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Veloandy's 1977 CB750F

Veloandy

CB750 Member
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Location
Fort Collins, CO USA
Hey Everyone,

Thought I'd post the story of my 1977 CB750F. All my moto-buddies have newer bikes, and all of my gearhead buddies are into 4-wheeled vehicles, so I'm hoping this forum will be a nice way to keep track of what I've done and maybe get some emotional support!

I bought my bike from my brother-in-law about a year ago. Back in college I had a completely thrashed and crashed 1982 Yamaha 550 Seca. I took a break for bikes for a couple of years and then rode around on a 1981 Yamaha XS400 for years, but I sold that and all of my moto gear about 7 years ago. I hadn't planned on getting another bike, but my brother-in-law got the opportunity to move out of the country and offered me a good deal on his totally amazing-seeming CB750 and I couldn't resist. Here's a pic of my CB750 as I got it:
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He had done a lot of good work to it, but then it had mostly sat unused for many years:
  • Bike was stripped and frame and misc parts were powder coated black.
  • Upgraded front master cylinder (brembo) with braided brake line
  • Fresh brake pads all around
  • Front and rear brake calipers rebuilt
  • New Progressive suspension shocks
  • New (13-years-ago) Avon Tires
  • New chain & sprockets
  • Custom Engine & valve Covers
  • Pod Air filters
  • New unpainted, custom-made side covers
  • New battery
  • Forks just serviced
  • New steering bearings
  • Napoleon bar end mirrors
  • New custom front & rear turn signals
  • Reupholstered seat

It was definitely a cool bike and was kind of ridable...but its years of hibernation meant that it needed some attention. The brake lights didn't work (dead pressure switch). The tail light was cracked. The grab rail was cut in half and only held on by one bolt on each side so it was super-hard to get on the center stand (b/c you couldn't lift by the grab rail). The seat attachment was hokey. All of the packing had been blown out of the muffler. The carb balance tubes were uncapped so it had a massive vacuum leak. 3 of the pilot jets were blocked by crud, and the carb needle setting made it run super-lean (so it had flat spots and backfired through the carbs a lot). The fuel line was run strangely and kinked off. The tank had a quickie, flat-black rattle can paint job.

So, I started working on it. I fabricated a metal fuel line from brake line. I got a new pressure switch, bled the brakes after installing it and fixed the brake lights. Got a non-cut-up stock grab rail and non-cracked tail light lens from ebay. Tore down the carbs and raised the needles up one slot (which required me to buy genuine JIS screwdrivers -- those are THE BOMB)! Re-packed the muffler.

One day I knocked over a big piece of angle iron in my shed that struck the flat black tank and made a dent in it...so I decided to properly fix it up. I filled the dent in the tank with AllMetal filler, sanded/primed/wetsanded/primed over and over again. Then I sprayed the tank, side panels, and tail with gloss black Rustoleum from a rattle can that I heated up in a pot of hot tap water. It flowed out beautifully! After letting it cure for a couple of weeks I sprayed it with a coat of 2-part rattle can clear (for gasoline resistance). At this point it was looking pretty awesome and running great:
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I liked owning it. I liked working on it. But...I hardly ever rode it. I decided the excuse I needed to get out on my bike was a solo moto-camping trip to Veedawu in Wyoming to see the Pleiades meteor shower. So I rigged up a saddle bag out of a Swiss army surplus M90 rucksack that I bought for $23 at Jax, a local army/navy/surplus/outdoor store (same pack as this), loaded it with backpacking gear...

Then I noticed that my rear tire was cracking at the tread. I looked at the tires' date codes and they were ancient and dangerous. I ordered some new cruiser-style tires in close-to-stock sizes from Revzilla, spent a few sweaty hours mounting them and rupturing the tubes, and ended taking them to Interstate Honda here in Fort Collins to get them mounted. The dudes at Interstate Honda were awesome, fast, and friendly. They got the job done and I hit the road!
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The bike ran AMAZINGLY! It was so fast, and stable and smooth! My speedo needle was bouncing between 80 and 90 mph and the bike loved it. It was my first long (1.5 hours each way) ride in 20 years. My first ride ever with armored pants and earplugs. I loved it. The meteor shower was great. The stars were amazing. It's SO COOL when a meteor shower and a new moon and a clear sky all happen on the same *weekend*!

