Ranger's 1980 CB650C Scrambler build

[Volker_P]

I really like this "machining from solid steel" project.
10.9 sprocket bolts!

[Ranger]

i was kind of anticipating this. I’ve been working in the bike while it’s on its center stand. Now that I have the rear wheel figured out, I decided to take the bike off the lift to check the stance. When I folded up the center stand, my suspicions were confirmed. If I want to keep it, I’m going to have to either fab a new one, or modify the existing one. I’ll also need to fabricate a new stop, since I did away with the factory exhaust.

Of course, I still might take the easy way out and do away with the center stand all together. They sure make it easy for roadside repairs, though.

If I do keep a center stand, I’ll likely keep the factory pivot as a starting point and fabricate off of that.

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[Ranger]

I never liked the 1980 tank, so I’ve been looking for an early- to mid-70s Honda tank to put on my build. I ended up settling on a CB550 tank. If you use the front cb550 tank rubbers (same ones as in the cb750 and several other bikes) you don’t have to modify the front mounts. There are the same diameter as the cb650 rubbers, but a bit longer. For the rear mount. I intend to use the factory cb650’rubner mount. I’m just going to make a bracket that I’ll weld to the existing cb550 tank’s rear bracket.

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[Ranger]

I also finally finished rebuilding my carbs. I had the bodies vapor honed by my friend Daniel, ownder of Pandemonium Custom Choppers. Internals came from 4into1.com, JetsRUs, and motorcycleproject.com. The air cleaner came from Steel Dragon Performance.

I had a hard time sourcing orings for the fuel crossover tubes and the accelerator pump circuit crossover tubes.

I found a thread on here that suggested 007 orings for the accel pump circuit and 010 orings for the fuel crossovers. The 010 orings did work, but the 007 orings were much too big. I even tried 006 and 005 orings, and while the ID was good on the 005, they were too thick.

I ended up using some orings out of a metric assortment a friend of mine had. The size was 2.2MMx1.6MM. That means I stretched the orings a little more than normal, but they had a good fit otherwise, so I’ll run them and see what happens.

If somebody knows the actual o-ring size, please let me know.

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[Ranger]

Here’s one with the air cleaner...

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[CB650SC-C]

Wow they look good

When I had the 650Z before the 650SC-C, I found that those Carbs gave a big flat spot when you opened it up, whereas the CV's flowed noticeably better. Although to be fair, how well tuned/jetted they were was unknown .

[Solomoriah]

My 1980 CB650 lags a bit when you roll on the power around 4,500 to 5,500 RPM. It was worse when I got it, but I did a homemade version of the air box to carb vent connection they issued as a fix. Thing is, those slide carbs are so quick the rest of the time that the laggy part is really no worse in my opinion than the slight inherent lag of CV carbs.

Biggest problem for me is carrying a passenger; the power rolls on kind of abruptly when starting out.