Topic: New to bikes, and current owner of a 1977 cb550f (project basketcase).

[megarawdeal]

Hello all,
   I recently purchased a 1977 CB550F frame, wheels, front end, and various other odds and ends for $50. I plan on building it from the bottom up as a bare bones cafe racer, and would like to do so on the cheap. I'd like to build something very minimalistic as far as the electrical system and accessories are concerned. It would be great if I could just get away with a kick start, magneto ignition, and a voltage regulator for the tail/headlight.
  The first step is cleaning up what I've got.... and then I'll have to source a motor/trans and various other related components. I was just wondering if anyone had any recommendations as to which year cb550 motors/trans are the best, and whether or not there where any other parts for this bike to look for, or stay away from.

Unfortunately I'll most likely have to sit on this project for a few months while I deal with moving and various other priorities, but I couldn't pass up the chance to acquire the foundation for a bike that I've been wanting to build for a long time. In the meantime I'll be planning ahead.
Here are some pictures of "project basketcase".


Here is a hideous wind screen that was included....

[megarawdeal]

Just priced magneto ignition systems for this bike and it's probably not going to happen unless I can retrofit an older magneto system to work on the cb550 engine. Sounds like more trouble than it's worth. I plan on doing somewhat of an aviation themed build on the bike. I will be fabricating the rear seat fearing, and possibly the tank out of riveted aluminum. Airplanes commonly use an integral fuel tank built into the wing with either a bladder, or sealant to keep the fuel from leaking. Using the sealant method would produce the look that I'd like, and eliminate the need for welding. Should be easy to build, and quite functional.
Any input would be greatly appreciated.

[megarawdeal]

I'm currently without a motor but a buddy of mine has an 82 cb750 motor/gearbox with some minor top end issues that he would be willing to give me for free. I know that modding my cb550 frame to shoe horn the 750 engine into would be a major undertaking, and am now debating whether I should scrap the current cb550 project in favor of a cb750 build. I'm not sure whether it would be easier to source the parts that I need for m cb550, or pick up the 750 motor and source a complete 750 with a bad motor. A lot of it has to do with cost and time, and the cb750 seems to be more common. Maybe someone would be willing to swap their 550 motor for my 750? choices choices....

[Stev-o]

First off, welcome!

You being new to bikes, what you have in mind is quite a project. Haven't heard of anyone "shoehornin" a 750 into a 550, but that doesn't mean it can't be done.
But will take some major modifying.
You don't mention what type of skills you have, but this isn't something I would try unless I had a metal shop w/the necessary tools and a checkbook.

Most times, these bikes we get cheap end up costing more that if you found a decent runner to start off with.

Not trying to dissuade you, just giving you my thoughts.

Good Luck.

[megarawdeal]

I'm an aircraft mechanic with a background in automotive, so I'm comfortable with anything other than welding. I've gotten over my head on projects before, but I just couldn't pass up this pile of junk for $50. It was an impulse buy for sure, but I'm betting that I can source the parts to build it the way I want it without spending over $1500. I may just get the bike squared away as a roller for now, and wait for the right motor to come around.

[Stev-o]

Oh, well that makes a big differance! For $50, you got a great deal. That tank alone is worth 50.
If you're not in a hurry, you can def find a motor [post a thread in the bikes/parts wanted section].

If you haven't seen it yet, we are very passonate about these bikes!

[fergie]

In case you did not know a cb 650 motor will bolt right up to that frame.

[Old75_ratafe]

Hmm giving me ideas now I am about to aquire a cb650 from a friend with no motor / trans for $30... was gonna part it... but... hmmm lol.  I would be willing to bet with some time you could make the 750 work but the larger engine would kill the small frame cafe look / handling and be A LOT of work.  My suggestion.  Horse trade someone the 750 engine (fix the minor head problem first? maybe) for a 650 engine get some cheap carbs and rebuild them, cheap 4 into 1 exhaust and call it a bolt in.

[megarawdeal]

Trading the 750 for a 650/550 would be a perfect option. I'd like to go with the 550 so that I could have a kick start. I'd love to be able to run it without a battery, but I'm still not sure how I would go about doing so. It seems like a magneto ignition would be the only way to run it without a battery, and that option looks to be quite pricey.

[Old75_ratafe]

My buddy runs his 750 with points and no bat just kick.  Even a mag trigger like a dyna S you just need enough juice to spark the coils.  My bike has a bum bat dyna s and dyna 2ohms and will spark just enough to catch with the kick and less than 10 volts.  You basically could use a small 12volt bat with just enough juice to light the lights and get the coils initial charge.