The one problem was...
<To Be Continued>
 
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The one problem I had on my camping trip: As I rolled into Laramie Wyoming, I scrubbed off speed with the front brake. Everything was good. I went to turn into a gas station, doing the MSF slow-speed maneuver of playing with slipping the clutch vs. riding the rear brake, and was shocked that the rear brake did nothing. I compensated, made it to the gas pump, got off the bike and saw that the back was covered in oil!!

Oil on my license plate. Oil on my rear tire. Oil on my rear brake rotor (why the back brake didn't do anything). I overfilled the oil when I first got it because I didn't expect the oil tank to drain to the sump when it was cold and made a big mess...but I wasn't overfilled when setting out on the trip.

I decided to press on...checking frequently that I still had oil in the tank and being sure not to lean the oily, slippery rear tire way over in turns. I made it, but the whole ride home I was thinking "where could this oil be coming from!?!?" and "Is my oily rear tire going to let go on this next curve?". It was much less relaxing than the drive up.

When I got home, I checked out some forums and saw that when the engine runs at close to 7000 RPM for an extended period of time, the oil tends to foam. I looked at some diagrams of the stock air cleaner and it looks like it has an air/oil separator that drains back to the oil tank. When my brother-in-law installed the pod filters, he ran the crankcase breather down to the frame by the center stand, and it looked like the oil foam was just spraying from there to the rear of the bike.

When I got home, I installed this oil catch can at the crankcase vent. It doesn't drain back to the oil tank, but I thought I'd give it a try and see how much oil it accumulates before deciding if I need to plumb an oil return to the tank.

To test it out, I decided to take an epic ride on a Saturday. The Friday before I was running some errands on my bike and the oil light came on at idle! Thanks to some forum posts I saw that the problem could be the oil pump O rings. So Friday night I dropped the 4-1 exhaust, drained the oil, pulled the pan, and dropped the oil pump. Since I was at it, I decided to change the oil too and was dismayed to find that the oil filter housing was missing its spring.

So, Saturday morning, instead of heading off on an epic moto ride, I was back at Interstate Honda, buying an oil spring, an oil filter, expensive motorcycle oil. Then I hit Harbor Freight for a metric O-ring assortment, and ran a bunch of other errands. Saturday night I put in new oil pump O-rings, cleaned out the anti-drainback valve on the oil pump, sealed up the oil pan on the crankcase, and let my gasketmaker dry overnight.

Sunday morning, I put in fresh moto oil and headed out on this ride up to Estes Park (entrance to Rocky Mountain National Park). It was less epic than the one I had planned but still amazing and fun! The oil light stayed off at idle. I had no leaks. No appreciable oil accumulated in my catch can.

But when I got gas when I got back home I saw I had a new problem: The Kreme liner was separating from the top of my tank. I grabbed the Kreme liner with some pliers and pulled out a big sheet (in the foreground in this pic):
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So...I drained the gas from the tank to my gas can. Managed to spill a bunch more gas when I pulled my petcock in the garage, making my whole house reek of gasoline (sorry wife and kiddos!). Pulled the tank, and set it in my shed. After work last week I stopped by Walmart and bought a gallon of acetone. I blocked off the petcock hole and the filler with aluminum HVAC tape, and dumped in the acetone to dissolve the rest of the Kreme.

I left the acetone in overnight. Then I dumped a bunch of BBs and drywall screws in the tank and shook it up with the acetone. The acetone did a good job. Almost all of the liner came out when I drained the nasty, oatmeal-like mess of milky acetone and Kreme chunks. I aired out the tank, rinsed it with a bunch of water, and then (with the BBs and drywall screws still inside), put the tank in a yard trash bag, wrapped it in some old comforters, and put it in my dryer with no heat for 40 minutes. The BBs and screws did a good job beating out the remaining chunks of Kreme and rust.

I pulled all the BBs and screws out with a magnetic pickup tool, and rinsed a lot of surface rust out of the tank with water. I set the tank in the sun and ran my shop vac hose (in reverse) to the tank to blow air through it for about an hour to get it all dry.

