Topic: "Mouse" - a 1978 CB750K project [PICS]

[Desert-SOHC]

I live in SoCal and we've had the hottest and most humid summer.

its been miserable.

[SOHC4 Cafe Racer Fan]

I live in SoCal and we've had the hottest and most humid summer.

its been miserable.

Ooh.  Yeah.  Menifee has been even worse!

[Vinhead1957]

Dat sure is Purty

[Phinn]

After a year of work, I am happy to report some major progress!

Mouse isn't much to look at, yet. 



It has a few mechanical issues:

• There's no seat. (The PO had a Yamaha seat sort of perched, unattached, on top of the bike when I got it.)
• There's no headlight.
• There's no tail light.
• There's no speedometer (although the tach works perfectly).  The speedo cable is welded to the axle and will need to be drilled out.
• The neutral switch isn't grounding properly.
• The air cleaner box doesn't quite line up with the carbs, due to shrinkage of the carb insulator boots.
• There's a missing air-fuel mixture screw on carb No. 4 (on account of the missing threads into which it screws), which I haven't figured out how to fix. 
• The rear shocks are crap.
• The fork springs are crap.
• The tires are crap.
• The foot pegs are not strictly attached, in the technical sense of the word, on account of the fact I had to cut the bent lower engine hangar bolt to remove it.
• I'm not entirely sure the front brake is going to work.

Yes, I painted the engine covers, but not the cylinders or the head. And the paint job on the gas tank can only be fairly characterized as a work-in-progress. (I wanted to see what a nice cool gray color would look like.)

My approach so far has been to do the bare minimum to get the bike running, to (a) see if I could do it, and (b) see if it's worth investing any more time and money in the project. 

But even with all that, damn if she doesn't fire right up and purr like a kitten.

Thanks again for all the help. This is the best damned forum on the Internet.

[SOHC4 Cafe Racer Fan]

That's a great sound to hear!

[stan.]

as the owner of a K7 currently in pieces (and was bought that way) this thread gives me hope. 

[Restoration Fan]

Man, she sounds good!  VERY nice work, Phinn!

[Phinn]

I had a chance to take the bike for a spin or two around the block, and it runs a lot better over 3k rpms, because of the absent air-fuel screw for the #4 carb.  When the screw is taken out, that cylinder gets an overdose of fuel at idle.  It's misfiring.  At higher speed, the main jets are dominant, and it's less of a problem. 

I can put a screw in, but it only stays in when it's in all the way, which causes it to run too lean (i.e., zero) at idle.  I need to find a way to repair the threads, or I'll have to toss the unit.

On my test run, I used a makeshift seat fabricated from a piece of quarter-inch MDF, two folded up bath towels and a plastic bag. It actually stayed on quite firmly (because of the battery box screws holding it in place), and was surprisingly comfortable, as it molded itself to my posterior.  I'm going to make a real seat, and use this one as a prototype.

It was funny -- I didn't rev it too much in case the oil wasn't circulating properly.  But as I eased the bike up into second gear, the power of the acceleration almost left me lying in the street.  I had to grip the tank with my knees just to stay on.  It may be a 78, but it has some serious pull.

[Phinn]

I'm toying with a few color scheme ideas. The fenders are blacked out and the tank is mostly stripped (of its 4-5 bad paint layers). The original orange/brown 70s era stripe was lurking under there.

[Restoration Fan]

It may be a 78, but it has some serious pull.

Don't let these other guys lie to you, Phinn.  The 78's are the fastest.  Just ask Wilbur. 

[Desert-SOHC]

It may be a 78, but it has some serious pull.

Don't let these other guys lie to you, Phinn.  The 78's are the fastest.  Just ask Wilbur. 

Mine moves right along......ask the squids around here.

[Phinn]

After passing through an ill-advised green phase, the paint on the tank has finally been done.

[Phinn]

Here it is in better light.



It actually runs really well, for looking so rough.  I figured the bike was already so beaten up, and getting it to look really slick would take about 17 years, I might as well run with the post-apocalyptic theme.

The orange logo is from a video game called Half-Life.  In the game, the symbol is used by the human resistance who fight an army of tyrannical space aliens. My son's idea. He's 12.

[SOHC4 Cafe Racer Fan]

Here it is in better light.



It actually runs really well, for looking so rough.  I figured the bike was already so beaten up, and getting it to look really slick would take about 17 years, I might as well run with the post-apocalyptic theme.

The orange logo is from a video game called Half-Life.  In the game, the symbol is used by the human resistance who fight an army of tyrannical space aliens. My son's idea. He's 12.

I thought it looked like the HL logo. I haven't played that game in years.

[Gene]

I like it. As long as that engine gets you where you need to be make it look however you like.  Kinda dig the logo - obscure enough.  I've always like the idea of having the best performing machine and having it look odd, or bad, enough to where no one would look at it twice - a sort of ghost.  Do not misunderstand, I actually think your bike looks great.

[SOHC4 Cafe Racer Fan]

Yes, not to be misunderstood, the bike is coming along.

[Phinn]

I like it. As long as that engine gets you where you need to be make it look however you like.  Kinda dig the logo - obscure enough.  I've always like the idea of having the best performing machine and having it look odd, or bad, enough to where no one would look at it twice - a sort of ghost.  Do not misunderstand, I actually think your bike looks great.

Thanks! I know the paint job is a bit of a goof, but the bike really is something of a wreck, and my goal was to get it running, and to my astonishment, it does.  Painting the tank with a video game motif gave my son and I something fun to do together.

Plus, if an apocalypse does occur, that's one less thing that'll need doing.

There's still a ton of work to do.  After I get the seat, pipes, wheels, shocks, fenders, control switches, gauges, lights and footrests the way they're supposed to be, then I'll circle back around and redo the tank to something a little more polished.