Light Cross Country Tourer

Piner

New Member
Hey Folks! I am new to the site but not to CB750s. The first one I owned was a 1970 frame with a '69 motor drag bike. I sold it along with my CB450 when my first child was born. I resisted scratching that itch to get another bike for 19 years. By that time my two sons didn't need to rely on me for transportation, so I sold one of our cars and started looking around for a two wheeler. Bought a new 2012 Honda 750 Phantom Shadow and rode it for @ 2 years, until someone backed OVER it with a heavy duty truck in the parking lot while I was inside the store. It was a total write off that the truck owner's insurance paid off what I owed plus $1000.
I wasn't too upset over the loss because the forward controls became uncomfortable to me on rides longer then an hour due to an old leg injury, and I want a bike that I can do a trip to the four corners of the USA on. (something that I have wanted to do since I started riding in my teens). I also wanted something with a bit more pep. So I started researching bikes for it's replacement. I knew I wanted a UJM Honda for the more comfortable riding stance and something reliable that I wouldn't have to constantly fiddle with like I did with the carbs on my SOHC CB750. Also wanted a big fuel tank for longer distances.
The DOHC CB750s from the early '80 seemed to fit the bill. I started shopping around and a few months later and thousands of ads searched, I found an 1981 CB750K on the local Craig's List in relatively good condition for it's age, wiring was un-spliced, tank not dented, it started right up without smoking. The only immediately obvious problem was the cam chain rattling around, but not a major issue. So it found a new home with me.
First thing was to replace the cam chain and the cam chain guide, the new replacement chain was easy to get, but the damn chain guide took three months to track down an ONS one. It shipped from England and the shipping cost more then the part did. While I was hunting for the chain guide I sent the jugs out to a machine shop to be inspected and cylinders polished. Unfortunately the machinist informed me that the cylinders were no longer round, they had been worn to slightly oval. I bought a salvaged set of cylinders and 4 pistons. The cylinders were in real good shape and I took the best 4 of the 8 pistons I now had and cleaned them up, sanded and polished them while I was waiting for the rebuild kit.
While the motor was out, I stripped everything off the bike and I sanded and painted the frame with three coats of gloss black, decided I didn't like it and preceded to lightly sand the frame again and added two coats of flat black, that looks much better. Replaced the 5 pounds of plastic speedo and tach with Dime City mini gauges that I mounted on a custom bracket made from aircraft grade aluminum. To get the gauges where I wanted them I had to replace the cables with longer ones made for an '81 CB750 Custom. I also used the same aluminum to design a single bracket to mount the rear turn signals, smaller Suzuki tail light, and license plate on. Replaced the plastic brake fluid reservoir with a machined two piece metal reservoir. Upgraded the battery to an AGM then connected and hid the charging plug in the frame so it is a snap to put it on the charger if needed. Sanded and painted the stock exhaust pipes high temp flat black. The 4 into 4 exhaust will be replaced with a 4 into 1 in the future. I swapped out the stock headlight with a rectangle shaped one, it looks better with the square motor and boxy 5.5 gallon tank. Took off the rear pegs and left them off, no passengers on this baby. I replaced the old heavy, worn out stock shocks with adjustable aluminum piggy-back shocks. The seat and pan were in pretty good shape and no need to change it. The fuel tank had light rust inside and a layer of surface rust on the underside of the tank. I filled it with "Metal Rescue" for 24 hours and it was like new inside. I sanded the rust off from underneath and gave it a couple of coats of Rust-oleum, then applied reflective heat shielding over the bottom. Even after 100 miles of highway riding, the underside stays nice and cool. I also replaced the leaky petcock with a brand new one. I chopped off half the rear fender and moved the lights and tag up behind the seat onto the new bracket.
Back to the motor, I baking soda powder blasted the carbon off the inside of the cylinder heads with a home made blasting gun. It also worked good on cleaning the oxidation off the cover of the rear brake and the outside of the motor. Reassembling the engine only had a few hiccups, the cam chain took a bit of finagling to install, I also snapped a piston ring when installing the pistons so had to order a better set from Honda, and try again several days later. The exhaust gaskets I originally got with the rebuild kit were crap tinfoil and paper, so I ordered copper ones from Honda. I replaced the spark plugs with the proper ones and tuned the motor to stock timing specs. I rebuilt the carbs as best as possible without separating them, I still had a tiny vacuum leak on my trip up from Florida to NYC in the outer right carb. I have since taken the carbs off and sent them out to be professionally rebuilt and to fix the leaks, they came back looking like new and since I had done a good portion of rebuilding them, they didn't cost the price of a full rebuild.

Unfortunately, three days before I had scheduled to re-install the carbs I ended up getting sick, and spent a long time in the hospital and ended up having surgery. I am still recovering and am in no condition to wrench on the bike. So for now I can only look at it, plan, and research what my next modifications will be. I know I now need to rebuild the front brakes due to a leak in the calipers.
 

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Here is the 2012 750 Phantom I had that ended under a truck in a store parking lot.
 

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That was a good write up. I'm interested in seeing the gauges. At least you have something to think while you get better. Wishing you a speedy recovery :D
 
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