I managed not to damage the paint job except for under the fuel filler door. I hit that with some bed liner and it turned out well:
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So, now I'm waiting my my Dragon's Blood Caswell tank sealing kit...it should be here next weekend...my bike is mothballed until then. Once that's done I'll finally take my epic ride if it's still warm enough and decide if I want to keep it.
 
That's a nice looking bike. From your story, I'd say you should own at least one at any given time ;)
 
Since I'm sitting on my hands, waiting for my tank sealer to arrive, I decided to bust out the sewing machine and make a simple tool roll.

My seat attaches in a kind of hokey way, so I need a Phillips head screwdriver to take it off, so I needed somewhere other than the "tool tray" to stash my tools.

I used a 24" X 24" piece of 1000D Cordura, some 2" webbing, some D-rings, and some velcro that I had left around from a previous project. I used an old Kenmore sewing machine with extra-heavy-duty nylon upholstery thread to put it together. I'm pretty satisfied with how it turned out.

My emergency tool kit: (JIS screwdriver, test light, adjustable wrench, combination wrenches, allen wrenches, and vice grips):
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They all slip into the pockets:
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The whole kit rolls up and is secured by the 2-inch webbing with D-rings around the roll and 2-inch webbing with velcro around the fork legs:
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It tucks in under the headlight pretty securely and inconspicuously:
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It will be super-nice to have my tools with me by default!
 
FedEx dropped off a box full of Dragon's Blood from Caswell coatings at my doorstep yesterday!! I coated my tank and it turned out great!
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I got the 10-gallon-tank kit, but not a lot drained out from my 5ish gallon CB750F2 tank. The coating flowed really slowly, so I had to peek in the filler neck a lot to make sure I wasn't missing any spots.

The coating tended to run off of the ridge in the middle/bottom of the tank, leaving it looking thin and translucent there, so as the epoxy firmed up and got gummier, I spooned a couple extra dollops of mixed epoxy onto the ridge right before the filler neck.

I'm taking my VW van camping this weekend, but if the weather is still nice the next weekend, I'm fully taking my moto on an epic ride!!

In other news, I signed up for the Distinguished Gentleman's Ride on September 30th. I'm totally stoked! It seems like a good cause. I hope to meet some cool folks and see some neat vintage bikes. It could be a lot of fun, but I'm a little worried it will attract too many hipster posers. Has anyone here ridden one before? This will be my first one.

I tend to be more on the ATGATT end of the spectrum, but the Distinguished Gentleman's Ride is all about not riding in motorcycle gear. So, in the meantime, I'm going to bust out my sewing machine and try to rig up some under-the-suit-and-tie compression armor for the DGR. I'll post pics if I have time.
 
I doubt that toolkit will stay there. It needs something solid to support the weight so the Velcro only has to hold it in place.

I notice right off 2 important things missing from your kit. Spare fuses and a plug socket!

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PS Great craftsmanship on that tool holder.
 
Thanks Dave! Excellent call on including fuses and a spark plug tool. Some wire and electrical tape would probably not be a bad idea to include too.

The toolkit is mostly supported by 2 long studs that stick out of the bottom triple tree. They look factory. I’m not sure if they held the original turn signal/horn assembly, or if they are some kind of factory provision for a fairing. Either way, they’re functioning as a pretty solid tool toll shelf now!!

Thanks for keeping up with these silly updates!
 
Oh, and the 1/4" extension is for turning the plug socket because trying to do it with the cheap screwdriver is a bitch! There may have been a rod for it but you can see the tool kit is not 100% original.
 
New to the site and to the 750s. Not new to the horrors of Kreem, however. Like you, I had a poorly Kreemed tank (including covering the pickup screens) in my GL1000 and removed it with acetone. Not having a ready safe disposal facility, I returned the acetone (now full of Kreem chunks and disolved) to the cans. Four years later, I have found that tha Kreem is now a congeled lump in the bottom of the can, and I'm using it to disolve ancient varnish left in my 750 tank (filtered through a paint strainer).

Kreem is a devil! I went with just keeping my GL1000 tank filled with non-ethanol gas with a little stabilizer.
 
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