'll have to remember to turn it down next time since it's idling around 1500 and I want it closer to 1100.

The engine revs easily past 7k rpm where it starts pulling very hard and I don't think it's ever run this well in 10 years of wrenching on this bike. The new accelerator pump is working much better compared to the incorrect part which I cut-to-fit last time.

Are the Dyna coils worth the money? If you have the money to spend, they are worth every penny.  If you don't have the cash? it's time to start saving. The best deal I found for the Dyna coils were on eBay. I found the coils, wires, terminals and spark plug tops for $128.20 shipped from seller ATV Galaxy.

Installation is tricky. The coils must be loosely mounted and prewired before they should be attached to the bike.  The main wire harness should be pushed down below the wiring tab to make space for the spark plug wire on the left side coil.  The wires should face front and this is most likely the ONLY way to successfully install the coils.

I'm expecting to discover new things that need repair but I hope there are no issues with my charging system since I went through that stuff a few years ago.  My blinkers are not working properly. They don't blink with the engine idling but blink fine with the engine off or revving above 2k rpm.  After switching to the DR8EIX plugs (resistor) the blinker weirdness is completely gone.

NOTE: 
Running non-resistor wires with non-resistor plugs will cause trouble for electronic blinker relays (and in fact anything electronic)

I upgraded to a smaller bore master cylinder (upgrade to 1/2" from the OEM 14mm size) in a previous post about the brakes (contrary to my expectation of needing a larger piston for better braking) and though the lever feel was much improved, I had a little too much lever travel such that if I 2 finger braked, the other 2 fingers would get caught under the lever as it squeezed almost down to the throttle. I didn't realize (or forgot) that I still might have some air in the system after all these years and decided to try something I read online because it didn't cost anything.

I clamped the brake lever down overnight and turned the bars to the left fully to maximize the master cylinder height. When I un-clamped the brake I discovered that my lever travel is much shorter with plenty of room for 2 finger braking.

I've been waffling on making more visual changes to this bike but it looks pretty neat in close to stock condition. That rear tail light has bothered me from day 1 but I have not yet thought of a solution forward.

I do still have a few things to purchase, and over the next few months plan on these things:
-new tires
-LED Headlight
-LED turn signals
-replace missing Shifter cushion
-find something to stop my hand from going numb after 10 minutes
-install a voltmeter


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